Polyethylene polymer blends and methods of making and using thereof

Abstract

Described herein are blends of disentangled ultra-high molecular weight polyethylene (UHMWPE) with high-density polyethylene (HDPE), as well as methods of making and using thereof. The blends are typically homogeneous blends and these can be used in the manufacture of plastic articles or products. The blends can also be used to form melt-spun fibers.

Description

[0001] Attorney Ref. #:KAUST 2023-130-02 PCTPOLYETHYLENE POLYMER BLENDS AND METHODS OF MAKING AND USING THEREOF CROSS REFERENCE TO RELATED APPLICATIONS This application claims priority to and the benefit of GB 2402137.0 filed on February 15, 2024, the entire contents of which are incorporated herein by reference for all purpose in their entirety. FIELD OF THE INVENTION The invention is generally directed to blends of disentangled ultra-high molecular weight polyethylene (UHMWPE) with high-density polyethylene (HDPE), as well as methods of making and using thereof. BACKGROUND OF THE INVENTION Polyolefins, such as polyethylene (PE), are one of the largest classes of synthetic polymer made and used commercially today. These polyolefins possess features that have made them the most widely used type of synthetic polymers, such as due to their low cost of production, abundant supply of cheap and simple monomers, along with well-established reactor engineering and catalysis[1]. Additionally, their mechanical properties can be engineered and controlled through co-polymerization, blending, and use of additives, which permits their use in a wide range of applications. An important factor that plays a significant role in the properties of polyolefins is their weight-molecular weight (Mw). Compared to the commodity low molecular weight PE, the ultra-high molecular weight polyethylene (UHMWPE) having Mw greater than 1 million g / mol has far superior mechanical properties that enable their implementation in various engineering applications. The high strength, combined with the lightweight, made it possible to use UHMWPE in the fabrication of ballistic armors as well as in medical applications such as prostheses2, 3. However, the enhanced physical and mechanical properties arise at the cost of its processability. With increasing Mwof the polymer melt, beyond the critical molecular weight (Mc), the zero-viscosity (η0) increases following the power law (η0 ~ Mw3.4)). Hence, due to its ultra-high molar mass, the melt viscosity of UHMWPE increases to an extent that the conventional processing methods cannot be employed. The blending of UHMWPE with the commercial low-molecular weight PE matrix, such as high-density polyethylene (HDPE), holds a potential in overcoming processing 1 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTchallenges via conventional routes and enhancing mechanical properties of the commodity plastic. However, homogenous blending of the two extreme molar masses imposes challenges. Using various techniques, many attempts have been made to homogenously blend UHMWPE and HDPE, including solution blending, melt-blending, and in-situ reaction- blending4-12. While solution-blending is the most common blending approach in academia, it is highly undesired in industry due to complications of the solvents, including the added expenses, difficulty in removing the solvents from the resultant polymer, making it highly pollutant to the environment4. On the other hand, melt-blending is the preferred method in industry due to its scalability and compatibility with the industrial processes, such as extrusion and injection molding5. However, achieving homogenous blending of UHMWPE in HDPE via melt-blending technique is very challenging due to major differences in viscosities of the two polymers6. Boscoletto et al. showed that only as high as 3 wt.% of UHMWPE can be melt-blended in HDPE matrix, and that higher contents of UHMWPE leads to an immiscible phase in the matrix7. Additionally, Li et al. showed that melt-blending 5 wt.% of commercial UHMWPE in HDPE matrix led to two immiscible phases8. Alternatively, in-situ reaction blending has also been investigated by various groups[10-13]. For example, Kurek, et al. synthesized trimodal reactor blends of PE via multiple single-site catalysts system

[0010] . Their blends included a low molecular weight PE wax, HDPE, and UHMWPE with ultra-broad distribution (Ð). They incorporated UHMWPE content of 16 wt.%, with Ð reaching up to 420. Additionally, Hofman, et al. pioneered an approach where they synthesized bimodal reactor blends (wax / UHMWPE) and then melt blended with HDPE

[0011] . The presence of PE wax facilitates melt blending of UHMWPE with HDPE, allowing them to incorporate up to 12 wt.% of UHMWPE in HDPE matrix. Similarly, Szántó, et al. adopted the same technique, resulting in multi-modal weight distribution blends containing UHMWPE content up to 20 wt.% with Ð of 1600

[0013] . However, in-situ reaction blending suffers from complex interactions between the polymeric chains of different molecular weights (Mw), leading to difficulty in controlling the mechanical and thermal properties of the blends produced

[0014] . Furthermore, in-situ blending produces unrealistically ultra-broad distribution (Ð), which poses a major challenge in predicting and modeling the 2 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTrheological behavior of these polymeric blends

[0015] . Moreover, the presence of high content of PE wax in such in-situ formed blends are known to weaken the mechanical properties

[0016] . Chaudhuri et al. melt-blended UHMWPE with HDPE with a maximum UHMWPE content up to 10 wt.%17. They reported that only 50-70 wt.% of the added dis-UH in HDPE matrix can be dissolved via solely melt blending route within a residence time of 5 minutes. In their work, the maximum dissolved content of dis-UH in HDPE was reported to be 5.5 w.t % (for the added 10 wt% of dis-UH in HDPE). Albeit the dis-UH has the potential to enhance the existing commercial grades of PE via industrially viable route, there is a lack of research work investigating the rheological and mechanical properties of HDPE / dis-UH blends. Despite the many attempts made to homogenously blend UHMWPE into a PE matrix using various techniques, including solution blending, melt-blending, and in-situ reaction- blending techniques, there remain challenges in the incorporation of an UHMWPE component into a commercial low-molecular weight PE matrix, to provide blends having polydisperse molecular weight distributions and improved mechanical properties while preserving processability by conventional melt-processing techniques. Therefore, it is an object of the present invention to provide blends of UHMWPE in a PE matrix. It is a further object of the present invention to provide methods for forming such blends. It is still a further object of the present invention to provide methods for using such blends. SUMMARY OF THE INVENTION Described herein are melt-blends of dis-UH with HDPE matrix and methods for their formation. In one non-limiting instance, a method for preparing a blend including a disentangled ultra-high molecular weight polyethylene in a polyethylene matrix, includes the steps of: (i) mixing a polyethylene and a disentangled ultra-high molecular weight polyethylene; (ii) placing the mixture of step (i) into a compounder; and (iii) exposing the mixture to melt-blending conditions to form the blend including the disentangled ultra-high molecular weight polyethylene in the polyethylene matrix. 3 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTTypically, a homogenous blend including a disentangled ultra-high molecular weight polyethylene in a polyethylene matrix is formed. In some other instances, a homogeneous blend is provided which includes a disentangled ultra-high molecular weight polyethylene in a polyethylene matrix, where the disentangled ultra-high molecular weight polyethylene is present at a concentration ranging from greater than about 5.5 wt.% to about 20 wt.% of the total weight of the homogeneous blend. The blends of disentangled UHMWPE and HDPE disclosed and formed according to the methods of making above can be used in the manufacture of articles and products. Such articles or products can be formed by solid-state and melt processing of the blends described, where the solid-state and melt processing can include extrusion and / or injection molding of the blend in order to form the article or product. BRIEF DESCRIPTION OF THE DRAWINGS FIG.1 shows a non-limiting schematic illustration of a preparation method for blends of ultra-high molecular weight polyethylene (UHMWPE) and high-density polyethylene (HDPE), including blending and molding, as well as exemplary testing methods used to evaluate the blend samples. FIG.2A shows a graph of the storage modulus buildup (G’) as a function of time for pure HDPE, dis-UH, and eUH at 160 °C, 10 rad / s, and 0.2 %. FIG.2B shows a graph of the frequency sweep of pure HDPE, dis-UH, and eUH at 160 °C and 0.2% at equilibrium. FIG.3A shows a graph of the relationship between critical capillary number as a function of viscosity ratio between the added polymer to the matrix adopted from

[0026] , in additional to the actual complex viscosity ratios of dis-UH and eUH to HDPE matrix using the chosen residence time (5 minutes) and shear rate (70 rad / s). FIG.3B shows a graph of the buildup of complex viscosity of dis-UH and eUH normalized by complex viscosity of HDPE matrix as a function of residence time at a specific shear deformation rate of 70 rad / s and 190oC, which mimics the melt- blending conditions. FIG.3C shows a graph of the influence of shear deformation rate at the complex viscosity ratio, measured immediately (thick lines) and after 1.5 hours (open symbols). 4 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTFIG.4 shows a graph of the weight-average molecular weight (Mw) with increasing wt.% content of dis-UH (square symbols) and eUH (round symbols) in an HDPE matrix. FIG.5A shows differential scanning calorimetry (DSC) curves of HDPE, dB01, dB02, dB05, dB10, dB20, and dis-UH from 40 to 160 °C at 10 °C / min. FIG. 5B shows DSC curves with annealing at 190 °C for 5 minutes. FIG. 5C shows DSC heating and cooling cycles used to evaluate pure HDPE, dB10, dB020 and dis-UH. FIG. 6 shows a graph of the stress-strain curves of pure HDPE, dB05 and dB010 performed at room temperature according to ASTM D-412-D standard. Yield point and Young’s modulus increased with increasing wt.% content of UHMW components in the HDPE matrix. FIG.7A shows a bar graph of the average of yield strength (^yield,avg) for pure HDPE, dB05, and dB10. FIG.7B shows a bar graph of Young’s modulus (Eavg) for pure HDPE, dB05, and dB10. FIG.7C shows a bar graph of the strain at break (^break,avg) for pure HDPE, dB05, and dB10. FIG. 8A shows a graph of the storage G’ (squares) and loss G’’ (circles) moduli as a function of angular frequency for pure HDPE, dis-UH, and dB10, including SAOS (filled squares and circles) and creep (open squares and circles) for selective data as indicated in the legend. The straight faded lines represent the Mead model fits. FIG. 8B shows a graph of the complex viscosity as function of angular frequency (filled symbols) for all the samples studied here as indicated in the legend, while the lines represent the Cross model fit. FIG.9A shows a schematic illustration of a long chain tube in presence of fast constraint release by adjacent short chains. FIG. 9B shows a schematic illustration of a short chain reptation tube in presence of slow constraint release caused by adjacent long chains. FIG.10A shows a graph of the zero-shear viscosity (η0) as a function of weight average molecular weight (Mw) for the pure polymers and blends discussed in the examples, together with those obtained from the literature, as indicated in the legend. FIG. 10B shows an enlarged image of the data obtained and discussed in the examples. 5 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTFIG.11 shows a graph of the activation energy for HDPE, dB05, dB10, dB020 and dis-UH obtained from the horizontal flow shift factor of TTS. FIG.12A shows a graph of the molecular weights (Mw, Mn, and Mz) and distribution (Ð) with increasing content of low-enUHMWPE (dis-UH) in HDPE matrix. FIG.12B shows a graph of the corrected zero-shear viscosity (η0, corrected) and the reptation molecular weight (Mr). FIGs.13A-13D show SEM images of the surface of the extrudate for (FIG.13A) pure HDPE at scale of 100 µm and (FIG.13C) 50 µm, and for (FIG.13B) dB05 at 100 µm and (FIG.13D) 50 µm. FIG.13E shows the Young’s modulus of Pure HDPE, dB05, and dB10 against crystallinity obtained by DSC and compared with linear PE data from literature

[0025] . DETAILED DESCRIPTION OF THE INVENTION Blends of disentangled ultra-high molecular weight polyethylene (UHMWPE) with high-density polyethylene (HDPE), as well as methods of making and using thereof are described herein. I. Definitions The terms “disentangled ultra-high molecular weight polyethylene (UHMWPE),” “low entangled ultra-high molecular weight polyethylene (UHMWPE), “dis-UH,” and “dUH,” are used interchangeably herein. These terms refer to a form of ultra-high molecular weight polyethylene (UHMWPE) which is a polyethylene polymer of a high molecular weight, typically in the range of millions of grams per mole, where the polymer chains have been untangled or disentangled to at least some extent, as compared to entangled forms of ultra-high molecular weight polyethylene, which are obtained from commercial sources. As compared to entangled UHMWPE, the disentangled forms of UHMWPE have a lower extent of entanglement of the polymer chains present within. Numerical ranges disclosed in the present application include, but are not limited to, ranges of integers, ranges of concentrations, ranges of times, amongst other ranges disclosed below. The disclosed ranges, disclose individually each possible number that such a range could reasonably encompass, as well as any sub-ranges and combinations of sub-ranges encompassed therein. For example, disclosure of a range of concentrations is intended to disclose individually every possible value that such a range could encompass, consistent with 6 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTthe disclosure herein. For example, a concentration range of about 5 wt.% to 10 wt.% also discloses each weight concentration within the range individually (e.g., 5, 5.6, 6, 6.8, 7, 7.1, 8, 8.4, 9, 9.9, 10, 10.11 wt.%, amongst others), as well as any sub-range contained therein (e.g., about 5.2 to 8.5 wt.%). II. Blends of Disentangled Ultra-High Molecular Weight Polyethylene (UHMWPE) and High-Density Polyethylene (HDPE) Melt-blending UHMWPE with HDPE presents a cost-effective means of enhancing the mechanical properties of commercial polyethylene (PE) grades. Nevertheless, direct use of commercially available UHMWPE poses challenges due to its exponentially high melt- viscosity, attributed to the existence of entangled ultra-long polymeric chains. As a result, its practicality with industrial processing methods, such as extrusion and injection molding, is limited, often resulting in uneven mixing. By contrast, the use of dis-entangled UHMWPE (denoted dis-UH) can be a viable alternative solution due to its lower entanglement density in the nascent metastable phase, and therefore reduced melt-viscosity compared to the commercial fully entangled UHMWPE (denoted eUH). In some instances, entanglement density can be estimated from isothermal crystallization experiments obtained from DSC where equilibration kinetics can be estimated by the quantification of the area ratio between the low and high melting temperature peaks after the crystallization step of the polymer. Accordingly, another approach to blend UHMWPE with HDPE is described herein using a low-entangled state of UHMWPE (dis- UH). Such dis-UH can be synthesized via a single site catalyst, as described in Rastogi, et al. where it was shown that the dis-UH synthesized via single cite catalyst exhibited lower melt- viscosity, as compared to commercial fully entangled counterparts

[0017] . The reduced viscosity of such dis-UH and their higher diffusion coefficients facilitates the dissolution of UHMWPE in an HDPE matrix via a solvent-free melt-blending route with a relatively narrow Ð, as compared to in-situ reaction blends

[0015] . Described herein are melt-blends of dis-UH with HDPE matrix and methods for their formation. These blends can be characterized, for example, by means of capillary number and viscosity ratio between the added dis-UH to HDPE matrix. The homogeneity of such dis- UH / HDPE blends with, for instance, weight fractions of dis-UH up to 40 wt.% are further characterized by examining: the linear viscoelastic (LVE) response, the scaling law of zero- 7 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTshear viscosity (η0) and molecular weight (Mw), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and tensile properties of such blends. In one non-limiting instance, a method for preparing a blend including a disentangled ultra-high molecular weight polyethylene in a polyethylene matrix, includes the steps of: (i) mixing a polyethylene and a disentangled ultra-high molecular weight polyethylene; (ii) placing the mixture of step (i) into a compounder; and (iii) exposing the mixture to melt-blending conditions to form the blend including the disentangled ultra-high molecular weight polyethylene in the polyethylene matrix. In another non-limiting instance, step (i) is omitted and step (ii) is instead a step wherein the polyethylene and the disentangled ultra-high molecular weight polyethylene are simultaneously fed into a compounder (to form a mixture in situ). Although the methods are not particularly restricted to a polyethylene, it is preferred to use a high-density polyethylene (HDPE) and HDPE matrix. In some instances, step (i) of the method can further include the addition of an antioxidant additive, where the antioxidant additive can be present at concentration of, for example, at least about 1 to 1.5 wt.% of the mixture formed during step (i). In some instances, the antioxidant additive is an IRGANOX® additive, such as known in the art. In some instances, the IRGANOX® additive is IRGANOX® 1010. Other classes of antioxidants are known in the art. In some instances, the melt-blending conditions of step (iii) include heating the mixture to a temperature of at least about 100 °C, 125 °C, 150 °C, 175 °C, 180 °C, 185 °C, 190 °C, 195 °C, 200 °C, 225 °C, 250 °C, 275 °C, 195 or 300 °C; or to a temperature in a range of between about 100 °C to about 300 °C, as well as individual temperatures or sub- ranges contained within. In some instances, the melt-blending conditions of step (iii) include heating the mixture to a temperature of about 190 °C. In some instances, mixing at higher temperatures is possible, such as 280 °C in inert atmosphere. Lower temperature ranges are also considered possible, starting just above the melt temperature of the chosen HDPE used in the method. In some instances, the heating temperature is selected to be higher than the melting temperature of the polyethylene. 8 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTIn some instances, the melt-blending conditions of step (iii) include applying a shear deformation of at least about 10 rad / s, at least about 20 rad / s, at least about 30 rad / s, at least about 40 rad / s, at least about 50 rad / s, at least about 60 rad / s, at least about 70 rad / s, at least about 80 rad / s, or at least about 90 rad / s; or applying a shear deformation in a range from about 10 rad / s to about 90 rad / s, as well as individual values or sub-ranges contained within. In some instances, the melt-blending conditions of step (iii) include applying a shear deformation of about 70 rad / s. In some instances, the melt-blending conditions are applied to the mixture for a residence time sufficient to provide a homogeneous blend of the components, where such a residence time can vary depending on the applied shear rate, and can be in range from a few seconds to several hundreds of seconds (such as from about 5 seconds to about 2000 seconds, as well as individual values or sub-ranges contained within). In certain instances, the melt- blending conditions of step (iii) are applied to the mixture for at least about 180 seconds; or are applied to the mixture for a residence time ranging from at least about 180 seconds to about 1800 seconds, as well as individual values or sub-ranges contained within. In some instances, the melt-blending conditions are applied to the mixture for at least about 5 minutes. In some instances, the weight-average molecular weight of the high-density polyethylene is greater than about 315 Kg / mole, 320 Kg / mole, 330 Kg / mole, 340 Kg / mole, 350 Kg / mole, 360 Kg / mole, 370 Kg / mole, or 380 Kg / mole; or the weight-average molecular weight of the high-density polyethylene is in a range starting from about 315 Kg / mole up to an upper limit of HDPE which is determined to Mw of dis-UHMWPE. In some instances, the HDPE Mw ranges from about 315 Kg / mole to 1 Mg / mole. In some instances, the weight- average molecular weight of the high-density polyethylene is about 360 Kg / mole. In some instances, the weight-average molecular weight of the disentangled ultra-high molecular weight polyethylene is greater than about 1 Mg / mole, 2 Mg / mole, 3 Mg / mole, or 3.5 Mg / mole; or the weight-average molecular weight of the disentangled ultra-high molecular weight polyethylene is in a range from about 1 Mg / mole to about 3.5 Mg / mole, as well as individual values or sub-ranges contained within. In some instances, the weight- average molecular weight of the disentangled ultra-high molecular weight polyethylene is about 3.3 Mg / mole. 9 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTIn some instances, the disentangled ultra-high molecular weight polyethylene can have a bulk density which is in a range from about 50 to 350 g / L, as well as individual values or sub-ranges contained within. In some instances, the disentangled ultra-high molecular weight polyethylene can have a tensile strength of about 30 MPa, a tensile modulus of about 700 MPa, and / or a strain at break of about 16%. In certain instances, the disentangled ultra-high molecular weight polyethylene can have a tensile strength ranging from about 25 to 40 MPa, a tensile modulus ranging from about 650 to 750 MPa, and / or a strain at break ranging from about 10 to 20%, as well as individual values or sub-ranges contained within the aforementioned ranges. In some instances, the high-density polyethylene at the melt-blending conditions of step (iii) has a viscosity of greater than about 1200, 1250, 1300, 1350, 1400, or 1450 Pa·s; or a viscosity in a range of between about 1200 to about 1500 Pa·s, as well as individual values or sub-ranges contained within. In some instances, the viscosity about 1400 Pa·s. In some instances, the high-density polyethylene at the melt-blending conditions of step (iii) has a zero-shear viscosity of greater than about 0.250, 0.300, 0.400, 0.500, 0.600, or 1.000 M Pa·s; or a zero-shear viscosity in a range of between about 0.250 to about 1.000 M Pa·s, as well as individual values or sub-ranges contained within. In some instances, the zero-shear viscosity is about 290 K Pa·s. In some instances, the disentangled ultra-high molecular weight polyethylene at the melt-blending conditions of step (iii) has a zero-shear viscosity of greater than about 1,000, 1,500, 2,500, 3,000, 3,500, 4,000, or 4,500 MPa·s; or a zero-shear viscosity in a range of between about 1,000 to about 4,500 MPa·s, as well as individual values or sub-ranges contained within. In some instances, the viscosity is about 13,000 Pa·s. Typically, the viscosities of the high-density polyethylene and the disentangled ultra- high molecular weight polyethylene under the melt-blending conditions satisfy the dynamic viscosity ratio of the equation below: ,where of the disentangled ultra-high molecular weight polyethylene andηHDPEis the viscosity of the high-density polyethylene. In some instances, theηHDPEis10 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTinstead ηPE when a polyethylene, which is not considered to be of a high-density, is used in the methods. Where a high-density polyethylene and a disentangled ultra-high molecular weight polyethylene of appropriate properties can be selected to satisfy the relationship of the equation to provide a homogeneous blend. In such instances, as shown in Figure 3A, blending is feasible when the viscosity ratio (shown on the x-axis) between the dispersed phase (dis-UHMWPE) and the matrix (commercial HDPE) is lower than about 3.5. Without being bound by any particular theory, the non-equilibrium state of the disentangled UHMWPE provides the ease in blending of the respective polymers, where the non- equilibrium state can be identified by an increase in plateau modulus as a function of time, under isothermal conditions. As shown in the example, when attempting to blend fully entangled UHMWPE with HDPE this condition was not met and the dynamic viscosity ratio was found to be above 3.5, independent of the chosen residence time for blending under the same isothermal conditions. In some instances, the amount of disentangled ultra-high molecular weight polyethylene added in step (i) provides a concentration of about 0.1 wt.% to about 40 wt.% or about 5 wt.% to 20 wt.% of the total weight of the mixture formed, as well as individual values or sub-ranges contained within. In some instances, the amount of disentangled ultra-high molecular weight polyethylene added in step (i) produces a blend in step (iii) having a concentration of disentangled ultra-high molecular weight polyethylene about 0.1 wt.% to about 40 wt.% or about 5 wt.% to 20 wt.% of the total weight of the blend formed, as well as individual values or sub-ranges contained within. In some instances, the concentration disentangled ultra-high molecular weight polyethylene is greater than about 5.5 wt.%. In some instances, the concentration disentangled ultra-high molecular weight polyethylene is greater than about 5.5 wt.% and up to about 20 wt.% of the total weight of the blend formed. The blend formed during step (iii) is typically a homogenous blend, which is understood to be formed of single phase and does not exhibit any immiscible phases therein. In some instances, the blend has a weight-average molecular weight (Mw) in range from at least about 350 Kg / mol to about 1000 Kg / mol, as well as individual values or sub-ranges contained withing the aforementioned range. In some instances, the blend has a number- 11 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTaverage molecular weight (Mn) in range from at least about 130 Kg / mol to about 100 Kg / mol, as well as individual values or sub-ranges contained withing the aforementioned range. In some instances, the blend has a Z-average molecular weight (MZ) in range from at least about 1.25 Mg / mol to about 40 Mg / mol, as well as individual values or sub-ranges contained withing the aforementioned range. In some instances, the molecular weight of the blends, which can be expressed by the Mw (weight average molecular weight) to Mn (number average molecular weight) ratio, is in a range from about 2.5 to about 15, as well as individual values or sub-ranges contained within the aforementioned range. In some instances, the cross-over relaxation time of the blend is in a range from about 0.9 to about 20.0, as well as individual values or sub-ranges contained within the aforementioned range. In some instances, the terminal flow relaxation time of the blend is in a range from about 200 to about 18,000, as well as individual values or sub-ranges contained within the aforementioned range. In some instances, the zero-shear viscosity of the blend is in a range from about 0.5 to about 50.0, as well as individual values or sub-ranges contained within the aforementioned range. In some instances, a homogenous blend including a disentangled ultra-high molecular weight polyethylene in a high-density polyethylene matrix, wherein the composition is prepared by the method detailed above. In some other instances, a homogeneous blend is provided which includes a disentangled ultra-high molecular weight polyethylene in a high- density polyethylene matrix, where the disentangled ultra-high molecular weight polyethylene is present at a concentration ranging from greater than about 5.5 wt.% to about 20 wt.% of the total weight of the homogeneous blend. Moreover, for the blends formed according to the methods, the physical and mechanical properties would be understood to be based on the respective properties of the blend components. For example, as shown in the examples below, the molar masses (i.e., Mw, Mn, Mz) of the blend products are an intermediate value based on the values of the pure HDPE and pure dis-UH fed into the compounder, and which is dependent on the wt.% of the dis-UH present. In some instances, the average yield strength (^yield,avg) for a blend is increased by at least about 1% to 50%, as compared to the average yield strength of the polyethylene (such as HDPE) used as the matrix; individual values or sub-ranges of the aforementioned range are also disclosed. In some instances, the Young’s modulus (Eavg) for a blend is increased by at least about 12 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCT1% to 50%, as compared to the Young’s modulus of the polyethylene (such as HDPE) used as the matrix; individual values or sub-ranges of the aforementioned range are also disclosed. In some instances, the methods exclude the addition of any wax(es), such as polyethylene wax(es), more particularly low-molecular weight PE wax(es). The melt-blending conditions are such that melt-extrusion results in formation of the blend during step (iii) where the blend forms an extrudate, which can optionally be pelletized or otherwise processed into other forms, such as but not limited to, a film, pellets, panels, rods, elongated objects, hollow articles (such as pipes), spun fibers, and a powder. In some instances, the compounder used in the method is a twin-screw compounder capable of blending low bulk density and high bulk density polymers. In some instances, the compounder provides a rotation rate of about 125, 150, or 175 RPM; or a rotation rate in a range from between about 125 to about 175 RPM, as well as individual values or sub-ranges contained within. In some instances, the mixing barrel, or a part thereof, of the compounder can be placed under a vacuum. In certain instances, the mixing can be performed in the compounder under an inert atmosphere (such as nitrogen or argon). In some instances, the blends produced by the methods have mechanical properties, such as tensile modulus and / or tensile strength, which is at least about 5%, 10%, or 15% higher than the mechanical properties, such as tensile modulus and / or tensile strength, of matrix polymer (i.e., HDPE matrix) chosen. In some instances, the blends produced by the methods have mechanical properties, such as tensile modulus and / or tensile strength, which are at least about 5% to 20% higher than the mechanical properties, such as tensile modulus and / or tensile strength, of matrix polymer (i.e., HDPE matrix) chosen. The disentangled ultra-high molecular weight polyethylene and high-density polyethylene which are suitable for forming the aforementioned blends are described in detail below. a. Disentangled Ultra-High Molecular Weight Polyethylene (UHMWPE) Ultra-High Molecular Weight Polyethylene (UHMWPE) can have toughness and strength reflective of their high molar mass (typically exceeding 1,000,000 g / mol). However, the polymer chains of UHMWPE are entangled. This is due to the entropically favoured entangled state, where the greater the extent of entanglement, the higher the melt viscosity 13 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTand the more difficult the UHMWPE material is to process for commercial purposes. Various approaches have been utilized in an attempt to provide UHMWPE with reduced polymer chain entanglement. Disentanglement can be achieved by the high temperature dissolution of the polymer chains using solvents, such as decahydronaphthalene (to produce Dyneema®by DSM) of fluorocarbons (to produce Spectra®by Honeywell). On cooling, the polymer crystallizes with a lower degree of molecular friction (i.e., entanglement). Some exemplary methods are known in the art to produce disentanglement of UHMWPE. See, for example, Rastogi, S., et al., Heterogeneity in polymer melts from melting of polymer crystals. Nat Mater, 2005.4(8): p.635-41. Synthesis of low-entangled UHMWPE using supported catalytic systems is also disclosed in Ronca, et al., Polymer, 53:2897-2907 (2012). In another example, WO2015 / 121162 discloses the synthesis of UHMWPE with a reduced number of entanglements using heterogeneous Ziegler-Natta catalysts. In addition to other known disentangled UHMPWEs, further disclosed herein are other examples of disentangled ultra-high molecular weight polyethylene (UHMWPE) and methods of making thereof, as described below. For instance, the disentangled UHMWPEs formed according to the particular methods disclosed herein have demonstrated improved disentanglement, as compared with previously reported UHMWPE, such as the UHMWPE prepared using a homogeneous catalytic system as described in WO 2013 / 076733 by Sarma, et al., commercially available UHMWPE from Sigma Aldrich., disentangled UHMWPE reported in Liu, et al., Macromolecules, 49:7497-7509 (2016). In another instance, a process for disentangling a UHMWPE polymer in film form includes subjecting a starting UHMWPE polymer with a weight average molecular weight of at least 500,000 grams / mole, an elastic shear modulus determined directly after melting at 160° C. of at most 1.4 MPa, and a Mw / Mn ratio of at most 6 to a compacting process, and a stretching process under such conditions that at no point during the process the temperature of the intermediate polymer film is raised to a value above its melting point, wherein in the stretching process a force is applied onto the intermediate polymer film in a first direction and in a second direction which is perpendicular to the first direction. See US20110268951A1 which is incorporated herein in relevant part. Nevertheless, the blends of disentangled UHMWPEs and high-density polyethylene (HDPE) described herein may use any suitable known disentangled UHMWPE which satisfies the requirements needed, as discussed in further detail above. 14 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTIn certain instances, disentangled UHMWPEs disclosed herein may further include nanoparticles of the polymeric support used to synthesize the polymer. Thus, the disclosed disentangled UHMWPEs can include nanoparticles made by heating a mixture of one or more MgCl2 / alcohol adducts and one or more aluminium alkyl compounds, such as, aluminum alkyls, at a suitable temperature for a time period sufficient to form a support, as disclosed herein. Such aluminum alkyls include, but are not limited to, AlMe3, AlEt3, AlOct3, AlEt2Cl, and AlEtCl2.The aluminum alkyls are preferably not tri-isobutyl aluminum. In some instances, the disentangled UHMWPEs have a weight-average molecular weight (Mw) of at least about 1, 2, 3 million g / mol, 3.5 million g / mol, 4 million g / mol, at least 4.5 million g / mol, at least 5 million g / mol, at least 5.5 million g / mol, at least 6 million g / mol, at least 6.5 million g / mol, at least 7 million g / mol, at least 7.5 million g / mol, at least 8 million g / mol, at least 8.5 million g / mol, at least 9 million g / mol, at least 9.5 million g / mol, or at least 10 million g / mol. In some instances, the disentangled UHMWPEs have a weight-average molecular weight (Mw) in range from at least about 1 million g / mol to about 10 million g / mol, as well as individual values or sub-ranges contained withing the aforementioned range. In some instances, the disentangled UHMWPE disclosed herein has a Mw of about 3.3 million g / mol. In some instances, the disentangled UHMWPEs have a number-average molecular weight (Mn) of at least about 100, 200, or 300 Kg / mol. In some instances, the disentangled UHMWPEs have a number-average molecular weight (Mn) in range from at least about 100 Kg / mol to about 500 Kg / mol, as well as individual values or sub-ranges contained withing the aforementioned range. In some instances, the disentangled UHMWPE disclosed herein has a Mn of about 300 Kg / mol. In some instances, the disentangled UHMWPEs have a Z-average molecular weight (MZ) of at least about 75, 80, 85, 90, 95, or 100 Mg / mol. In some instances, the disentangled UHMWPEs have a number-average molecular weight (MZ) in range from at least about 75 Mg / mol to about 100 Mg / mol, as well as individual values or sub-ranges contained withing the aforementioned range. In some instances, the disentangled UHMWPE disclosed herein has a MZ of about 90 Mg / mol. The molecular weight distribution of the disentangled UHMWPE can be expressed by the Mw (weight average molecular weight) to Mn (number average molecular weight) ratio. 15 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTTypically, the disentangled UHMWPE disclosed herein has a molecular weight distribution, such as less than about 12. In some embodiments, the disentangled UHMWPE disclosed herein has a molecular weight distribution of less than 10, less than 8, less than 6, less than 4, less than 3, or less than 2. In some cases, the disentangled UHMWPE can have a molecular weight distribution which can range from about 2.0 to about 12.0, as well as individual values or sub-ranges contained within the aforementioned range. In some instances, the disentangled UHMWPE has a molecular weight distribution of about 11. The molecular weight distribution and molecular weight averages (such as Mw, Mn, Mz) of disentangled UHMWPE polymers can be determined using suitable techniques known to the skilled person. In one non-limiting example, these values may be determined in accordance with ASTM D 6474-99 at a temperature of 160°C using 1,2,4-trichlorobenzene (TCB) as a solvent. Appropriate chromatographic equipment (such as PL-GPC220 from Polymer Laboratories) including a high temperature sample preparation device (PL-SP260) may be used. The system is typically calibrated using sixteen polystyrene standards (Mw / Mn <1.1) in the molecular weight range 5×103to 8×106gram / mol. For molecular 1 × 106g / mol the method described in Talebi, et al. Macromolecules 2010; 43 (6); 2780-2788 may be used. In most instances, the disentangled UHMWPE is a homopolymer of ethylene monomers. In certain other instances, the disentangled UHMWPE is a copolymer of ethylene and one or more co-monomers that are different from ethylene. When the disentangled UHMWPE is an ethylene copolymer, each of the one or more co-monomers in the UHMWPE can be an alpha-olefin, a cyclic olefin, or a diene that is different from ethylene. The co-monomer can have between 3 and 30 carbon atoms, between 4 and 30 carbon atoms, between 5 and 30 carbon atoms, between 6 and 30 carbon atoms, between 3 and 25 carbon atoms, between 3 and 20 carbon atoms, between 3 and 15 carbon atoms, between 3 and 12 carbon atoms, between 3 and 10 carbon atoms, between 3 and 8 carbon atoms, or between 3 and 6 carbon atoms. Examples of suitable co-monomers for use with ethylene to form the disentangled UHMWPE include, but are not limited to, propene, 1-butene, 1-pentene, 1- hexene, 1-heptene, 1-octene, cyclohexene, butadiene, and 1-4 hexadiene, and a combination thereof. The total amount of the one or more co-monomers in a high molecular weight copolymer of ethylene can be up to 10 mol%, up to 8 mol%, up to 5 mol%, up to 2 mol%, up 16 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTto 1 mol%, in a range from about 0.001 mol% to 10 mol%, from about 0.01 mol% to 10 mol%, from 0.1 mol% to 10 mol%, from about 0.001 mol% to 5 mol%, from about 0.01 mol% to 5 mol%, from 0.1 mol% to 5 mol%, from about 0.001 mol% to 1 mol%, from about 0.01 mol% to 1 mol%, or from 0.1 mol% to 1 mol%. i. Disentanglement Characterization The disentangled UHMWPEs described herein have a low degree of polymer chain entanglements. The disentangled state of an UHMWPE can be evaluated by the melting and crystallization kinetics, rheological characterization, such as an increase in elastic shear modulus after melting, solid-state deformation, solid-state NMR, and / or scanning electron microscopy. (a) Melting / Crystallization Kinetics The melting / crystallization kinetics of an UHMWPE can be measured using differential scanning calorimetry (DSC). A non-limiting exemplary protocol for measuring the melting / crystallization kinetics of an UHMWPE is as follows: (a) heat the UHMWPE from an initial temperature (“Ti”), such as about 50 ̊C, to an annealing temperature (“Ta”) which is higher than polyethylene’s equilibrium temperature (about 141.5̊C), such as 160, 170, 180, or 190̊C; (equilibrium melting temperature as used herein refers to the highest melting temperature that a polymer can achieve in the unconstrained condition. Thus, is an intrinsic property of a semi-crystalline polymer) (b) anneal the UHMWPE for a fixed period of time (“ta”), such as 5, 30, 60, 180, 360, 720, or 1440 mins (however, the annealing time can be varied between 1 minute to 1800 mins or more. Any time can be selected); (c) cooling to an isothermal crystallization temperature (“Tc”), such as 120, 122, 124, 126, or 128̊C, at a suitable temperature decrease rate, such as about 10 ̊C / min; (d) isothermal crystallization at the isothermal crystallization temperature for a fixed period of time (“tc”), such as about 60, about 180, or about 300 min; (e) cooling to the initial temperature, such as about 50̊C; and (f) second heating from the initial temperature, such as about 50̊C, to the annealing temperature, such as 160, 170, 180, or 190 ̊C. The melting / crystallization kinetics plot of heat flow versus temperature is based on data acquired during step (f). Generally, a change in the intensity of one or more melting peaks with the increase of annealing time (i.e. tain step b) is indicative of the disentangled state of the UHMWPE. In contrast, melting / crystallization kinetics plot of a commercially available entangled 17 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTUHMWPE does not show this feature. Without being bound to any theories, this feature is likely caused by the entanglement formation in the entangled UHMWPE. Accordingly, the changes of the melting peaks intensities as a function of time can be used to show that UHMWPE are in a disentangled state. The disclosed route for obtaining melting kinetics can be used to differentiate entangled and disentangled state of UHMWPE polymers. In some instances, disentangled UHMWPE polymers can be deformed in solid state leading to mechanical properties of 4.0 GPa and 200 GPa for tensile strength and tensile modulus, respectively. (b) Rheological Characterization The rheological characterization of disentangled UHMWPEs can be performed by oscillatory shear measurements, creep and stress relaxation in the linear viscoelastic regime using a suitable rheometer, such as a parallel plate rheometer. The measurements are typically performed at a suitable annealing temperature, with suitable angular frequency and strain. For example, the measurements are performed in the isothermal condition above the melting temperature at about 160̊C, at a fixed angular frequency in the range between 0.001 to 600 rad / s, for example 0.01 to 100 rad / s, such as about 10 rad / s in the plateau region, and a constant strain in the linear visco-elastic range between about 0.01% to 10%, such as about 0.5%. The elastic shear modulus determined directly after melting at 160oC is one of the characterizing features of the disentangled UHMWPE. Samples should show a pronounced increase in modulus with time, confirming the achievement of a disentangled state in the polymer. Generally, a modulus buildup time increases with increasing molar mass and depending on the disentangled state increases. For an example a polymer with a molar mass greater than a million g / mol can take nearly a day to reach the fully physically entangled state. Some of the examples are shown in the listed publications. (c) Solid State-Deformation Solid-state deformation of the disentangled UHMWPEs can be performed to further characterize the disentangled nature of UHMWPE. Deformation in the solid state is strongly dependent on the entangled nature of the amorphous region, the entanglements established during the polymerization will have a strong influence in solid state processing. An 18 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTexemplary method for solid state processing is disclosed in Rastogi, et al. Macromolecules 2011, 44, 5558–5568. A general procedure for the preparation of tapes is as follows: 25 g of polymer powder is poured into a mold with a cavity of 620 mm in length and 30 mm in width and compression-molded at 130 bar for 10 min at 125oC to form a sheet. The sheet is preheated for at least 1 min and rolled with a calender (diameter rolls: 250 mm, slit distance 0.15 mm, inlet speed 0.5 m / min). The tape is immediately stretched on a roll (speed 2.5 m / min). The rolled and stretched tape is further stretched in two steps on a 50 cm long oil heated hot plate. The draw ratio is obtained by dividing specific weight (mg / m) of the sheet prior to deformation by the specific weight of the tape after stretching. A typical processing temperatures of the disentangled polymer include compression molding performed from 115 to 140oC, preferably from 120 to 135oC, even more preferably at 125oC followed by calendaring performed from 120 to 145oC, more preferably from 125 to 140oC even more preferably at 130oC and stretching is performed in two steps; the first and second stretching can be performed from 125 to 160oC, more preferably from 135 to 155oC even more preferably at 140oC. (d) Morphology of Disentangled UHMWPE The form of the disentangled UHMWPE is not particularly restricted, as long as it can be processed into blends with other polymer materials, such as high-density polyethylene (HDPE). In some instances, the disentangled UHMWPE can be in the form of particles, which are homogeneous in size and can be predominantly spherical in size. The morphology and average diameter of the polymeric particles of the disentangled UHMWPE can be determined by known methods, such as Scanning Electron Microscopy using a Carl Zeiss (Leo) 1530 VP FEG-SEM. In some instances, the disentangled UHMWPE can have a narrow particle size distribution. The aspect ratio for the spherical morphology can be in the maximum order of 2:1, in the order of 1.5:1, or in the order of 1:1 for at least 95% of the synthesized disentangled UHMWPE polymer. ii. Methods of Making Disentangled UHMWPE As noted previously, various disentangled UHMWPEs are known in the art, as well as their methods of synthesis. However, further disclosed herein are synthetic methods of 19 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTmaking disentangled UHMWPEs which overcome issues and limitations in other reported disentangled UHMWPEs. In some instances, the disentangled UHMWPEs made according to these methods are preferred over other known disentangled UHMWPEs. In the particular synthetic methods disclosed below, a support is dissolved in alcohol, and precipitates with anchoring of the activator (i.e., co-catalyst) which creates the situation when the anchored support particles are dispersed in the polymerization medium which helps in polymerization followed by crystallization – reducing the number of entanglements per chain. A useful support for the disclosed method should meet the requirement of sufficient distance between the active sites so that the growing chains do not interact significantly with each other. The interaction between the chains is reduced dramatically with the onset of crystallization. To achieve such a scenario the catalyst support should provide the possibility where ideally an active site is anchored to a single particle or during polymerization it disintegrates. A suitable support is in the nanoscale that ranges between 1 and 900 nm, between about 15 and 120 nm, for example, between 20 and 100 nm, as well as individual values or sub-ranges contained therein. The methods disclosed herein reduces the number of entanglements per chain during polymer synthesis, by judicious choice of a catalytic system, to such an extent that the polymer can be directly processed into (uniaxial drawn) tapes and (biaxial drawn) films below the polymer melting point without using a solvent. The disclosed polymerization methods make use of a heterogeneous catalytic system, which includes catalysts immobilized on a support. The heterogeneous (supported) catalytic system overcomes the challenges of the homogeneous (unsupported) synthesis, for instances eliminating the fouling seen with homogenous catalytic systems. Thus, in one embodiment, a heterogeneous catalyst solution is used, with the catalyst attached to a support rather than being distributed throughout the mixture. The disclosed methods employ a combination of substrates, catalysts and reaction conditions that allow the use of a supported catalyst (i.e., the catalytic system) formed in situ (to avoid agglomeration) and the tuning of polymerisation conditions to achieve the desired disentangled state. Generally, the methods of making the UHMWPE with reduced entanglement include the steps of: (i) heating a mixture of one or more MgCl2 / alcohol adducts and one or more 20 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTaluminium alkyl compounds at a first temperature for a time period sufficient to form a support; and (ii) mixing the support with a catalyst solution, ethylene, and optionally one or more co-monomers at a polymerization temperature and under a polymerization pressure for a time period sufficient to form the disentangled UHMWPE. Typically, in step (i), the one or more MgCl2 / alcohol adducts and one or more aluminium alkyl compounds are dissolved in a solvent and in the solution phase; in step (ii), the ethylene and optionally one or more co-monomers are in the gas phase. Optionally, the method also includes mixing MgCl2 with one or more alcohols to form one or more MgCl2 / alcohol adducts prior to step (i) and / or terminating the polymerization reaction in step (ii) using a suitable terminating agent, such as ethanol. Any protic polar solvent and coordinating solvents can be used for deactivation of the catalyst. However, in the polymerization can be terminated with the consumption of ethylene or stopping the ethylene flow. (a) Synthesis of the MgCl2 / alcohol Adduct The polymerization method may include a step of mixing MgCl2 with one or more alcohols to form one or more MgCl2 / alcohol adducts prior to the synthesis of a support and prior to the polymerization reaction. A general formula for the disclosed MgCl2 / alcohol adducts is represented by MgCl2 / (OR’)m, where m is 1 to 6, for example, 1, 2, 3, 4, 5, 6, and each occurrence of OR’ represents an alcohol. For example, when m is 2, each OR’ can be the same or different from each other. Generally, one or more alcohols were slowly added to a stirred slurry of anhydrous MgCl2in n-decane at room temperature to form a reaction mixture, Alternatively, MgCl2is slowly added to a stirred a solution of one or more alcohols at room temperature to form a reaction mixture; the reaction mixture is then heated at a suitable temperature for a period of time sufficient to form the one or more MgCl2 / alcohol adducts. The solution of the one or more alcohols can be prepared by dissolving the one or more alcohols in a suitable solvent, such as n-decane. Any apolar, non-coordinative solvent can be used. Such are any aliphatic and aromatic solvents; examples include, but are not limited to toluene, xylenes, benzene, hexane, heptane, gasoline (petrol, benzine) and kerosene. Optionally, an organic solvent, such as toluene or heptane, is added in the reaction products to form a solution of the one or more MgCl2 / alcohol adducts. 21 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTAny suitable alcohols can be used in forming the MgCl2 / alcohol adducts, such as a linear or branched aliphatic mono-alcohol having between 3 and 20 carbon atoms, between 3 and 16 carbon atoms, between 3 and 12 carbon atoms, or between 6 and 16 carbon atoms. Preferred alcohols used for making the MgCl2 / alcohol adducts, include, but are not limited to ethanol, 1-butanol, tert-butanol, 3-methyl-1-butanol, 1-pentanol, cyclohexanol, 2-methyl-1- cyclohexanol, 1-octanol, 1-pentanol, 2-ethyl-1-hexanol. In certain instances, an alcohol (for example, 76.9 mmol) is added to a stirred slurry of MgCl2 (for example, 2.44 g, 25.6 mmol) in n-decane at room temperature. The resultant mixture is heated at 140oC for 4 h with constant magnetic stirring until a clear solution is obtained, then allowed to cool to room temperature. A solvent, such as, toluene or heptane is added to the resulting solution at room temperature to give a 0.5 M MgCl2 / alcohol solution and stored under nitrogen. However, any apolar, non-coordinative solvent can be used. Such are any aliphatic and aromatic solvents. (b) Synthesis of Nanoparticle Supports Nanoparticulate solid supports are formed in-situ by heating a mixture of one or more MgCl2 / alcohol adducts and one or more aluminium alkyl compounds at a suitable temperature for a period sufficient to form a support. Suitable conditions include atmospheric pressure to 3 atm (absolute) with a temperature from about 10 to about 60oC, as well as individual values or sub-ranges contained therein. In some instances, the temperature is about 50oC. A general formula for the disclosed supports is represented by MgClx / AlyRn(OR’)m, where x is between 0 and 2; y and m range from 0 to 6, i.e.., y and m can be 0, 1, 2, 3, 4, 5 or 6;, and n is between 0 and 12, i.e., n can be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12. The support can contain an inorganic oxide support, such as silica, alumina, titania, silica-alumina, and silica-titania. However, in some other embodiments, the support does not contain an inorganic oxide support, such as silica, alumina, titania, silica-alumina, and silica-titania. Suitable aluminum alkyl compounds for use in the synthesis of the nanoparticle supports include, but are not limited to, ethylaluminium dichloride, diethylaluminium chloride, ethylaluminium sesquichloride, dimethylaluminium chloride, trimethylaluminium, triethylaluminium, tri-isobutylaluminium, trihexylaluminium, tri-n-octylaluminium, methylaluminiumoxane (MAO), hexaisobutylaluminiumoxane (HIBAO), tetra-iso- 22 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTbutylaluminiumoxane (TIBAO), and isoprenylaluminium. Preferably, the aluminum alkyl compounds used in the synthesis of the nanoparticle supports is not methylaluminiumoxane (MAO). Preferred aluminum alkyls include, but are not limited to, AlMe3, AlEt3, AlOct3, AlEt2Cl, and AlEtCl2. The aluminum alkyl in some embodiments is preferably not tri-isobutyl aluminum. Each of the MgCl2 / alcohol adduct(s) and aluminium alkyl compound(s) are dissolved in a solvent and provided in the solution phase. The solvent can be selected based on the specific MgCl2 / alcohol adducts and the aluminium alkyl compounds used in the reaction. Examples of solvents for preparing the solutions of the MgCl2 / alcohol adducts and / or the aluminium alkyl include, but are not limited to, toluene, heptane, octane, iso-octane, n- decane, varsol, and a combination thereof. The total concentration of the one or more MgCl2 / alcohol adducts in the adduct solution is in a range from about 0.01 M to about 1 M, from about 0.05 M to about 1 M, from about 0.1 M to about 1 M, from about 0.2 M to about 1 M, or from about 0.2 M to about 0.6 M, , as well as individual values or sub-ranges contained therein. In some instances, the total concentration is about 0.5 M. The term “total concentration of the one or more MgCl2 / alcohol adducts” refers to the total mole of the adducts relative to the volume of the adduct solution. The total amount of the one or more aluminium alkyl compounds in the aluminium alkyl solution depends on the total concentration of the MgCl2 / alcohol adducts. Typically, the total mole of the one or more aluminium alkyl compounds is between 1 equivalent to 10 equivalent, between 1 equivalent to 8 equivalent, between 1 equivalent to 6 equivalent, between 1 equivalent to 4 equivalent, between 1 equivalent to 3 equivalent, between 1 equivalent to 2 equivalent, or between 1 equivalent to 1.5 equivalent, as well as individual values or sub-ranges contained therein. In some instances, the total mole of the one or more aluminium alkyl compounds is about 1.2 equivalent of the total mole of the adducts. Generally, the one or more MgCl2 / alcohol adducts and one or more aluminium alkyl compounds are fed in a reactor and heated at a suitable temperature for a period of time sufficient to form the nanoparticle support. The synthesis can be performed under an inert gas environment, such as nitrogen, helium, neon, argon, krypton, xenon, and radon. For example, the inert gas used in the synthesis of the support is nitrogen. 23 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTSuitable temperatures for heating the MgCl2 / alcohol adducts and aluminium alkyl compounds to form the support are at least 0 ̊C, at least 10 ̊C, at least 20 ̊C, at least 30 ̊C, at least 40 ̊C, at least 50 ̊C, up to 100̊C, up to 90 ̊C, up to 80 ̊C, up to 70̊C, in a range from about 0̊C to about 100̊C, from about 0 ̊C to about 90 ̊C, from about 0̊C to about 80̊C, from about 0̊C to about 70̊C, from about 20 ̊C to about 100 ̊C, from about 20 ̊C to about 90 ̊C, or from about 20 ̊C to about 80 C̊, as well as individual values or sub-ranges contained therein. In some embodiments the temperature is maximally, between about 50-60oC, as well as individual values or sub-ranges contained therein. Suitable time period for heating the MgCl2 / alcohol adducts and aluminium alkyl compounds to form the support is up to 2 hours, up to 1.5 hours, up to 1 hour, at least 5 minutes, at least 10 minutes, at least 15 minutes, at least 20 hour, in a range from about 5 minutes to about 2 hours, from about 10 minutes to about 2 hours, from about 20 minutes to about 2 hours, from about 5 minutes to about 1.5 hour, from about 10 minutes to about 1.5 hours, from about 5 minutes to about 1 hour, from about 10 minutes to about 1 hour, or from about 5 minutes to about 40 minutes, as well as individual values or sub-ranges contained therein. In some instances, the suitable time period is about 5 minutes, about 30 minutes, about 1 hour, or about 2 hours. The MgCl2 / alcohol adduct and aluminium alkyl compounds can be heated under any combinations of the temperature and time period described above to form the support. Exemplary reaction conditions are as follows: 1 eq. of MgCl2 / alcohol solution 3.2 eq. of Al alkyl are added to toluene at 50oC under constant stirring. The nanoparticle support synthesis method disclosed herein preferably does not include reacting the MgCl2 / alcohol with a light petroleum (b.p 40-60oC); further, the aluminum alkyl preferably is not added to toluene as a mixture with an alcohol. (c) In-situ Synthesis of Catalytic System and Polymerization procedure The nanoparticle support obtained as a result of the reaction described in (B) is reacted with a suitable catalyst (for example, bis[N-(3-tert-butylsalicylidene)pentafluoroanilinato] titanium (IV) dichloride; however not limited to the given example) to form the final catalytic system, in the presence of ethylene and optionally one or more co-monomers, under the polymerization conditions disclosed below. Any catalyst that is able to produce linear 24 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTpolyethylene having molar mass greater than a million g / mol, and could be supported on the given supports, for example metallocenes and bisphenoxyimines having metallic centers Ti, Zr, or Hf. Preferably, the catalytic system is not pre-formed prior to the polymerization procedure, and is this distinguishable from other methods as disclosed for example, in Severn and Chadwick, Macromolecular Chemistry and Physics, 2004, 205, 1987, who do not provide disentangled UHMWPE as their support was pre-formed, resulting in significantly large particle size, in the order of mm. In the disclosed methods, the support is dissolved using alcohols and precipitated in-situ using aluminum alkyls, where the resulting product acts as a catalyst activator and support. This approach leads to the formation of nm size co- catalyst supports that helps in activating the catalyst. In some preferred embodiments, the polymerization procedure does not use an iron-, chromium-, or vanadium-based precatalyst such as bis(imino)pyridyl iron, bis(imino)pyridyl chromium, or bis(imino)pyridyl vanadium. In preferred embodiments, the catalysts used in the polymerization procedure contain halogen, such as fluorine, chlorine, bromine, or iodine. Generally, following a first step (i) of heating a mixture of one or more MgCl2 / alcohol adducts and one or more aluminium alkyl compounds to form a support, a catalytic solution is fed into the reactor and mixed with the support formed in step (i). The ethylene and optionally one or more co-monomers are typically in the gas phase, however, they dissolve in the reaction media. The catalytic solution contains one or more suitable catalysts for the polymerization reaction and can be prepared by dissolving the one or more catalysts, such as bis[N-(3-tert-butylsalicylidene) pentafluoroanilinato] titanium (IV) dichloride, in a suitable organic solvent, such as those described above, for example, toluene or heptane, or a combination thereof. In some embodiments, the catalysts are dissolved in a mixture of toluene and heptane, and the volume ratio of toluene to heptane can be in an range from 0.001 to 1000, from 0.01 to 1000, from 0.1 to 1000, from 1 to 1000, from 10 to 1000, from 20 to 1000, from 50 to 1000, from 80 to 1000, from 100 to 1000, from 0.001 to 500, from 0.01 to 500, from 0.1 to 500, from 1 to 500, from 0.001 to 100, from 0.01 to 100, from 0.1 to 100, or from 1 to 100. The total concentration of the one or more catalysts in the catalyst solution can be in a range from about 0.1 µM to about 100 µM, from about 0.5 µM to about 100 µM, from about 1 µM to about 100 µM, from about 5 µM to about 100 µM, from about 5 µM to about 90 µM, from about 5 µM to about 80 µM, from about 5 µM to about 70 µM, from 25 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTabout 5 µM to about 60 µM, from about 5 µM to about 50 µM, from about 5 µM to about 40 µM, from about 5 µM to about 25 µM, from about 10 µM to about 50 µM, or from about 10 µM to about 30 µM, such as about 15 µM. The term “total concentration of the one or more catalysts” refers to the total mole of the catalysts relative to the volume of the catalyst solution. The in-situ formation of the catalytic system and polymerization are carried out simultaneously under suitable polymerization conditions, such as at a polymerization pressure of up to 20 atm, up to 15 atm, up to 12 atm, up to 10 atm, up to 9 atm, up to 8 atm, up to 7 atm, up to 6 atm, up to 5 atm, up to 4 atm, up to 3 atm, up to 2 atm, or up to 1.5 atm, in a range from 1 atm to 20 atm, from 1 atm to 15 atm, from 1 atm to 10 atm, from 1 atm to 5 atm, from 1.2 atm to 20 atm, from 1.2 atm to 15 atm, from 1.2 atm to 10 atm, or from 1.2 atm to 5 atm, such as 1.2 atm or 9 atm; a polymerization temperature of about 0 ̊C, at least 10 ̊C, at least 20 ̊C, at least 30 ̊C, at least 40̊C, at least 50̊C, up to 100 ̊C, up to 90̊C, up to 80̊C, up to 70 ̊C, in a range from about 10 ̊C to about 100 ̊C, from about 10 ̊C to about 90 ̊C, from about 10̊C to about 80̊C, from about 10 ̊C to about 70 ̊C, from about 20 ̊C to about 100 ̊C, from about 20 ̊C to about 90 C̊, or from about 20 ̊C to about 80 ̊C; and a polymerization time period of at least 5 to about 120 mins, for example, about 10, 20, 30, 40, 50, 60, 70,80, 90, 100, 110 and 120 mins.. The polymerization conditions used during the polymer synthesis (i.e. temperature, pressure, polymerization time, solvents, etc.) are suitable for industrial scale synthesis. Exemplary polymerization conditions used in step (ii) are as follows: Table 1. Non-limiting Polymerization Reaction Conditions From To 26 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTIn some instances, the disclosed method exludes the use Fe, Cr, or V-based pre- catalysts, which do not contain halogen. Additionally, it is important that the reactant (i.e. ethylene) and the catalysts are mixed with the support simultaneously, following support formation. A typical polymerization process is described using AlEt3and MgCl2 / 2-ethyl-1-hexanol adduct as examples of aluminum alkyl and MgCl2 / alcohol adduct, although the reaction conditions can be extrapolated to other disclosed alcohols and aluminum alkyls, using the general reaction conditions shown in Table 1. This was demonstrated in the Examples (Table 2). A reactor is charged with 0.75 L of dry toluene under nitrogen stream gas and heated to 50oC under constant stirring. A solution of AlEt3 and 5 mL toluene and 0.5 M MgCl2 / 2- ethyl-1-hexanol adduct solution are added to a reactor respectively and stirred for 30 min to in-situ produce MgCl2 / EtnAl(2-ethyl-1-hexoxide)3-n activator / nanoparticle support. The activator is used herein to refer to the co-catalyst. The dissolved support MgCl2 in alcohol, reacted with aluminum alkyl forms insoluble adduct. The adduct activates the catalyst. Next, the temperature is set to the desired polymerization temperature, nitrogen gas is replaced with ethylene and a toluene solution of bis[N-(3-tert-butylsalicylidene)pentafluoroanilinato] titanium (IV) dichloride complex is injected to the reactor to start the polymerization and the ethylene pressure is quickly raised to the desired value. The chosen polymerization temperature ranges from 10oC to 70oC, preferably between 10oC to 40oC, more preferably 25oC to 40oC, results into a polymer having the desired mechanical properties. The ethylene pressure is maintained at the desired pressure by a continuous feed. After desired time, the polymerization is terminated by the addition of ethanol (10 ml) into the reactor. The polymerization procedure disclosed herein is a heterogeneous polymerization procedure, which provides significant advantages over procedures employing homogenous catalysis and procedures disclosed for example, in Huang, et al., J. Mol. Catalysis A: Chemical 260: 135-143 (2006), in which the methods disclosed therein require addition of tri- isobutyl aluminum, a compound which is preferably excluded from the methods disclosed herein, since it inactivates the catalysts used in the disclosed methods. By contrast, the disclosed methods preferably use titanium-based catalyst containing halogen (exemplified herein using bis[N-(3-tert-butylsalicylidene)pentafluoroanilinato] titanium (IV) dichloride) 27 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTand the addition of AlR3(R = CH3, CH2CH3) to the catalyst results in a catalytic system with the desired activity, resulting in superior production of PE with Mw > 4 million g / ml, compared to Mwof about 1 million g / mol (Mvabout 2-4 million g / mol) seen with reaction conditions including tri-isobutyl aluminum. Thus, tri-isobutyl aluminum is preferably not included in the polymerization reaction. Additionally, Huang et al (2006) made use of catalysts having different metal centers and the catalyst support with the co-catalyst was prepared ex-situ resulting support size in the order of 80 microns. b. High-Density Polyethylene (HDPE) The blends described herein make use of a high-density polyethylene (HDPE) matrix. HDPE is a versatile thermoplastic polymer with a wide range of applications due to its excellent combination of properties. HDPE is a linear, or branched, polymer consisting of long chains of ethylene monomers. The chemical structure contains repeating units of (-CH2-CH2-) n, where n represents an integer number of repeating units. The linear structure is understood to contribute to the high density and strength of HDPE. HDPE has a high density, as compared to other types of polyethylenes. In some instances, the density typically ranges from 0.941 g / cm³ to 0.985 g / cm³. The high density is typically attributed to its closely packed molecular structure. HDPE can be obtained from commercial sources or synthesized according to known methods. More particularly, the HDPE which can be used as a matrix in blends with disentangled UHMWPEs, discussed above, can be selected to have particular properties. In some instances, the HDPE matrix is selected to have a weight-average molecular weight of at least about 300 Kg / mole, 310 Kg / mole, 320 Kg / mole, 330 Kg / mole, 340 Kg / mole, 350 Kg / mole, 360 Kg / mole, 370 Kg / mole, 380 Kg / mole, or 390 Kg / mole. In certain instances, the HDPE matrix is selected to have a weight-average molecular weight in the range of about 300 Kg / mole to about 400 Kg / mole, or an individual value or sub-range contained within the aforementioned range. In one instance, the HDPE matrix has a weight- average molecular weight of greater than 320 Kg / mole. In another instance, the HDPE matrix has a weight-average molecular weight of about 360 or 370 Kg / mole. In some instances, the HDPE matrix is selected to have a weight-average molecular weight which is the lowest Mw that can be used in combination with a disentangled UHMWPE having an Mw of at 1 million 28 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTg / mol, or greater. In some instances, the HDPE matrix is selected to have a number-average molecular weight of at least about 100 Kg / mole, 110 Kg / mole, 120 Kg / mole, 130 Kg / mole, 140 Kg / mole, or 150 Kg / mole. In certain instances, the HDPE matrix is selected to have a weight- average molecular weight in the range of about 100 Kg / mole to about 150 Kg / mole, or an individual value or sub-range contained within the aforementioned range. In some instances, the HDPE matrix is selected to have a Z-average molecular weight of at least about 1 Mg / mole, 1.1 Mg / mole, 1.2 Mg / mole, 1.3 Mg / mole, 1.4 Mg / mole, or 1.5 Mg / mole. In certain instances, the HDPE matrix is selected to have a weight-average molecular weight in the range of about 1 Mg / mole to about 1.5 Mg / mole, or an individual value or sub-range contained within the aforementioned range. The HDPE forming the matrix can have a selected viscosity (η) at the processing conditions used during the melt-blending process described above. In some instances, during the melt-blending process, the HDPE has a viscosity of greater than about 1350, 1375, 1400, 1450 Pa·s, or greater. In some instances, during the melt-blending process, the HDPE has a viscosity in a range from of about 1350 to about 1450 Pa·s, as well as individual values or sub-ranges contained within. The HDPE forming the matrix can have a selected zero-shear viscosity (η0) at the processing conditions used during the melt-blending process described above. In some instances, during the melt-blending process, the HDPE has a zero-shear viscosity of greater than about 250, 260, 270, 280, 290 Pa·s, or greater. In some instances, during the melt- blending process, the HDPE has a viscosity in a range from of about 1350 to about 1450 Pa·s, as well as individual values or sub-ranges contained within. In some instances, recyclable polyethylenes can be used as the matrix material in the methods described. The blends resulting from the method would have retrospectively enhanced / improved mechanical properties over the chosen recycled polyethylenes obtained from waste stream. III. Methods of Using the Blends of Disentangled UHMWPE and HDPE The blends of disentangled UHMWPE and HDPE disclosed and formed according to the methods of making above can be used in the manufacture of articles and products. Such articles or products can be formed by solid-state and melt processing of the blends described, 29 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTwhere the solid-state and melt processing can include extrusion and / or injection molding of the blend in order to form the article or product. Other processing techniques known to a person skilled in the art are also contemplated herein. For example, these include, but are not limited to ram-extrusion, extrusion spinning, pultrusion, blow molding, compression molding, rotary molding (such as gas storage tanks / pressure vessels), film-casting, calendering, etc. Extrusion spinning refers to a manufacturing method that uses a spinneret to form multiple continuous filaments. When performed in the melt, this is known as melt spinning. Solid state processing refers to a manufacturing process performed at a temperature just below the crystalline melting temperature of the polymer (for practical reasons, typically solid-state processing is performed not more than 20 °C below the equilibrium melt temperature of the chosen polyethylene). An article can also be considered as a semi-finished part, that requires further processing steps to form a product (such as an implant or a machine gear). In one non-limiting instance, a method of forming an article or product can include the steps of: extruding or injection molding a blend of disentangled UHMWPE and HDPE, as described herein, to form an article or product. In some instances, the blends may be used to manufacture goods, commodity goods having the enhanced mechanical properties then the resin used in the blend having relatively low molar mass. Some examples include, but are not limited to, biaxial films, uni-axial drawn film, fiber, tapes. These can be used in several products, such as but not limited to battery separators, body armor, and vehicle armor, or for the reinforcement of any existing product, such as the reinforcement of water and oil pipes. Other applications in which the blends can be processed into useful articles or products include, without limitation, for packaging (such as bottles, containers, and bags), piping systems, membranes (such as geomembranes for landfill liners, pond liners, and canal linings), industrial components (such as tanks, chemical drums, and industrial linings), toys, any goods neading higher wear and abrasion resistance such are machinery gears, pallets (replacing wood), transport containers, sporting goods, and medical devices. In certain instances, the article or product formed from the blend of disentangled UHMWPE and HDPE, as described herein, is formed of fiber(s), or includes fiber(s) therein, of the respective blend. 30 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTThe present invention will be further understood by reference to the following non- limiting examples. Examples Example 1: Blends of Disentangled UHMWPE and HDPE Materials and Sample Preparation: High-density polyethylene was obtained from SABIC (HDPE P6006N, pipe grade) as nascent powder without any additives, having melt flow rate of 0.23 g / 10 min, apparent Mwof 0.37 x 106g / mole, and Ð of 2.9, and was used as the matrix in our blends. The low entangled “dis-entangled” UHMWPE (dis-UH) was synthesized in-house using a single site catalyst system, having an apparent Mw of 3.3 x 106g / mol, and Ð of 11.. The synthesis method is reported elsewhere

[0016] . Commercial entangled UHMWPE (eUH) was purchased from Ticona under the name of Gur 4120, having Mw of 3.2 x 106g / mol and Ð of 8.9. The dis-UH was added to HDPE matrix at different weight percentages: 1, 2, 5, 10, and 20 wt.%. The dis-UH-based blends are denoted “dBx”, where x represents the content of dis-UH in wt.%, for example, 5% of dis-UH in HDPE is denoted dB05. For comparison, eUH was also added to HDPE matrix at different weight percentages: 1, 2, 5, 10, and 20 wt.%. This dis-UH was termed “eBx”, where x represents the content of dis-UH in wt.%, for example, 5 wt.% of dis-UH in HDPE is termed dBo5. For comparison, eUH is also added to HDPE matrix at 5, 10, and 20 wt.%, and are termed “eBx”, where x represents the content of eUH in HDPE. Table 2 below shows the parameters of all polymers and their respective blends in this work, including apparent weight average molecular weight (Mw), apparent number average molecular weight (Mn), apparent Z average molecular expected weight average molecular weight (Mz) obtained by mixing rule, as well as cross-over and terminal flow relaxation times (τ0 and τtf, respectively) and zero-shear viscosity (η0). All parameters were obtained using melt-rheology in equilibrium state as explained in further detail below. 31 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTTable 2. Details of the polymers and their respective blends including different apparent molecular weights characteristics (Mw, Mn, Mz) obtained from melt-rheology, expected Mw obtained by mixing rule,, cross-over and terminal flow relaxation times (τ0 and τtf, respectively), and zero-shear viscosity (η0). Samples Molecular Weight Charac Melt-Rheology Content teristics Parameters d 6 ) 6 2 8 9 0 1 0 32 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTThe sample preparation, including blending and molding, is shown in the exemplary process of Figure 1. The nascent dis-UH powder was added to the HDPE matrix at 5 different weight percentages (1, 2, 5, 10, and 20 wt.%). The mixture of HDPE / dis-UH was then fed into a co- rotating twin-screw micro-compounder (Thermo Scientific HAAKE MiniLab 3 Micro Compounder). The compounding condition was 190oC, 150 RPM, and 5 minutes of residence time to form an extrudate, which is a blend of dis-UH and HDPE. An antioxidant additive, such as IRGANOX® 1010, can be added to the mix of the dis-UHMWPE and HDPE matrix prior to feeding into the blending instrument (compounder) or, alternatively, it can be previously mixed with the single components (HDPE and / or dis- UHMWPE) of the blend. The extrudate obtained was then pelletized and molded into disk-shape using Collin (P300S) hot compression system for rheological investigation. Pure HDPE and the blends were then molded into disks of 25 mm diameter and 0.9 mm thickness at 160oC and 1 bar, while dis-UH alone and eUH alone were molded into a disk of 35 mm diameter and 0.9 mm thickness at 160oC and 1 bar, while the dis-UH and eUH were molded into a disk of 35 mm diameter and 0.9 mm thickness at 160oC and 1 bar and then cut into three disks of 12 mm. The reduction in disk diameter of dis-UH and eUH samples, compared to those of the blends and pure HDPE were necessary to avoid rheology compliance issues. For mechanical testing, the extrudate was fed into injection molding directly at 190oC (HAAKE MiniJet Injection Molding System) to make dog-bone samples according to ASTM D-412. A Similar methods was used to obtain dog-bone samples of HDPE and eUH. Characterization Methods: Oscillatory Shear Rheology A Discovery Hybrid Rheometer (DHR - 20, TA Instrument, USA) was used to conduct small amplitude oscillatory shear (SAOS) and creep tests on the samples. The linear viscoelastic (LVE) regime was defined by performing an amplitude sweep at 160 °C and 10 rad / s. A dynamic frequency sweep was then carried out from 600 to 10-3rad / s at a strain of 0.2%, within the LVE regime, and a temperature of 160 °C. The creep tests were carried out at 160 °C for all samples, and a stress of 5 Pa was used for the pure HDPE, dB01, dB02, dB05, dB10, eb05, and eB10, and 50 Pa for dB020 and eB20, and 1300 Pa for dis-UH and eUH samples. 33 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTSmall Amplitude Oscillatory Shear (SAOS) experiments are performed three times, consecutively, within a ~ 2-day period on each dis-entangled UH based blended samples to ensure consistency of the data obtained. The results showed that the resultant curves superimpose nicely, indicating no polymer degradation within the measured timescale (data not shown). Their respective master curves built within the temperature range (160°C to 220°C) with Tref= 160 °C, and corresponding shift factors were generated (data not shown). The creep tests were performed at 160 °C for all samples, and a stress of 5 Pa was used for the pure HDPE, dB01, dB02, dB05, dB10, eB05, and eB10, and 50 Pa for dB20 and eB20, and 1300 Pa for dis-UH and eUH. Determination of Molecular Weights and Distribution Mead’s algorithm, which is integrated into the Orchestrator software (TA Instrument, USA), was used for the determination of the weight average molecular weights (Mw) and molecular weight distributions (Ð)

[0018] . This algorithm is based on the double reptation, i.e., mixing rule, developed by Tsenoglou and des Cloizeaux for well-entangled homogeneous linear polymers[19,20]. The principal Mead’s model algorithm evaluates the relaxationspectrum for a given polymer as: G(t) = GN [ F1 / 2(M, t)w(M)dM]2, where G(t) is therelaxation modulus, GNis the plateau modulus, w(M)dM is the weight fraction of materialwith molecular weights between M and M + dM and F1 / 2(M, t)= exp (-t / 2λ(M)) is the time dependent fractional stress relaxation of a monodisperse polymer following a small step strain. Here, λ(M) = K(T)Mxis the characteristic relaxation time for the monodisperse system, K(T) is a coefficient that depends on temperature, and x is an exponent typically ~3.4 for flexible polymers. The other parameters used in Mead’s model, and kept constant, to fit the data are the molecular weight between entanglements Me= 1900 g / mol, the critical molecular weight Mc= 4000 g / mol, the temperature T = 160oC, = 3.4, and the Front Factor x = 3.58 x 10-20. Nevertheless, the plateau modulus value G0is varied between 1 MPa and 2 MPa to obtain the best fit with the lowest error margin (all below 1% error) for each sample. At this stage, it is important to stress that the Mead model will give only apparent or indicative values for Mw and Ð in the case of binary blends because the short chains speed up relaxation of the long chains. Considering that Mead's model accounts for the long chains 34 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTas shorter ones21, and does not differentiate the enhanced relaxation due to short chains, discrepancy in the determination of Mw and Ð will arise. In addition, obtaining the complete relaxation spectrum for UHMWPE and the blends with high content of UHMWPE requires data collection in very low frequency region, making it extremely difficult for any molecular rheological model to capture the entire relaxation spectra14. Furthermore, using Mead’s model to fit UHMWPE and the blends with creep data is prone to a higher error margin compared to SAOS data (data now shown). This high error could arise from issues with the creep conversion to dynamic moduli (an empirical formula was usedfor the conversion22). As a result, molecular weights obtained from SAOS data only are considered. a. Determination of Zero-Shear Viscosity The zero-shear viscosity (η0) of all samples are obtained by fitting the complex viscosity (η*) spectrum, calculated from G’ and G’’ obtained from SAOS and creep as 2^^′2+ ^"2, with two models: Cross and Carreau-Yasuda model. In the viscosity η0 is extracted by fitting the low frequency ^0 − ^^^^^ ^ = ^ + ∞∞1 + ^^^^^^experimental data using the relation . Here, η∞is the viscosity at very large shear rate, η0is the zero-shear-rate viscosity, is the shear-thinning exponent, and the parameter is the inverse of a critical shear rate. The fitting parameters are listed in supporting information (Table 3). 35 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTTable 3. List of Cross model parameters that are used to obtain the zero-shear viscosity of all samples. Cross-model Parameters ^ η0 Error (±) κ n Dis-UH wt.% ↓ [Pa.s] [Pa.s] P In the Carreau-Yasuda model24, η0is extracted by fitting the entire frequency spectrum as per the following relation: ^−1^^^^^ = ^∞+ ^^0 − ^∞^^1 + ^^^^^^ ^ ^ Here, η∞ is the shear-rate viscosity, is the inverse of a critical shear rate, is the power law index, and is a parameter describing the transition between the Newtonian plateau and the thinning region. Their parameters are listed in Table 4. Comparison between η0 obtained from Cross model and Carreau-Yasuda model was obtained (data now shown). Both models provide very comparable values within the experimental error range. However, fittings from Carreau-Yasuda model have larger error margin, because its parameters are optimized through a larger experimental window as compared to the Cross model, i.e., entire versus low frequency spectrum, respectively. Thus, the analysis considers η0 values for all the studied samples obtained from Cross model, which are summarized in Table 2. Table 4. List of Carreau-Yasuda model parameters that are used to obtain the zero- shear viscosity of all samples. 36 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTCarreau- Yasuda Differential Scanning calorimetry (DSC) TA Instruments Differential scanning calorimetry DSC 2500 (TA Instruments, USA) was used to determine the melting temperature of the pure polymers and their blends. To reduce the thermal lag caused by samples, 2± 0.1 mg of each polymer sample was prepared and placed into a TZero aluminum pan and lid. The temperature was ramped from 40oC to 160oC at 10oC / min. The measurements were performed under nitrogen to reduce any thermal degradation. To measure crystallinity of the samples used for tensile testing (HDPE, dB05, and dB10), the resultant integrated melting peaks of the samples (shown in Figure 5) 37 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTare divided by the melting enthalpy of the extended chain polyethylene (290 J / g)25. The resultant values are tabulated in Table 5. Table 5. The melting enthalpy (ΔHm) and crystallinity of dis-UH / HDPE blends obtained by DSC. UHMWPE ΔHm Crystallinity Content [J / g] [%] Verios G4 XHR scanning electron microscopy (Thermo Fsicher Scientific, USA) was used to acquire images of the extrudate surfaces in pure HDPE and dB05. The extrudate strips were pelletized into disk-shape pellets of ~ 0.65 mm and ~1.4 mm in thickness and diameter, respectively, and then coated with gold to avoid electrostatic charging, improve the image resolution and conductivity of the insulating polymer. An acceleration voltage of 5 kV was used during the SEM measurement. A working distance between the sample and detector (Everhart-Thornley detector) of 8.0-8.2 mm was used. Tensile Properties The mechanical properties of pure HDPE, DB05 and DB10 were measured using a Zwick-Roell Z010 tensile machine (Zwick-Roell, Germany). The polymers were shaped into dog-bone samples and tested at room temperature (21oC) following the ASTM D412-Type D standard. The average values of tensile strength and Young’s modulus were obtained from three trials for each sample. The thermal history of the tested samples is as follows: the samples are first extruded at 190oC at 150 RPM for 5 minutes. Subsequently, the extrudate is fed into a pre-heated cylinder set at a temperature of 190oC for injection molding into dog- bone at a pressure of 700 bar for 10 seconds. For crystallization, the mold temperature is set at 60oC. The resultant dog-bone samples are kept at room temperature for 24 hours prior to the tensile testing. 38 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTResults and Discussion: Assessment of Low-entanglement State and Dispersion Efficiency: The entanglement state of the low-entangled UHMWPE (dis-UH) was assessed, as opposed to the fully entangled UHMWPE (eUH) of comparable apparent molecular weight and molecular weight distribution. The pure HDPE used for the blending in this example is also discussed here for comparison. The apparent molecular characteristics for the three materials are as provided in Table 1 above. Figure 2A shows the temporal evolution of the storage modulus, G’, for the dis-UH, eUH, and HDPE at 160oC, a fixed frequency of 10 rad / s and a strain of 0.1% (within the linear viscoelastic regime). It can be observed that upon melting, the dis-UH exhibited a lower modulus value and slower modulus buildup over time compared to eUH. Yet, the storage modulus of HDPE is the lowest among the three samples without any identifiable build-up with time. The lower storage modulus value for the HDPE, at the chosen frequency, was expected because of its low Mw, an the associated frequency spectrum. In addition, the absence of modulus build-up for the HDPE identifies its equilibrium melt-state. In contrast, the low G’ value and its slow build-up at high frequency, as opposed to the eUH of similar Mw and Ð, confirms the metastable out-of-equilibrium low entangled nature of dis-UH[16, 26]. ^^In fact, based on the rubber elasticity theory, the plateau modulus,^, is a function of ^^^ = ^^^ ! entanglement density, νe, as , with kb the Boltzmann constant and Tthe temperature

[0027] . Accordingly, lower the density of entanglement νe is, lower the modulus will ^^be, i.e.,^which will also result in lower melt viscosity, as compared to the equilibrium state

[0028] . The fast modulus build-up of the eUH was attributed to the common melt equilibration process because of the sample shaping and loading in the case of molten polymers rheology

[0029] . Finally, it is important to clarify the meaning of the term “thermal equilibration” for a given sample in the rest of the manuscript. A sample is considered thermally equilibrated when its dynamic moduli have reached a stable value. This is clearly the case for the data presented in Figure 2A. During the last three hours of the experiment, the G’ slope for dis- UH and eUH decreased to 0.6 Pa / s and 1.23 Pa / s, respectively. These slopes suggest that for 39 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTthe modulus to reach a nominal value of 2 MPa, it will require approximately 40 days and 18 days for dis-UH and eUH, respectively. Thus, both samples are considered thermally equilibrated. Here, it is important to highlight that the G’ values obtained at 10 rad / s do not ^^reflect the true^, since no minimum in G” or tanδis measured within the explored frequency window. As for the difference in G’ at 10 rad / s between dis-UH and eUH, though the molecular characteristics are very similar, they are not identical. The dis-UH has a broader molecular weight distribution Ð than eUH (11 and 10, respectively) and a slightly higher Mw (3.34 and 3.21 Mg / mol, respectively). These slight differences in molecular characteristics induce a small variation in the value of G’ at 10 rad / s, which reflects the ^^transition between the rubbery plateau and terminal flow regions rather than the true^. An investigation of the efficiency of dispersing dis-UH in HDPE via melt blending technique, as opposed to eUH, was also studied. Figure 3A shows the dispersibility phase diagram of a polymeric droplet in a matrix of another polymer. The dispersion of one phase into another is governed by two dimensionless parameters, the capillary number (Ca) and ^$ ^^%"# =2&12viscosity ratio (ηdispersed / ηmatrix). Ca is defined , where ηm is the viscosity of the matrix, rate, d is droplet diameter, and Γ12 is the interfacial tension. Here, Ca refers the competition between the hydrodynamic stress applied by the flow field that works towards breaking the droplet and the interfacial stress that preserves the spherical shape of the droplet within the matrix to minimize its surface energy30]. For a polymeric droplet to experience both deformation and breakup in a shear flow, the capillary number must exceed a critical value (Cacritical), defined by the thick black line in Figure 3A. Below this line, the droplet is subjected to deformation only. Because of the essential requirement of exceeding Cacritical, droplet breakup occurs only when Cacriticalis within its minimum value range, which in turn lies at a viscosity ratio below 3.5. Beyond 3.5, Cacritical follows a semi-vertical asymptote, exponentially raising the breakup kinetics barrier. In such a case, the interfacial stress cannot be disrupted by the hydrodynamic stress, preserving the shape of the droplet, and preventing its breakup30-32]. Therefore, the viscosity ratio must be lower than 3.5 to allow for a complete dispersion of the droplet in the 40 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTmatrix30]. In this example, the purpose was to disperse droplets in a matrix of the same chemical nature, i.e., PE. This resulted in an interfacial tension between the droplet and its matrix, Γ12, close to zero30. Accordingly, with the fact that Cacriticalbeing at its minimum value below viscosity ratio of 3.5, the capillary number Ca will always have a high value above Cacritical, guaranteeing the droplet breakup if viscosity ratio lies below 3.5. The viscosity ratio ηdispersed / ηmatrix for the two cases mimicking the real conditions experienced by both mixtures in the extruder, namely, a temperature of 190oC, a rotation speed of 150 RPM, and a residence time of 5 min was also evaluated. For determining the viscosity ratio, one needs to translate the rotation speed of 150 RPM into the average shear rate applied by the twin-screw co-rotating screw using: 22) 5 sin ^ 5^ 52,- cos ^ ^^^ = / 2,) 7 + 2,) 7 ≅. h is the depth of the channel, and B is the screw pitch34. Figure 3B shows the influence of residence time buildup of the complex viscosity ratio of dis-UH and eUH to the HDPE matrix at a frequency of 70 rad / s (the equivalent ^^ = 70 −1he average shear rate^' 150 ) >frequency for t*+), a strain of 0.2%, and a temperature of 190oC,oC that corresponds to theextrusion temperature. It shows that, within residence time of more than 2.5 hours, the dis-UH / HDPE viscosity ratio is always lower than the pivotal value of 3.5, while the viscosity ratio eUH / HDPE is always higher. Further, the shear rate applied by the extruder’s screws play a role in controlling the viscosity ratios. Thus, Figure 3C illustrates how viscosity ratios of dis-UH / HDPE and eUH / HDPE change by varying the shear rate, assuming the applicability of Cox-Merz empirical rule ^^?^ ^ = |^∗^ A ^| ?^ = Awith35. Both ratios decrease with increasing shear rates due to dis-UH / HDPE viscosity ratio reached 3.5 at a much lower rate (at 1.68 s-1) compared to eUH / HDPE (at 131 s-1). As evidence of the low- entangled state of dis-UH, after allowing both polymers to equilibrate in the melt for about 1.5 hours, viscosity ratio of dis-UH / HDPE curve shifted upwards (open blue symbols) 41 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTbecause of increase in viscosity of dis-UH due to the re-entanglement of chains, while eUH / HDPE exhibited no noticeable change (open red symbols). Yet, even after 1.5 hours in the melt, the dis-UH / HDPE ratio reached 3.5 at a shear rate much lower than eUH / HDPE. This finding demonstrates the fact that blending dis-UH droplet in HDPE matrix is expected to be more efficient than blending eUH of the same molecular characteristics (Mwand Ð). In fact, up to 5 min of oscillation at 70 rad / s, which is the residence time and shear rate used in the twin-screw extruder to prepare the blends studied here, the viscosity ratio of the dis- UH / HDPE is more than three times lower than eUH / HDPE, having the values of 1.12 and 4.04 respectively, as shown in Figure 3A. The improved dispersion of dis-UH droplets in HDPE compared to eUH can be shown by plotting the apparent weight average molecular weight (Mw) of each blend, which is measured based on the double reptation model of the linear-viscoelastic responses of the blends (will be discussed in section III-5), against its UHMW-PE wt.% fraction. Figure 4 shows the resultant increase in apparent Mw with increasing content of dis-UH and eUH. In the same figure, the expected Mw, calculated by applying the following simple mixingrule21,36:+ = B'% × +IJ*K + B'% %L>−MI / ^MIB,^DE^F'^% B,^EE^<^^' × +B,^EE^<^^', is plotted blends). In both dis-UH- and eUH-based blends, Mw is monotonically increasing up to 20 wt. %. However, dis-UH-based blends experienced a greater increase in Mwcompared to eUH-based blends. Using Mw of HDPE as a reference, adding 5, 10, and 20 wt.% of dis-UH (dB05, dB10, and dB20) increased Mwby 44%, 70%, and 164%, respectively. On the other hand, eUH-based blends experienced 1%, 14%, and 580% increase in Mw upon adding 5, 10, and 20 wt.% of eUH (eB05, eB10, eB20), respectively. Compared to dis-UH-based blends, the reduction in Mw of eUH-based blends indicates that a significant amount of the added eUH is not properly mixed within the HDPE matrix, leading to a lower Mw. Most importantly, the apparent Mw values for dis-UH / HDPE blends nicely agree with their expected Mw within maximum error of ~6%, while the apparent Mw values for all eUH / HDPE blends are substantially lower than their expected Mw by up to ~38% (see Table 42 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCT1). Thus, this finding strongly indicates success in melt-blending of the low-entangled UHMWPE in an HDPE matrix where the UHMW content can be increased up to 20 wt. %. The data shows that applying dispersion physics to a high viscosity component into a low-viscosity media is an efficient method to evaluate the blending efficiency of the polymeric materials, namely, dis-UH in HDPE. It should be noted that, besides using an average shear rate, the above rationalization involves two major assumptions: (i) it was assumed that the dominating flow field in the extrusion process is the steady continuous shear, despite the fact of the presence of a mixed flow field, i.e., shear, extensional uniaxial, extensional biaxial, (ii) it was assumed that the Cox-Merz rule is verified, where in such case the oscillatory complex viscosity, as a function of frequency, can be used instead of the steady-state viscosity, as a function of shear rate. Before going further in the discussion, the ^^ *+ = 7 −1^' 150 ) 0 >shear rate applied by the extruder on the polymer chains is N)−1slower than their respective Rouse rate , must first be excluded. ^^ −1 −1^' 150 )*+ = 70 > ≫ N)In the case of , the polymer chains may undergo chain-scission due to verify that such a scenario is not applicable in our case, definition of the Rouse time reported by Larson et al38was consider: +2= N B^ P; where Mw / Me =Z is the number of entanglements per chain. In this range of Me(1000 g / mol to 2340 g / mol)39-42must be tested, and the order of magnitude for the entanglement relaxation time for polyethylene τe ~ 1 ns43, 44, used, reported in the literature. Also considered was the fact that the mixing process starts when the dis-UH has a lower value of storage modulus, which results in a larger value of Me, i.e., Me ~ 4000 g / mol. By doing so, the Rouse rate , was found to be between the ranges between ~ 90 s-1for the pure dis-UH and ~ 40 x 103s-1for the pure HDPE. The detailed results for all the samples studied are given in Table 6 in the SI. Accordingly, the Rouse rate expected for the samples analyzed in our work is much faster than the average shear rate evaluated during the ^^ = 70 −1^' 150 ) > .mixing step, i.e.,*+43 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTTable 6. List of the evaluated Rouse relaxation rates for all the samples studied in this work. Content of RS−TUHMWPE [s-1] Differential Scanning Calorimetry (DSC) Figure 5A shows the differential scanning calorimetry (DSC) curves for pure HDPE and dis-UH in the nascent state, in addition to their respective blends. The DSC data was acquired from a temperature ranging from 40 °C to 160 °C with a ramp rate of 10 °C / min. In simple heating and cooling cycles, pure HDPE and dis-UH exhibited distinct melting temperature points at 132.5 °C and 142.7 °C, respectively. The higher melting temperature of dis-UH at 142.7 °C corresponded to the melting of the extended chain crystals (ECC) that form the majority of nascent dis-UH, while the lower Tm of pure HDPE at 132.5 °C represented the melting of folded chain crystals (FCC) having non-restricted non-crystalline region26. For further clarification, HDPE as used is also the nascent powder obtained directly from the reactor. The melting of the melt crystallized samples of the two polymers (HDPE 44 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTand dis-UH) is depicted in Figure 5A in dotted lines. The blends having different content of dis-UH exhibit only one melting temperature at approximately the same temperature as the pure HDPE, i.e., at ~132.5 °C. These results suggest the presence of a single phase in the blends rather than two immiscible phases, in which case two distinct melting temperatures are likely to be observed45, 46. Figure 5B shows the DSC curves of pure HDPE, dis-UH, dB10 and dB020 obtained upon annealing protocol at 190oC for 5 minutes followed by cooling to crystallization temperature of 128oC for 3 hours and then cooling to 40oC, followed by two consecutive heating and cooling cycles from 40oC to 160oC. The protocol of the annealing is illustrated in the inset of Figure 5B and has been discussed in depth in a previous work47. The annealing at 190oC for 5 minutes resembled a quiescent melt-mixing process. In annealing condition, dis-UH exhibited two melting points. In the proposed annealing cycle, pure dis-UH exhibits two melting points; high Tm corresponded to the crystallization that occurs on annealing at 128oC for 3hrs, and low Tmassociated with the material that crystallizes on cooling to room temperature after annealing.16The presence of the two melting points is attributed to the heterogeneity in the entangled state of the non-equilibrium polymer melt influencing the nucleation barrier and the associated crystallization rates. Unlike pure dis-UH, all blends even after annealing exhibit a single melting point that shows monotonic shift towards higher values with increasing content of dis-UH in the HDPE matrix. The monotonic shift of the single melting peak is attributed to the presence of a single entanglement state, thus suggesting homogeneous mixing of the UHMWPE in the matrix of HDPE. Scanning Electron Microscopy (SEM) Scanning electron microscopy (SEM) images of pure HDPE and dB05 were obtained at two different scales, i.e., 100 µm and 50 µm (FIG.13A-13D). The SEM images showed that a single smooth phase dominated the surface morphology for both samples. Although SEM probes only the local structure, it supported the melt-blending approach based on dis- UH afforded blends with a single homogeneous phase. The SEM images provided insight into the miscibility of UHMWPE in HDPE matrix, as reported by Li, et al.[8]where it was observed, by means of SEM, that melt blending of 5 wt.% of entangled UHMWPE in an HDPE matrix resulted in two separate phases, while solution blending of the same content of UHMWPE resulted in a single phase (data not shown). 45 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTMechanical Properties Figure 6 shows the stress-strain curve for pure HDPE, dB05, and dB10. The data was collected from three tensile tests conducted on each sample at room temperature. The average values for the maximum stress (^max), Young’s modulus (E), and the strain at break (^break) are shown in Figures 7A-C. When compared to pure HDPE, the ^max increased from 34 MPa to 44 MPa for dB05 and further to 47 MPa for dB10. Similarly, E also increased from 670MPa for pure HDPE to 834MPa for dB05 and further to 912 MPa for dB10. On the contrary, ^break decreased from 15.7% for pure HDPE to 11% for dB05 and further to 9.4% for dB10. The data showed that the incorporation of dis-UH chains into the HDPE matrix enhanced its overall mechanical characteristics. The improved mechanical properties of the blends were attributed to the components of high molecular weight chains. These components facilitated the creation of a greater number of tie molecules, which are believed to serve as stress transmitters between lamellar crystals48. The integration of UHMWPE chains into the HDPE matrix extended the average end-to-end distance, thereby enhancing the probability of forming inter-cluster links (ICL). These ICLs are essentially groups of chains in the amorphous phase that connect neighboring lamellar clusters, thereby strengthening the stress- bearing network. It is worth noting that the formation of ICLs becomes significant when molecular weights exceed 300 × 103g / mol49, which is in line with Mw range reported in this example. The formation of ICLs in the amorphous phase of the material contributed to the increased stiffness, as evidenced by the rise in E and σyield. However, this process could, in some instances, result in a decrease in ^break by reducing the material’s ductility, thereby limiting its ability to stretch without breaking10,49,50. In another perspective, it was found that the Young’s modulus values of the investigated samples (HDPE, dB05, and dB10) follow a linear trend with their crystallinity, and correlate nicely with the already reported data for a variety of linear PE25. The calculated crystallinity from DSC, and the resultant data for the Young’s modulus as a function of crystallinity, are provided in Table 7 and data not shown. 46 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTTable 7. The melting enthalpy (ΔHm) and crystallinity of dis-UH / HDPE blends obtained by DSC. UHMWPE Content ΔHm Crystallinity Fig.13E sh , , rystallinity obtained by DSC and compared with linear PE data recalled from literature. Linear Viscoelastic (LVE) Properties Figure 8A shows representative LVE responses, storage (G’) and loss (G”) moduli as a function of frequency for some of the analyzed polymers. Experimental data were acquired by a combination of small-amplitude oscillatory shear (SAOS), presented by the filled symbols at high frequency range, and creep-converted data, presented by the open symbols at low frequency range. The creep data has been converted using the Schwarzl empirical formula22. Accordingly, the terminal flow regime (G’ ~ ω2, G” ~ ω1) was reached for all the samples studied, except for the pure dis-UH and dB020, likely due to the presence of high content of ultra-high molecular weight chains. Due to the high dispersity nature of blended polymers, two relaxation times were observed. The initial relaxation time (τ0), which corresponded to the cross-over relaxation rate that is dominated by the short-chain population, and terminal flow relaxation time (τtf), corresponding to the relaxation rate of the whole polymer network at terminal flow, which is controlled by the long chain population in the polymers was extracted by extrapolating two straight lines having the slopes of G’ and G’’ at terminal flow (i.e., slopes of 2 and 1, respectively), the point of intersection of these two lines corresponds to τtf. In addition, Figure 8A shows the best-fit iteration of the Mead model for the representative data. The Mead model fitting was performed 2 to 3 times on the data of dis-UH / HDPE blends and plotted with the SAOS data in the SI (data not shown). The data showed that all the three duplicates gave a good fit for the experimental data. This 47 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTwas despite the fact of showing contrasted errors, probably because of the missing data at high frequency. Accordingly, it was decided to consider the fit parameters for the duplicate with the least error. A summary of the obtained relaxation times and the molecular characteristics extracted from the Mead fit is shown in Table 2 above. Figure 8B shows the complex viscosity of all the samples studied as a function of angular frequency. The complex viscosity was calculated based on both the SAOS and the creep converted data, as: U^′ 2 + ^′ ′ 2^∗ =^zero-shear-viscosity η0was data using the Cross mode23. . The η0 values for all the studied samples are summarized in Table 2 above. From the data presented in Figures 8A-B and Table 2, it was evident that incorporating more content of dis-UH (long chain population) into the HDPE matrix (short chain population), resulted in the slowing down of the blend dynamics. The initial relaxation time τ0was faster for the pure HDPE (τ0= 0.89 s) as compared to the pure dis-UH (τ0= 2016 s), and it slowed down from τ0 = 0.94 s for the dB01 to τ0 = 17.6 s for the dB020. Moreover, the slowing down of the dynamics was more prominent for the terminal flow relaxation time τtf as a function of dis-UH content. In fact, τtf increased from τtf = 44 s for the pure HDPE to 16.7 x 103s for the dB10. It was noted that τtfwas not measured for the pure dis-UH and the dB020 due to the long time required to capture the relaxation of a such high content of ultra- high-molecular-weight chains. In addition to the slow dynamics, incorporating higher fractions of dis-UH in the HDPE matrix resulted in a virtual increase in the complex viscosity (η*), and specifically the zero-shear viscosity (η0), as shown in Figure 8B. Thus, increased monotonically from η0Blend 1%= 0.62 MPa·s to η0Blend 20%= 39 MPa·s , the η0 of the pure HDPE and dis-UH are the lower (η0HDPE= 0.46 MPa·s) and higher (η0dis-UH= 1.7 Gpa.s) limit, respectively. Furthermore, the Mw captured by the Mead model was in line with the slowing down of the dynamics and the increase of the zero-shear-viscosity. Mwincreased from MwBlend 1%= 401 Kg / mol to MwBlend 20%= 0.4 x 106g / mol, while the of the pure 48 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTWIBJ*KHDPE and dis-UH represented the lower ( = 0.37 x 106g / mol) and the higher W%BL>−MI( = 3.3 x 106g / mol) extremes, respectively. The slowdown of the dynamics and the increase of the zero-shear viscosity, together with the monotonic increase of the weight average molecular weight highlights the efficiency and ease of blending the dis-UH in HDPE matrix, as opposed to eUH. On the other hand, it strongly evidences a higher dispersion fraction of the dis-UH chains in the HDPE matrix when increasing the initial dis-UH content. The above observations comply qualitatively with the “Tube Dilation” concept18,51- 53where the constraint release (CR) mechanism in polydisperse polymer, or blends, plays a role in influencing the chains’ dynamics

[0042] . Figures 9A and 9B show a schematic representation of the action of the constraint release in the case of a test long and short chain, respectively. In fact, the common picture of the tube dilation concerns a test long chain in a mixture of short and long chains, as shown in Figure 9A. In this case, the virtual tube in which the long chains are confined will enlarge due to the fast relaxation of the short chains in the mixture, i.e., fat tube. However, in this case, the test short chains of the pure HDPE are constrained by the neighboring long chains of dis-UH, as shown in Figure 9B. Due to their extremely long relaxation times, the long chains are seen by the tested short chains as permanent obstacles

[0019] . Due to these obstacles, the tested short chains will be forced to reptate within a skinny virtual tube, thus, slowing down the relaxation rate of the blends compared to pure HDPE. Further quantitative evidence for the blends’ homogeneity by testing the scaling law relating their η0to Mw, (i.e., η0∝ Mw) is provided below. Scaling Relation of the Zero-shear Viscosity (η0) with MwFigure 10A provides the η0of all polymers discussed in this example (pure and blends) as a function of Mw, together with monodisperse and polydisperse PE reported in literature, as indicated in the figure’s legend. The data for the pure polymers and blends fall within the previously reported data. However, it can be observed that the data points are divided into three zones that each can be fitted with a power law with a straight line of different slope, as shown in Figure 10B. The first zone is composed of the three lowest Mw 49 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTdata points, namely pure HDPE, dB01 and dB02, with Mwof 0.37 x 106, 0.4 x 106, and 0.44 x 106g / mol, respectively. These data points can be fitted with a power law of ηo Mw3.62. In fact, 3.4 is the expected scaling exponent for the scaling relation of the zero-shear-viscosity as a function of Mw for linear entangled polymers above the critical molecular weight , i.e., ηoMw3,4. Yet, experimentally, one may find a larger window of the scaling exponent ranging from 3.36 to 3.64 as a function of the chain polydispersity12, 55. Vega, et al. and Aguilar, et al. observed a scaling relation with a power exponent of 3.4 in linear polydisperse PE, with Ð ranging from 2 to 13.3, while Stadler, et al. and Szanto, et al. reported a power of 3.6, with Ð ranging from 1 to 160012, 55-57. Moreover, at sufficiently high molecular weight, the effective slope of 3.4 ~ 3.6 deviates to a lower value of 3, as reported by Colby, et al. and Milner, et al.58,59. Thus, the second zone is composed of the three highest Mwdata points, namely dB10, dB020, and pure dis-UH, having Mwof 0.62 x 106, 0.97 x 106, and 3.3 x 106g / mole, respectively. These data points follow a power law of η0 ~ Mw3.03. Interestingly, the scaling relations found for the extreme Mwdata points fall within the reported values, where the exponent transitions from 3.6 to 3.0 as the molecular weight increases beyond reptation molecular weight (Mr), which typically ranges from 442 to 800 x103g / mole12. The third zone, on the other hand, is composed of the data points of medium Mw, i.e., dB02 (englobed by zone 1 and zone 3) and dB05 with Mwof 0.44 x106and 0.53 x106g / mole, respectively. This group, which represents the transition zone between the first group (exponent of 3.62) and second group (exponent of 3.03), exhibits a sharp increase in η0. These data points can be fitted with a power law of η0 ~ Mw8.95. This interesting jump in η0 and power exponent was not expected, and it does not allow for accurate measurement of which corresponds to the transition point between the power exponent of 3.6 and 3. Subsequent studies investigated the origin of the sudden jump in viscosity observed in the data above, which alters the scaling law; a similar increase in η0 was previously reported in linear entangled polydisperse polymers and blends12,55,59,59. Two possible sources have been discussed: (i) the presence of chain branching, and (ii) the high dispersity of the polymers. Hatzikiriakos, et al., showed that the influence of chain branching and dispersity on the activation energy (Ea) and Van Gurp plots is quite similar

[0048] , i.e., with increasing chain branching or dispersity, the activation energy (Ea) increases while the area under the 50 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTcurve of Van Gurp plots decreases. However, the chain branching should not be held accountable for the dramatic increase in viscosity observed in the data for the following reasons: (i) the activation energy of our base matrix (pure HDPE), dB10, dB020, and dis-UH were found to be 35, 37, 39, 36 and 20 kJ / mole, respectively (Figure 11). The corresponding master curves and shift factors are were also generated (data not shown). These values lie within the previously reported Ea values for linear PE, i.e., from 20 to 40 kJ / mole12. Moreover, the presence of chain branching in PE can increase Eaup to 88 kJ / mole, which is far higher than the values obtained in these blends60; (ii)13C HT-NMR spectrum measured for dis-UH, in prior work, revealed a single carbon resonance peak at 29.4 ppm, indicating the absence of chain branching and the high linearity of the synthesized dis-UH61. Therefore, the effect of the increase in dispersity of these blends, namely Mw / Mn and Mz / Mw, on the scaling law of as a function of apparent Mw was also examined, as discussed below. Figure shows the characteristic molecular weights (Mw, Mn, and Mz) as a function of dis-UH content in the HDPE matrix. It can be observed that, while Mwincreases almost monotonically, a significant jump in Mz can be observed at the transition point from dB01 to dB05, hence, increasing the value of Mz / Mw. A closer look at the data suggests that the initial increase in polydispersity (Mw / Mn), up to 2 wt.% of dis-UH, is mainly influenced by increase in Mw, whereas from 2 to 10 wt% the increase in polydispersity is caused mainly by the drop in Mn. Though the gradual increase in Mwwith the addition of dis-UH in HDPE matrix is anticipated, the drop in Mnof the blend is unexpected. The uncertainty in the measured Mn of the blends most probably arises from the difficulty to access the low-frequency region of the spectrum, which consequently forces the Mead’s model to compensate for the missing region in the frequency spectrum by adding short chains to adjust the fitting of the curves, leading to a reduced Mn. Thus, the drop in Mn recalls the limitation of Mead’s model in capturing the real dynamics involved in binary blends (refer to section II-2b). Note also that this unexpected decrease in Mn has been reported for in-situ reactor-blended PE12. Nevertheless, one can treat the η0jump observed in the transition point, from dB02 to dB05, by correcting for polydispersity. Figure 12B reproduces the raw data of η0 as a function of Mwfor the blends as reported in Figures 10A-B, together with the dispersity- 51 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTbased-correction of the same data, as discussed below. The high dispersity of the blends was corrected by considering the same correction factor used by Szántó, et al.

[0013] for reactor blended PE, as follows: 0.^FY<<^F'^% LZL^^[ W 12 W −0.68Y< B ]0 = ^0 PW Q PW Q^ B. ^F0Y<<^F'^%highlights two different regimes for the scaling law. A clear transition between a power law exponent of 3.6 to 3.0 was observed. This result complied with the power law exponent expected for linear polydisperse entangled polymer melts, i.e., 3.6, and it’s decreased at extremely high molecular weights, i.e., 3, therefore confirming the homogenous blending of up to 20% of low entangle ultra-high-molecular-weight in an HDPE matrix. In addition, it is useful to evaluate the intersection molecular weight of the two regimes, which corresponds the reptation molecular weight (Mr)60. In this instance, Mr= 0.48 x 106g / mol, which is in terms of the number of entanglement segments Mr / Me 287, with Me = 1670 g / mol was taken as an average value for range reported in the literature, i.e., from 1000 to 2340 g / mol39-42. The agreement between the experimental, found in this work, and theoretical number of entanglement segments that corresponded to Mrof linear entangled polymers supported the blending route and the enhanced dispersion of dis-UH, as compared to eUH. Conclusion The dispersibility of dis-UH in HDPE matrix at the melt-blending condition (i.e., 190oC, 5 minutes residence time, and 150 RPM) was assessed, and compared to eUH in the same HDPE matrix. The results showed that dis-UH / HDPE exhibited a viscosity ratio more than 3 times lower than eUH / HDPE (1.12 and 4.04, respectively). The reduced viscosity ratio (below 3.5) suggests higher compatibility of dispersing dis-UH in HDPE matrix as opposed to eUH, since Cacriticalfor dis-UH / HDPE is at minimum, while Cacriticalfor eUH / HDPE is following a semi-vertical asymptote above viscosity ratio of 3.5. 52 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTThe blends of dis-UH / HDPE with weight fraction of dis-UH up to 20 wt.% were characterized to investigate the homogeneity of the blends. DSC results showed that blends containing different fractions of dis-UH displayed a single melting temperature at approximately the same temperature as pure HDPE, around 132.5°C. This suggested the presence of a single phase in the blends, rather than two immiscible phases. Additionally, SEM images of the extrudate surface for pure HDPE and dB05 were obtained. Unlike SEM images of melt-blended eUH / HDPE from literature[8], the SEM images revealed a smooth surface of dB05 and presence of single phase. The impact of adding dis-UH in HDPE matrix on the mechanical properties was investigated by performing tensile tests on the dog-bone samples of pure HDPE, dB05, and dB10 at room temperature. The results showed that by incorporating up to 10 wt.% of dis-UH in HDPE matrix, the average maximum stress (^maximum) and Young’s modulus (E’) increased by 37 % and 38 %, respectively, while the average strain at break (^break) was reduced from 15.9% to 9.6%. The overall improvement in mechanical properties was attributed to the presence of UHMW chains that facilitated the creation of a greater number of tie molecules, hence, increasing the probability of formation of inter-clusters links (ICL). The LVE response of pure HDPE, dis-UH, and their blends was investigated by performing SAOS, creep, and time-temperature superposition (TTS). The results showed that with increasing wt.% content of dis-UH in HDPE matrix, the cross-over and terminal flow relaxation rates were slowed down, with the latter being more substantial. Coherently, the extracted apparent Mw from Mead fits and η0 obtained via cross-model displayed a monotonic rise with increasing fraction of dis-UH in HDPE. Then, the scaling law of η0α Mnwas investigated to obtain the reptation molecular weight (Mr). Overall, η0 values for all blends lie within the previously reported range of linear entangled PE. However, an intriguing jump in η0 was observed above MwdB02= 0.44 x106g / mol, which could be attributed to either chain branching or high dispersity of the polymers. Our investigation showed that the horizontal flow activation energy (Ea) of all blends obtained from TTS fell within the values of linear entangle PE, i.e., 20 ≤ Ea ≤ 40 kJ / mol, indicating the absence of chain branching. On contrary, the blends exhibited an increase in Mz accompanied by a substantial drop in Mnabove MwdB02= 0.44 x106g / mol. This finding suggested that the increase in Mw / Mn and Mz / Mw was overestimating η0, leading to a mismatch between the well-known 53 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCTtwo linear-dependency zones, e.i. η0α M3.6and η0α M3. Thus, a correction factor was used to consider the high dispersity issue, which in turn resulted in a smooth transition between exponent 3.6 to 3. Then, Mrwas found accordingly at the transition point between the two linear dependencies to be ~ 0.48 x 106g / mole, leading to number of entanglement segments Mr / Me287. The agreement in the number of entanglement segments between the experimental (Mr / Me ≅ 287, this work), and theoretical (Mr / Me = 300, reported by Colby, et. al

[0055] and Milner, et. al59) strongly indicated the success of the blending route and the enhanced dispersion of dis-UH in an HDPE matrix discussed here. References made in the above disclosure, as denoted by superscripted number, refer to the following: 1. LOHSE, Applied Polymer Science: 21st Century 2000, 73. 2. Sobieraj, et al. Journal of the mechanical behavior of biomedical materials 2009, 2 (5), 433-443. 3. van der Werff, et al. In Advanced Fibrous Composite Materials for Ballistic Protection, Chen, X., Ed. Woodhead Publishing: 2016; pp 71-107. 4. Ke, et al. Composites Part B: Engineering 2012, 43 (3), 1425-1432. 5. Rane, et al. In Synthesis of Inorganic Nanomaterials, Mohan Bhagyaraj, S.; Oluwafemi, O. S.; Kalarikkal, N.; Thomas, S., Eds. Woodhead Publishing: 2018; pp 121- 139. 6. Tinçer, et al. Polymer Engineering & Science 1993, 33 (19), 1243-1250. 7. Boscoletto, et al. European Polymer Journal 1997, 33 (1), 97-105. 8. Li, et al. Journal of Macromolecular Science, Part B 2011, 50 (7), 1249-1259. 9. Kurek, et al. Macromol Rapid Commun 2010, 31 (15), 1359-63. 10. Hofmann, et al. Macromolecules 2017, 50 (20), 8129-8139. 11. Zhong, et al. Polymer 2018, 140, 107-116. 12. Szántó, et al. Journal of Rheology 2019, 63 (5), 773-784. 13. Ferreira, et al. eXPRESS Polymer Letters 2017. 14. Ianniello, et al.Journal of Rheology 2022, 66 (5), 1079-1088. 15. AlMaadeed, et al. Arabian Journal of Chemistry 2015, 8 (3), 388-399. 16. Rastogi, et al. Nat Mater 2005, 4 (8), 635-41. 17. Chaudhuri, et al. Journal of Rheology 2020, 64 (1), 1-12. 18. Mead, et al. Journal of Rheology 1996, 40 (4), 633-661. 19. Des EPL (Europhysics Letters) 1988, 5 (5), 437. 20. Tsenoglou, et al. Abstracts of Papers of the American Chemical Society, AMER CHEMICAL SOC 115516TH ST, NW, WASHINGTON, DC 20036: 1987; pp 219-POLY. 21. Mead, et al. Journal of Rheology 1996, 40 (4), 633-661. 22. Struik, et al. Rheologica Acta 1969, 8 (2), 134-141. 23. Cross, et al. J. Colloid Inteerface Sci.1965, 20, 417-437. 54 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCT24. Yasuda, K. Investigation of the analogies between viscometric and linear viscoelastic properties of polystyrene fluids. Massachusetts Institute of Technology, 1979. 25. Humbert, et al. Polymer 2011, 52 (21), 4899-4909. 26. Lippits, et al. Macromolecules 2006, 39 (26), 8882-8885. 27. Colby, et al. New-York: Oxford University 2003, 274-281. 28. Chaudhuri, et al. Polymer Engineering & Science 2019, 59 (4), 821-829. 29. Reiter, G., The memorizing capacity of polymers. The Journal of Chemical Physics 2020, 152 (15). 30. Grace, et al. Chemical Engineering Communications 1982, 14, 225-277. 31. Utracki, et al. Polymer blends handbook. Kluwer academic publishers Dordrecht: 2002; Vol.1. 32. Starý, et al. In Characterization of Polymer Blends, 2014; pp 93-132. 33. Charfeddine, I.; Majesté, J. c.; Carrot, C.; Lhost, O., Surface tension and interfacial tension of polyolefins and polyolefin blends. Journal of Applied Polymer Science 2022, 139 (14), 51885. 34. Vergnes, et al. Polymers (Basel) 2021, 13 (2). 35. Cox, et al. Journal of Polymer Science 1958, 28 (118), 619-622. 36. Wong, et al. Polymer Testing 2002, 21 (6), 691-696. 37. Kida, T et al. Polymers 2021, 13 (23), 4222. 38. Larson, et al. Journal of Rheology 2003, 47 (3), 809-818. 39. Rubinstein, et al. Polymer physics. Oxford university press New York: 2003; Vol.23. 40. Fetters, et al. Macromolecules 1999, 32 (20), 6847-6851. 41. Litvinov, et al. Macromolecules 2013, 46 (2), 541-547.42. Vega, J. F.; Aguilar, M.; Martın ́ez-Salazar, J., Model linear metallocene-catalyzedpolyolefins: Melt rheological behavior and molecular dynamics. Journal of Rheology 2003, 47 (6), 1505-1521. 43. Szántó, et al. Journal of Rheology 2017, 61 (5), 1023-1033. 44. Ramos, et al. Macromolecules 2008, 41 (8), 2959-2962. 45. Delgadillo‐Velázquez, et al. Journal of Polymer Science Part B: Polymer Physics 2008, 46 (16), 1669-1683. 46. Oliveira, A. D.; Freitas, D. M.; Araújo, J. P.; Cavalcanti, S. N.; Câmara, D. S.; Agrawal, et al. Materials Research Innovations 2020, 24 (5), 289-294. 47. Liu, et al. Macromolecules 2016, 49 (19), 7497-7509. 48. Huang, et al. Journal of Polymer Science Part B: Polymer Physics 1991, 29 (1), 129- 137. 49. Kida, T et al. Polymer 2021, 218, 123526. 50. Lindqvist, et al. Journal of Polymers and the Environment 2019, 27, 386-394. 51. Marrucci, et al. Journal of Polymer Science: Polymer Physics Edition 1985, 23 (1), 159-177. 52. Ball, et al. American Chemical Society 1989. 53. van Ruymbeke, et al. Journal of Non-Newtonian Fluid Mechanics 2005, 128 (1), 7- 22. 54. Graham, et al. The Society of Rheology 2003. 55. Vega, et al. Rheologica Acta 2011, 51 (1), 81-87. 56. Stadler, et al. Rheologica Acta 2005, 45 (5), 755-764. 57. Aguilar, et al. Polymer 2001. 55 45710250.1 Attorney Ref. #:KAUST 2023-130-02 PCT58. Colby, et al. Macromolecules 1987. 59. Milner, et al. Physical Review Letters 1998, 81 (3), 725-728. 60. Hatzikiriakos, et al. Polymer Engineering & Science 2000, 40 (11), 2279-2287. 61. Gote, et al. Macromolecules 2023, 56 (1), 361-378. 62. Vega, et al. Journal of Rheology 2004, 48 (3), 663-678. 63. Colby, et al. Macromolecules 1987, 20 (9), 2226-2237. 64. Milner, et al. Physical Review Letters 1998, 81 (3), 725. 65. Hannecart, et al. Polymers 2023, 15 (6), 1569. Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of skill in the art to which the disclosed invention belongs. Publications cited herein and the materials for which they are cited are specifically incorporated by reference. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims. 56 45710250.1

Claims

We claim:

1. A method for preparing a blend comprising a disentangled ultra-high molecular weight polyethylene in a high-density polyethylene matrix, the method comprising the steps of: (i) mixing a high-density polyethylene and a disentangled ultra-high molecular weight polyethylene; (ii) placing the mixture of step (i) into a compounder; and (iii) exposing the mixture to melt-blending conditions to form the blend comprising the disentangled ultra-high molecular weight polyethylene in the high-density polyethylene matrix; wherein viscosity of the disentangled ultra-high molecular weight polyethylene and viscosity of the high-density polyethylene at the melt- blending conditions have a dynamic viscosity ratio satisfying equation (1): ηUH / ηHDPE≤ 3.5 (1)whereηUHis the viscosity of the disentangled ultra-high molecular weightpolyethylene andηHDPEis the viscosity of the high-density polyethylene.

2. The method of claim 1, wherein step (i) further comprises adding an antioxidant additive.

3. The method of claim 2, wherein the antioxidant additive is present at concentration of at least about 1 to 1.5 wt.% of the mixture formed during step (i).

4. The method of any one of claims 1-3, wherein the antioxidant additive is an IRGANOX® additive.

5. The method of any one of claims 1-4, wherein the melt-blending conditions comprise heating the mixture to a temperature of at least about 100 °C, 125 °C, 150 °C, 175 °C, 180 °C, 185 °C, 190 °C, 195 °C, 200 °C,45710250.1225 °C, 250 °C, 275 °C, 195 or 300 °C; or to a temperature in a range of between about 100 °C to about 300 °C.

6. The method of any one of claims 1-5, wherein the melt-blending conditions comprise applying a shear deformation of at least about 10 rad / s, at least about 20 rad / s, at least about 30 rad / s, at least about 40 rad / s, at least about 50 rad / s, at least about 60 rad / s, at least about 70 rad / s, at least about 80 rad / s, or at least about 90 rad / s; or applying a shear deformation in a range from about 10 rad / s to about 90 rad / s.

7. The method of any one of claims 1-6, wherein the melt-blending conditions are applied to the mixture for at least about 180 seconds; or are applied to the mixture for a residence time ranging from at least about 180 seconds to about 1800 seconds.

8. The method of any one of claims 1-7, wherein the weight-average molecular weight of the high-density polyethylene is greater than about 315 Kg / mole, 320 Kg / mole, 330 Kg / mole, 340 Kg / mole, 350 Kg / mole, 360 Kg / mole, 370 Kg / mole, or 380 Kg / mole; or the weight-average molecular weight of the high-density polyethylene is in a range from about 315 Kg / mole to about 380 Kg / mole.

9. The method of any one of claims 1-8, wherein the weight-average molecular weight of the disentangled ultra-high molecular weight polyethylene is greater than about 1 Mg / mole, 2 Mg / mole, 3 Mg / mole, or 3.5 Mg / mole; or the weight-average molecular weight of the disentangled ultra- high molecular weight polyethylene is in a range from about 1 Mg / mole to about 3.5 Mg / mole.

10. The method of any one of claims 1-9, wherein the high-density polyethylene at the melt-blending conditions of step (iii) has a viscosity of greater than about 1200, 1250, 1300, 1350, 1400, or 1450 Pa·s; or a viscosity in a range of between about 1200 to about 1500 Pa·s.

11. The method of any one of claims 1-10, wherein the high-density polyethylene at the melt-blending conditions of step (iii) has a zero-shear viscosity of greater than about 0.250, 0.300, 0.400, 0.500, 0.600, or 1.000 M45710250.1Pa·s; or a zero-shear viscosity in a range of between about 0.250 to about 1.000 M Pa·s.

12. The method of any one of claims 1-11, wherein the disentangled ultra-high molecular weight polyethylene at the melt-blending conditions of step (iii) has a viscosity of greater than about 1,000, 1,500, 2,500, 3,000, 3,500, 4,000, or 4,500 MPa·s; or a viscosity in a range of between about 1,000 to about 4,500 MPa·s.

13. The method of any one of claims 1-11, wherein the disentangled ultra-high molecular weight polyethylene is present at a concentration of about 0.1 wt.% to about 20 wt.% or about 5 wt.% to about 20 wt.% of the total weight of the blend formed.

14. The method of any one of claims 1-13, wherein the blend formed during step (iii) forms an extrudate which is optionally pelletized.

15. The method of any one of claims 1-14, wherein the compounder is a twin-screw compounder.

16. A homogenous blend comprising a disentangled ultra-high molecular weight polyethylene in a high-density polyethylene matrix, wherein the composition is prepared by the method of any one of claims 1-15.

17. A homogeneous blend comprising a disentangled ultra-high molecular weight polyethylene in a high-density polyethylene matrix wherein the disentangled ultra-high molecular weight polyethylene is present at a concentration ranging from greater than about 5.5 wt.% to about 20 wt.% of the total weight of the blend.

18. The homogenous blend of any one of claims 16 or 17, wherein the homogenous blend forms melt-spun fibers.

19. An article or product formed by solid-state or melt processing of the homogeneous blend of any one of claims 16 -18.

20. The article or product of claim 19, wherein the solid-state or melt processing comprises extrusion and / or injection molding of the homogeneous blend to form the article or product.45710250.1

Images