Method to modify polymer recyclates and compositions made therefrom

Abstract

Provided are modified polymer recyclate compositions and articles comprising such compositions. A polymer recyclate is subjected to a crosslinking process to produce a modified polymer recyclate composition having an increased molecular weight. Disclosed polymer recyclate compositions and articles comprising such modified polymer recyclate compositions demonstrate one or more improved mechanical properties compared to corresponding unmodified polymer recyclate compositions.

Description

METHOD TO MODIFY POLYMER RECYCLATES AND COMPOSITIONS MADE THEREFROMFIELD OF THE INVENTION

[0001] The present disclosure relates to modified polymer recyclate compositions having one or more improved mechanical properties and articles comprising such modified polymer recyclate compositions.BACKGROUND OF THE INVENTION

[0002] There has been much research and development to improve the processability of postconsumer recycle (PCR) resins, either alone or as a blend component with virgin polymers. Likewise, there has also been much effort by industry to develop end-use applications that incorporate PCR resins and have quality and / or performance similar or equal to corresponding end-use applications fabricated from virgin polymers. Existing and new environmental regulations provide continued motivation to develop suitable commercial uses of PCR resins while reducing the amount of waste plastics landfill. Successful development of these commercial pathways will create demand for products incorporating PCR resins.

[0003] One of the primary concerns associated with post-consumer recycled (PCR) materials is the decrease in molecular weight (MW) and increase in molecular weight distribution (MWD) that occurs with each round of recycling. As the chain length of the polymers is reduced, the physical properties of the final product can be adversely affected, including reduced mechanical elongation, strength, toughness, environmental stress crack resistance (ESCR), and barrier properties. While the addition of antioxidants can help mitigate chain cleavage, it is impossible to prevent it completely due to the random nature of cleavage points and the low loading of antioxidants throughout the polymer matrix. This reduction in chain length limits the number of times that PCR materials can be recycled and contributes to the poor performance of products made with these materials.

[0004] There is a need to provide products incorporating recycled polymers and / or increased amounts of recycled polymers. The utility of recycled polymers might be expanded if the inherent decrease in molecular weight could be mitigated or otherwise controlled to produce polymer recyclates having increase molecular weights. Ideally, such products could be produced with commonly used equipment and familiar techniques to provide utility in a broad range of end-use applications.SUMMARY OF THE INVENTION

[0005] The present disclosure relates to modified polymer recyclate compositions, wherein such modified polymer recyclate compositions have a higher weight average molecular weightthan their corresponding unmodified precursors. The unmodified precursors, each a polymer recyclate feed composition, comprise one or more polymer recy elates and optionally one or more virgin polymers, useful as tie layers in multilayer films.

[0006] A method for production polymer recyclate product comprises subjecting a polymer recyclate feed composition to a crosslinking process to produce a modified polymer recyclate product, wherein the polymer recyclate feed composition has a first weight average molecular weight (Mwi), the modified polymer recyclate product has a second weight average molecular weight (MW2), and weight MW2 is greater than Mwi. The modified polymer recyclate product has one or more improved mechanical properties compared to a corresponding unmodified polymer recyclate composition.

[0007] In some embodiments, the crosslinking process comprises a chemical crosslinking process, a moisture-cure crosslinking process, a radiation crosslinking process, or a photocrosslinking process.

[0008] In some embodiments, a modified polymer recyclate product corresponds to each of the foregoing crosslinking processes.

[0009] In some embodiments, a recyclate product comprises one or more of the foregoing modified polymer recyclate products.

[0010] In some embodiments, an article is formed comprising the recyclate product.

[0011] The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter, which form the subject matter of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiments disclosed may be readily utilized as a basis for modifying or designing other film structures and / or processes for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its structure and method of manufacture, together with further objects and advantages will be better understood from the following description.DETAITED DESCRIPTION OF THE INVENTION

[0012] Illustrative embodiments of the subject matter claimed below will now be disclosed. In the interest of clarify, some features of some actual implementations may not be described in this specification. It will be appreciated that in the development of any such actual embodiments, numerous implementation-specific decisions must be made to achieve the developer’s specific goals, such as compliance with system-related and business-related constraints, which will varyfrom one implementation to another. Moreover, it will be appreciated that such a development effort, even if complex and time-consuming, would be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.

[0013] The words and phrases used herein should be understood and interpreted to have a meaning consistent with the understanding of those words and phrases by those skilled in the relevant art. No special definition of a term or phrase, i.e., a definition that is different from the ordinary and customary' meaning as understood by those skilled in the art, is intended to be implied by consistent usage of the term or phrase herein. To the extent that a term or phrase is intended to have a special meaning, i.e., a meaning other than the broadest meaning understood by skilled artisans, such a special or clarifying definition will be expressly set forth in the specification in a definitional manner that provides the special or clarifying definition for the term or phrase, ft must also be noted that, as used in the specification and the appended claims, the singular forms “a,” “an,” and “the” include plural references unless otherwise specified.

[0014] For example, the following discussion contains a non-exhaustive list of definitions of several specific terms used in this disclosure (other terms may be defined or clarified in a definitional manner elsewhere herein). These definitions are intended to clarify the meanings of the terms used herein, ft is believed that the terms are used in a manner consistent with their ordinary meaning, but the definitions are nonetheless specified here for clarity.Definitions

[0015] As used herein, “antioxidant agents” means compounds that inhibit oxidation, a chemical reaction that can produce free radicals and chain reactions. Antioxidants are differentiated based on their reaction mechanisms and include: (1) primary antioxidants, and (2) secondary antioxidants.

[0016] As used herein, “barrier layer” means a layer used in a multilayer film to impart gas impermeability in addition to other desired properties to a multilayer structure. Barrier layers herein comprise high polarity polymers.

[0017] As used herein, “compatibility ” means the capability of the individual component substances in an immiscible polymer blend to exhibit interfacial adhesion, in which interfaces between phases or components are maintained by intermol ecul ar forces, chain entanglements, or both, across the interfaces — i.e., holding together of two bodies by interfacial forces or mechanical interlocking on a scale of micrometers or less. Further discussion of miscibility can be found in D. W. Fox and R. B. Allen, ‘Compatibility’. Encyclopedia of Polymer Science and Engineering, 2nd Ed., J. I. Kroschwitz, ed., Wiley Interscience, New York, 1985, Vol. 3, p. 784. Work, W. J., Hone, K., Hess, M., & UK, R S. (2004), Definitions of Terms Related to Polymer Blends,Composites and Multiphase Polymeric Materials, Pure and Applied Chemistry? 6 / 11, the substance of which is fully incorporated herein by reference.

[0018] As used herein, “compounding conditions” means temperature, pressure, and shear force conditions implemented in an extruder to provide intimate mixing of two or more polymers and optionally additives to produce a substantially homogeneous polymer product. The compounding conditions will be such that the specific energy from the compounder from shear and / or added heat are sufficient to melt the polymer components and homogenize them.

[0019] As used herein, “HDPE” means ethylene homopolymers and ethylene copolymers produced in a suspension, solution, slurry, or gas phase polymerization process and having a density in the range of 0.940 g / cm3to 0.970 g / cm3.

[0020] As used herein, “high polarity polymer” means a polar polymer comprising a sufficiently high amount of polar monomer and / or comonomer to result in the polar polymer having a low oxygen vapor transmission rate (OVTR), as measured by ASTM D3985, such as less than or equal to 200 cc,pm / m2*day»atm.

[0021] As used herein, “LDPE” means ethylene homopolymers and / or ethylene copolymers produced in a high pressure free radical polymerization and having a density in the range of 0.900 g / cm3to 0.940 g / cm3.

[0022] As used herein, “LLDPE” means ethylene copolymers produced in a suspension, solution, slurry, or gas phase polymerization process and having a density in the range of 0.900 g / cm’ to 0.940 g / cm’.

[0023] As used herein, “low polarity polymer” means a polymer having a sufficiently low amount of polar monomer or comonomer to result in the low polarity polymer having a high oxygen vapor transmission rate (OVTR), as measured by ASTM D3985, such as greater than or equal to 800 cc»pm / m2»day»atm. In some embodiments, the low polarity polymer comprises a polyolefin having no polarity, a copolymer of an olefin (such as ethylene or propylene) and an alpha mono-olefin comprising polar group, or a combination thereof. Low polarity polymers have a high degree of miscibility and / or compatibility with other low polarity polymers and are further characterized as providing one or more of high moisture barrier, high tensile strength, high tear strength, and high puncture resistance as measure by dart drop.

[0024] As used herein, “MDPE” means ethylene copolymers produced in a suspension, solution, slurry, or gas phase polymerization process and having a density in the range of 0.925 g / cm3to 0.940 g / cm3.

[0025] As used herein, “miscibility ” means the degree to which two polymers will mix to form a homogeneous polymer blends. Miscibility' is the capability' of a mixture to form a single phase over certain ranges of temperature, pressure, and composition. Whether or not a single phase existsdepends on the chemical structure, molar mass distribution, and molecular architecture of the components present. A single phase in a mixture may be confirmed by light scattering, x-ray scattering, and / or neutron scattering. For a two-component mixture, a necessary7and sufficient condition for stable or metastable equilibrium of a homogeneous, single-phase is:wherein AmixG is the Gibbs energy of mixing per unit volume, and <D the composition, where <D is usually taken as the volume fraction of one of the component substances. The system is unstable if the above second derivative is negative. The borderline (spinodal) between (meta)stable and unstable states is defined by the above second derivative equaling zero. Further discussion of miscibility can be found in J.M.G. Cowie, ‘Miscibility’, Encyclopedia of Polymer Science and Engineering, 2nd Ed., J.I. Kroschwitz. ed., Wiley Interscience, New York. 1985, Supplement, p. 455-480, and Work, W. J , Horie. K., Hess, M.. & UK, R. S. (2004). Definitions of Terms Related to Polymer Blends, Composites and Multiphase Polymeric Materials, Pure and Applied Chemislry76, 11, the substance of which is fully incorporated herein by reference.

[0026] As used herein, ‘“multilayer film” means a coextruded structure comprising at least a barrier layer, a structural layer, and a tie layer.

[0027] As used herein, “nonpolar comonomer” means a monomer unit containing only carbon and hydrogen.

[0028] As used herein, “nonpolar polymer” means a polymer or copolymer consisting of units derived from a nonpolar monomers.

[0029] As used herein, “olefin” as used herein, and alternatively referred to as “alkene,” is a linear, branched, or cyclic compound of carbon and hydrogen having at least one double bond.

[0030] As used herein, “polar monomer” means monomers containing highly electronegative atoms, such as chlorine, fluorine, oxygen, nitrogen, or sulfur, that give rise to polymers that contain permanent electric dipoles.

[0031] As used herein, “polar polymer” means a polymer or copolymer comprising units derived from a polar monomer. The term “polar polymer,” as used herein, refers to polymer formed from at least one monomer that comprises at least one heteroatom. Some examples of heteroatoms include O, N, P and S.

[0032] As used herein, “polymer recyclate” means post-consumer recycled (“PCR”) polymer and / or post-industrial recycled (“PIR”) polymer. Polymer recyclate is derived from an end product that has completed its life cycle as a consumer item and would otherwise be disposed of as waste (e.g., a polyethylene water bottle) or from plastic scrap that is generated as waste from an industrialprocess. Polymer recy elates herein are a mixture of a first low polarity polymer component and a high polarity polymer component comprising at least one polar monomer, such as produced by melting and mixing a barrier film having at least one layer of a first low polarity polymer component and at least on layer of a high polarity polymer component comprising at least one polar monomer.

[0033] As used herein, '‘polyolefin” as used herein, in some embodiments is a type of polymer with the general formula (CTECHRjn where R is an alkyl group, including, but not limited to LDPE, LLDPE, MDPE, EIDPE, and PP. Polyolefins are nonpolar polymers.

[0034] As used herein, “Functionalized polymer-based adhesive composition” means any composition comprising a functionalized polymer, alone or in combination with other polymers, where, in the context of coextruded layers of polymers, a layer of the functionalized polymer- based adhesive composition (or “tie layer”) will adhere better to both a first polymer layer and a second polymer layer than the first polymer layer and the second polymer layer would adhere to each other. Tie layers can also improve adhesion as described above where one or both polymer layers are replaced by a nonpolymeric layer.

[0035] As used herein, “primary' antioxidants” means compounds which function essentially as free radical terminators or scavengers. Primary' antioxidants react rapidly with peroxy and alkoxy radicals. The majority of primary antioxidants for polymers are sterically hindered phenols.

[0036] As used herein, “processability” as used herein, refers to how well a polymer composition can be formed into a cast of blown film of commercial quality or molded by injection or compression molding into a molded article of commercial quality at commercially acceptable rates using the equipment and conditions.

[0037] As used herein, "secondary antioxidants” means compounds which are preventive antioxidants that function by retarding chain initiation. Secondary' antioxidants react with hydroperoxides to yield non-radical products and are, therefore, frequently called hydroperoxide decomposers.

[0038] As used herein, “structural layer” means a layer used in a multilayer film to impart desired mechanical properties and / or resistance to moisture to the multilayer structure.

[0039] As used herein, “virgin” with respect to HDPE and / or other polymers, means preconsumer polymers. Pre-consumer polymers are obtained directly or indirectly from petrochemical feedstocks fed to a polymerization apparatus. Pre-consumer polyolefins can be subjected to post polymerization processes such as, but not limited to, extrusion, pelletization, visbreaking, and / or other processing completed before the product reaches the end-use consumer. In some embodiments, virgin HDPE may have a single heat history . In some embodiments, avirgin HDPE has more than one heat history. In some embodiments, a virgin HDPE comprises no additives. In some embodiments, a virgin HDPE comprises additives.

[0040] In the present description, the terms “monomer” and “comonomer” are used interchangeably. The terms mean any compound with a polymerizable moiety that is added to a reactor in order to produce a polymer. In those instances in which a polymer is described as comprising one or more monomers, e.g., a polymer comprising propylene and ethylene, the polymer, of course, comprises units derived from the monomers, e.g., — CH — CH2 — , and not the monomer itself, e.g., CH2=CH2. For example, when a copolymer is described as having an “ethylene” content of 35 wt.% to 55 wt.%, it is understood that the mer unit in the copolymer is derived from ethylene in the polymerization reaction and the derived units are present at 35 wt.% to 55 wt.%, based upon the weight of the copolymer.

[0041] In the present description, “multilayer film” is of particular concern and discussed throughout this description. When referring to a multilayer structure, the description can use a slash “ / ” to indicate that components to the left and right of the slash are in different layers and the relative position of components in layers can be so indicated by use of the slash to indicate layer boundaries.

[0042] The following abbreviations are used herein:' ABBREVIATION TERMEAA Copolymer of ethylene with acrylic acidEAO Copolymers of ethylene with at least one alpha-olefinEMAA Copolymer of ethylene with methacrylic acidEVA Copolymer of ethylene with vinyl acetateEVOH Saponified or hy drolyzed copolymer of ethylene and vinyl acetateHDPE High density polyethyleneIonomer Copolymers of ethylene and unsaturated carboxylic acid comonomers, such as but not limited to, EAA and EMAALDPE Low density polyethyleneLLDPE Linear low density polyethyleneMDPE Medium density polyethylenePA Polyamides, such as nylonPC PolycarbonatePCTFE PolychlorotrifluoroethylenePE Polyethylene (an ethylene homopoly mer or copolymer of a major portion of ethylene with one or more alpha-olefins and / or one or more polar comonomers)PET Polyethylene terephthalatePETG Glycol-modified polyethylene terephthalatePP Polypropylene homopotymer or copolymerPS PolystyrenePVDC Poly vinylidene chloride (also includes copolymers of vinylidene chloride, such as with vinyl chloride or methyl acrylate (MA)). wt% weight percent

[0043] It is noted that in this disclosure and particularly in the claims and / or paragraphs, terms such as “comprises”, “comprised”, “comprising” and the like can have the meaning attributed to it in U.S. patent law; e.g., they can mean “includes”, “included”, “including”, and the like; and thatterms such as “consisting essentially of’ and “consists essentially of’ have the meaning ascribed to them in U.S. patent law, e g., they allow for elements not explicitly recited, but exclude elements that are found in the prior art or that affect a basic or novel characteristic of the disclosure.Polymer Recv elate Feed Composition

[0044] A polymer recyclate feed composition comprises one or more polymer recyclates. Such polymer recyclates can comprise one or more polyolefins, one or more low polarity polymers, including polyolefins. Polyolefins, such as polyethylene and polypropylene, have superior moisture resistance properties and also provide essential mechanical properties such as, but not limited to, one or more of structural integrity’, puncture resistance, heat resistance, heat sealability, and / or abrasion resistance. Nonpolar polyolefins include, but are not limited to, HDPE, LDPE, LLDPE, MDPE, and PP.

[0045] Low polarity7polymers also provide one or more of structural integrity7, moisture barrier, puncture resistance, heat resistance, heat sealability, and / or abrasion resistance. Such low polarity polymers include copolymers of units derived from ethylene and units derived from one or more of alpha mono-olefins comprising polar groups. Such low polarity polymers include, but are not limited to, EVA, ionomers (such as, but not limited to, EAA and EMAA), PET, PC, and / or PS, which provide one or more of moisture resistance, structural integrity', puncture resistance, heat resistance, heat sealability, and / or abrasion resistance.

[0046] In some embodiments, the polymer recyclate feed composition comprises one or more polymer recyclates. In some embodiments, the one or more polymer recyclates comprises one or more low polarity polymer recyclates. In some embodiments, the one or more low polarity' polymer recyclates are compatible.

[0047] In some embodiments, the polymer recyclate feed composition further comprises one or more virgin polymers. In some embodiments, the one or more virgin polymers comprises one or more low polarity virgin polymers. In some embodiments, the one or more low polarity7virgin polymers are compatible with the one or more low polarity polymer recyclates.

[0048] In some embodiments, one or more low polarity polymer recyclates and / or one or more low polarity virgin polymers comprise one or more polyolefins. In some embodiments, one or more low polarity polymer recyclates and / or one or more low polarity virgin polymers is a blend of two or more polyolefins such as, but not limited to, a blend of low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene, high density polyethylene (HDPE), and / or polypropylene (PP).

[0049] Suitable polyethylenes for one or more low polarity polymer recyclates and / or one or more low polarity7virgin polymers include ethylene homopolymers and copolymers of units derived from ethylene and units derived from one or more of C3-C20 alpha-olefins or mixturesthereof. In some embodiments, the units derived from the one or more Cs-Cs alpha-olefin comonomers are present in amounts up to 15 wt. %, based upon the total weight of the copolymer of ethylene. The ethylene homopolymers and copolymers can be produced using either Ziegler Natta catalyst, chromium-based catalyst, or single-site catalyst, e.g., metallocene catalyst. The ethylene homopolymers and copolymers can be produced using a gas phase process, high pressure process, slurry process, or solution process. Ethylene homopolymers and ethylene-Cs-Cs alphaolefin copolymers include very low density polyethylene (VLDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE) and high density polyethylene (HDPE). VLDPE is defined as having a density of 0.860 to 0.910 g / cm3, as measured by ASTM D-1505 "Column Method / ’ LDPE and LLDPE are defined as having densities in the range of from 0.900 to 0.930 g / cm3. MDPE is defined as having a density of 0.925 to 0.945 g / cm3. HDPE is defined as having a density of at least 0.941 g / cm3, preferably from 0.945 to 0.969 g / cm3. The ethylene homopolymers and copolymers preferably have melt indexes (Mis), as measured by ASTM D 1238, condition 190° C. / 2.16 kg, from 0.01 to 600 dg / min., preferably, from 0. 1 to 200 dg / min., more preferably from 1 to 100 dg / min.

[0050] In some embodiments, LDPE is derived from ethylene homopolymers, copolymers of units derived from ethylene and units derived from one or more of C3-C12 alpha-olefins, copolymers of units derived from ethylene and units derived from one or more of alpha monoolefins comprising polar groups, or mixtures thereof.

[0051] In some embodiments, LDPE homopolymers can be produced in a high pressure, free- radical polymerization process, such as in one or more tubular reactors, one or more autoclave reactors, or a combination thereof. Operating conditions for the high-pressure process can include, but are not limited to, a pressure in the range of from 70 MPa to 700 MPa and a temperature in the range of from 150°C to 500°C. Such homopolymers have a high degree of long-chain branching and a density in the range of from 0.900 g / cm3to 0.940 g / cm3.

[0052] In some embodiments, LDPE copolymers of ethylene and C3-C12 alpha-olefins can be produced in a high pressure, free-radical polymerization process, such as in one or more tubular reactors, one or more autoclave reactors, or a combination thereof. Such C3-C12 alpha-olefins include, but are not limited to, substituted or unsubstituted Ci to C12 alpha olefins such as propylene, butene, pentene, hexene, heptene, octene, nonene, decene, undecene, dodecane, and isomers thereof. When present, comonomers can be present in amounts up to 15 wt%, 10 wt%. or 5 wt%. Operating conditions for the high-pressure process can include, but are not limited to, a pressure in the range of from 70 MPa to 700 MPa and a temperature in the range of from 150°C to 500°C. Such homopolymers have a high degree of long-chain branching and a density in the range of from 0.900 g / cm3to 0.940 g / cm3.

[0053] In some embodiments, LDPE copolymers of ethylene and one or more of alpha mono- olefins comprising polar groups can be produced in a high pressure, free-radical polymerization process, such as in one or more tubular reactors, one or more autoclave reactors, or a combination thereof. Such alpha mono-olefins comprising polar groups include, but are not limited to, methacrylic acids, esters (e.g., acetate esters, such as vinyl acetate), nitriles, and amides, such as acrylic acid, methacrylic acid, cyclohexyl methacrylate, methyl acrylate, acrylonitrile, acrylamide, or mixtures thereof. When present, comonomers can be present in amounts up to 15 wt%, 10 wt%, or 5 wt%. Operating conditions for the high-pressure process can include, but are not limited to, a pressure in the range of from 70 MPa to 700 MPa and a temperature in the range of from 150°C to 500°C. Such homopolymers have a high degree of long-chain branching and a density in the range of from 0.900 g / cm3to 0.940 g / cm3.

[0054] LDPE as described above, can be characterized by having: i) a density in the range of from 0.900 g / cm3to 0.940 g / cm3or from 0.915 g / cm3to 0.935 g / cm3; ii) a melt index (2.16 kg, 190°C) less than or equal to 5.0 g / 10 min., less than or equal to 1.0 g / 10 min., less than or equal to 0.5 g / 10 min., less than or equal to 0.2 g / 10 min., or less than or equal to 0.1 g / 10 min.; iii) a molecular weight distribution (Mw / Mn) greater than 4.0, greater than 8.0, or greater than 15, and / or less than 35, less than 30, or less than 25; iv) a weight average molecular weight (Mw) greater than or equal to 100,000 daltons, greater than or equal to 150,000 daltons, greater than or equal to 200,000 daltons, or greater than or equal to 250,000 daltons, and / or less than or equal to 600,000 daltons, less than or equal to 500,000 daltons, less than or equal to 400,000 daltons, or less than or equal to 300,000 daltons; and v) a melt elasticity (“ER”) greater than or equal to 1.0, greater than or equal to 1.4, or greater than or equal to 2.0.

[0055] Suitable polypropylenes for one or more low polarity polymer recy elates and / or one or more low polarity virgin polymers include propylene homopolymers and copolymers, including plastomers, having of units derived from propylene and units derived one or more of ethylene and C4-C20 alpha-olefins or mixtures thereof. Preferably, the units derived from one or more of ethylene and C4-C10 alpha-olefin comonomers are present in amounts up to 35 wt. %, based upon the total weight of the copolymer of propylene. The propylene homopolymers and copolymers can be produced using either Ziegler Natta or single-site catalysts, e.g., metallocene catalysts. The propylene homopolymers and copolymers can be produced using a gas phase process, slurry' process, or solution process. In some embodiments, when the propylene polymer is a copolymer, it preferably contains 2 to 6 wt. %, based upon the total weight of the copolymer, of ethylene derived units as a comonomer.

[0056] In some embodiments, a first low polarity polymer component comprises a copolymer of ethylene and one or more polar comonomer, a copolymer of propylene and one or more polarcomonomers, or a combination thereof, wherein the low first polarity polymer component has an oxygen vapor transmission rate (OVTR), as measured by ASTM D3895, of greater than or equal to 800 cc*pm / m2«dayatm. greater than or equal to 900 cc*pm / m2*dayatm, or greater than or equal to 1,000 cc«pm / m2«da atm.

[0057] One or more low polarity polymer recyclates and / or one or more low polarity virgin polymers can also be formed from a blend of two or more polyethylenes, two or more polypropylenes, or one or more polyethylenes and one or more polypropylenes. In some embodiments, one or more low polarity polymer recyclates and / or one or more low polarity virgin polymers can also be formed from a blend of two or more polyolefins, two or more low polarity polymers (other than polyolefins), or one or more polyolefins and one or more low polarity polymers (other than polyolefins).Crosslinking Process

[0058] The method disclosed herein encompasses any crosslinking process capable of increasing the molecular average molecular weight of the polymer recyclate feed compositions disclosed herein. In some embodiments, the crosslinking process comprises a chemical crosslinking process, a moisture crosslinking process, a radiation crosslinking process, or a photocrosslinking process.

[0059] Crosslinking processes disclosed herein are applied to a polymer recyclate feed composition a first weight average molecular weight (Mwi) to produce a modified polymer recyclate product having a second weight average molecular weight (MW2), wherein MW2 is greater than Mwi. In some embodiments, Mw2 / Mwiis greater than or equal to 1. 1, greater than or equal to 1.5, greater than or equal to 2.0, greater than or equal to 5.0, or greater than or equal to 10.0.Chemical Crosslinking Process

[0060] In some embodiments, a chemical crosslinking process comprises mixing the polymer recyclate feed composition and a free radical initiator under heat sufficient to decompose the free radical initiator to form free radicals. The free radicals react with the polymer recyclate feed composition to form polymer recyclate radicals. The polymer recyclate free radicals react by free radical addition to form the modified polymer recyclate product. In some embodiments, molecular weight of the polymer product is increase by polymer recyclate radicals are joined end-to-end forming longer chains, end-to-backbone forming branched connections, backbone-to-backbone forming connection of polymer chains at any point along their lengths, or a combination thereof.

[0061] In some embodiments, the free radical initiator comprises an organic peroxide, an organic azide, or a combination thereof.

[0062] The chemical crosslinking process produces a first modified polymer recyclate product.The first modified polymer recyclate product has crosslinking characteristic to the chemicalcrosslinking process. The chemical crosslinking reaction includes a mixture of chain scission and chain addition (end-to-end, end-to-backbone, backbone-to-backbone, or a combination thereof). The ratio of chain scission to chain addition during the crosslinking reaction will control the final molecular structure and molecular weight of the crosslinked product and in turn the mechanical properties of the crosslinked product. The ratio of chain scission to chain addition during the crosslinking reaction can be controlled by the reaction temperature, the amount of free radical initiator, the type of polymer, the intensity of mixing conditions, or a combination thereof.- Moisture Crosslinking Process

[0063] In some embodiments, a moisture-cure crosslinking process comprises mixing the polymer recy elate feed composition, a free radical initiator, and a moisture-cure crosslinking agent under heat sufficient to decompose the chemical crosslinking agent to form free radicals. The free radicals react with the polymer recyclate feed composition and the moisture-cure crosslinking agent to form polymer recyclate graft polymer having pendant groups comprising the moisturecure crosslinking agent. The polymer recyclate graft polymer is hydrolyzed to form a polymer recyclate having pendant hydroxyl groups. Crosslinks are them formed by condensation of pendant hydroxyl groups.

[0064] In some embodiments, the moisture-cure crosslinking agent comprises a silane, a urethane, or a combination thereof.

[0065] The moisture-cure crosslinking process produces a second modified polymer recyclate product. The second modified polymer recyclate product has crosslinking characteristic to the chemical crosslinking process. The chemical crosslinking reaction includes a mixture of chain addition (end-to-end, end-to-backbone, backbone-to-backbone, or a combination thereof). The amount of crosslinking during the crosslinking reaction will control the final molecular structure and molecular weight of the crosslinked product and in turn the mechanical properties of the crosslinked product. The amount of crosslinking can be controlled by the reaction temperature, the amount of free radical initiator, the amount of crosslinking agent, the type of polymer, the intensity of mixing conditions, or a combination thereof.- Radiation Crosslinking Process

[0066] In some embodiments, a radiation crosslinking process comprises subjecting the polymer recyclate feed composition to ionizing radiation to form polymer recyclate free radicals. The polymer recyclate free radicals react by free radical addition to form the modified polymer recyclate product.

[0067] In some embodiments, the ionizing radiation comprises gamma radiation, electron beam radiation, or a combination thereof.

[0068] The radiation crosslinking process produces a third modified polymer recyclate product. The third modified polymer recyclate product has crosslinking characteristic to the radiation crosslinking process. The radiation crosslinking reaction includes a mixture of chain scission and chain addition (end-to-end, end-to-backbone, backbone-to-backbone, or a combination thereof). The ratio of chain scission to chain addition during the crosslinking reaction will control the final molecular structure and molecular weight of the crosslinked product and in turn the mechanical properties of the crosslinked product. The ratio of chain scission to chain addition during the crosslinking reaction can be controlled by type of radiation, the intensity of radiation, the type of polymer, the intensity of mixing conditions, or a combination thereof.- Photo-Crosslinking Process

[0069] In some embodiments, a photo-crosslinking process comprises mixing the polymer recyclate feed composition and a photo-initiator to form a mixture. The mixture is exposed to light to activate the photo-initiator resulting in formation of polymer recyclate radicals. The modified polymer recyclate product is formed by free radical addition of polymer recyclate radicals.

[0070] In some embodiments, the photo-initiator comprises an benzoin ether, a camphorquinone, or a combination thereof.

[0071] The photo-crosslinking process produces a fourth modified polymer recyclate product. The fourth modified polymer recyclate product has crosslinking characteristic to the chemical crosslinking process. The photo-crosslinking reaction includes a mixture of chain scission and chain addition (end-to-end, end-to-backbone, backbone-to-backbone, or a combination thereof). The ratio of chain scission to chain addition during the crosslinking reaction will control the final molecular structure and molecular weight of the crosslinked product and in turn the mechanical properties of the crosslinked product. The ratio of chain scission to chain addition during the crosslinking reaction can be controlled by the type of photo-initiator, the amount of photo-initiator, the type of polymer, the intensity of mixing conditions, or a combination thereof.Antioxidants

[0072] In some embodiments, primary and / or secondary antioxidants are added to stabilize the reactions for any exposure to oxygen during compounding.

[0073] Primary antioxidants react rapidly with peroxy and alkoxy radicals. Examples of primary antioxidants, sometimes termed long-term antioxidants.” include phenolic antioxidants and hindered amine antioxidants, such as are disclosed in U.S. Pat. No. 6,392,056, the disclosure of which is incorporated herein in its entirety. Suitable primary antioxidants include, but are not limited to, Irganox™ antioxidants available from BASF, such as Irganox™ 1010, Irganox™ 1076, Irganox™ 1098, Irganox™ 1330, Irganox™ 1425 WL, Irganox™ 3114, Irganox™ 245 andIrganox™ 1135. Examples of suitable antioxidants, including phenolic antioxidants and hindered amine antioxidants, are described in U.S. Pat. No. 7,285,617, the disclosure of which is incorporated herein in its entirety.

[0074] Nonlimiting examples of primary antioxidants include 2.6-di-tert.butyl-4-methyl phenol. pentaerythrityl-tetrakis(3-(3',5'-di-tert.butyl-4-hydroxyphenyl)- propionate, octadecyl 3- (3',5'-di-tert.butyl-4-hydroxyphenyl)propi onate, l,3,5-tri-methyl-2,4,6-tris-(3,5-di-tert.butyl-4- hydroxyphenyl)benzene, l,3,5-tris(3',5'-di-tert.butyl-4'-hydroxybenzyl)-isocyanurate, bis-(3,3- bis-(4-'-hydroxy-3'-tert.butylphenyl)butanic acid)-glycolester, N,N'-hexamethylene bis(3,5-di- tert.butyl-4-hydroxy-hydrocinnamamide, 2,5,7,8-Tetramethyl-2(4',8',12'- trimethyltridecyl)chroman-6-ol, 2,2'-ethylidenebis(4,6-di -tert. butylphenol), l, l,3-tris(2-methyl-4- hydroxy-5-tert.buty Iphenyl) butane, 1 ,3,5-tris(4-tert.butyl-3-hydroxy-2,6-dimethylbenzyl)-l ,3,5- triazine-2,4,- 6-(lH,3H,5H)-trione, 3,9-bis(l,l-dimethyl-2-(P-(3-tert.butyl-4-hydroxy-5- methylphenyl) propionyloxy)ethyl)-2,4,8,10-tetraoxaspiro(5,5) undecane, l,6-hexanediyl-bis(3,5- bis(l.l-dimethylethyl)-4-hydroxybenzene-propanoate- ). 2,6-di-tert.butyl-4-nonylphenol, 4.4'- butylidenebis(6-tert.butyl-3-methylphenol), 2,2'-methylene bis(4-methyl-6-tert.butylphenol), and triethyleneglycol-bis-(3-tert.butyl-4-hydroxy-5 methylphenyl) propionate.

[0075] Secondary antioxidants, sometimes termed “short-term antioxidants,’' can be added to the mixer / extruder at any convenient location. Secondary antioxidants are available commercially, such as the Irgafos™ antioxidants available from BASF, such as Irgafos™ 168, Irgafos™ 126, Irganox™ PS 800 and Irganox™ PS 802.

[0076] Examples of secondary antioxidants include, for example, aliphatic thiols and phosphites and phosphonites. Specific examples of secondary antioxidants include distearyl pentaerythritol diphosphite, isodecyl diphenyl phosphite, diisodecyl phenyl phosphite, tris(2,4-di- t-buty lphenyl)phosphite, dilauryl-|3,|3-thiodipropionate, -naphthyl disulfide, thiol- -naphthol, 2- mercaptobenzothiazole, benzothiazyl disulfide, phenothiazine, tris(p-nonylphenyl)phosphite, and zinc dimethyldithiocarbamate.Products

[0077] In some embodiments, a modified recyclate product comprises the first modified polymer recyclate product, the second modified polymer recyclate product, the third modified polymer recyclate product, the fourth modified polymer recyclate product, or a combination thereof.

[0078] In some embodiments, the increased molecular weight of the modified recyclate product results in improved mechanical properties, including but not limited to. one or more of tensile strength, impact strength, toughness, elongation at break, abrasion resistance, viscosity in melt state, stress crack resistance, tear strength, and creep resistance.

[0079] In some embodiments, an article is formed from the modified recyclate product, either alone or in combination with other polymers. Ideally, articles comprising at least a portion of the modified recyclate product have competitive, equivalent, or superior performance as compared to the same articles formed from all virgin polymers.

[0080] In some embodiments, an article herein comprises a cast or blown film or one or more layers of a cast or blown multilayer film.

[0081] In some embodiments, an article herein comprises a container, such as but not limited to, blow' molded, rotational molded, compression molded, and injection molded bottles or other containers.Certain Embodiments

[0082] Disclosed is method for improving mechanical properties polymer recyclates through an increase in molecular weight. In a first set of embodiments, a method for producing a modified polymer recyclate product, the method comprises subj ecting a polymer recyclate feed composition to a crosslinking process to produce a modified polymer recyclate product, wherein the polymer recyclate feed composition has a first weight average molecular weight (Mwi). the modified polymer recyclate product has a second weight average molecular weight (Mw2), and weight MW2 is greater than Mwi. In some embodiments, Mw / Mwi is greater than or equal to 1.1, greater than or equal to 1.5, greater than or equal to 2.0, greater than or equal to 5.0, or greater than or equal to 10.0.

[0083] In further embodiments of the first set of embodiments, in addition to the above limitations, the polymer recyclate feed composition comprises one or more polymer recyclates.

[0084] In further embodiments of the first set of embodiments, in addition to one or more of the above limitations, the one or more polymer recyclates comprises one or more low polarity polymer recyclates.

[0085] In further embodiments of the first set of embodiments, in addition to one or more of the above limitations, the one or more low' polarity polymer recyclates are compatible.

[0086] In further embodiments of the first set of embodiments, in addition to one or more of the above limitations, the polymer recyclate feed composition further comprises one or more virgin polymers.

[0087] In further embodiments of the first set of embodiments, in addition to one or more of the above limitations, the one or more virgin polymers comprises one or more low' polarity' virgin polymers.

[0088] In further embodiments of the first set of embodiments, in addition to one or more of the above limitations, the one or more low polarity virgin polymers are compatible with the one or more low polarity polymer recyclates.

[0089] In a second set of embodiments of the method, in addition to the limitations of any of the first set of embodiments, the crosslinking process comprises a chemical crosslinking process.

[0090] In further embodiments of the second set of embodiments, in addition to one or more of the above limitations, the chemical crosslinking process comprises: mixing the polymer recy elate feed composition and a free radical initiator under heat sufficient to decompose the free radical initiator to form free radicals; reacting the free radicals with the polymer recy elate feed composition to form polymer recy elate radicals; and forming the modified polymer recyclate product by free radical addition of polymer recyclate radicals.

[0091] In further embodiments of the second set of embodiments, in addition to one or more of the above limitations, the free radical initiator comprises an organic peroxide, an organic azide, or a combination thereof.

[0092] In a third set of embodiments of the method, in addition to the limitations of any of the first set of embodiments, the crosslinking process comprises a moisture-cure crosslinking process.

[0093] In further embodiments of the third set of embodiments, in addition to one or more of the above limitations, the moisture-cure crosslinking process comprises: mixing the polymer recyclate feed composition, a free radical initiator, and a moisture-cure crosslinking agent under heat sufficient to decompose the chemical crosslinking agent to form free radicals; reacting the free radicals with the polymer recyclate feed composition and the moisturecure crosslinking agent to form polymer recyclate graft polymer having pendant groups comprising the moisture-cure crosslinking agent; hydrolyzing the moisture-cure crosslinking agent to form a polymer recyclate having pendant hydroxyl groups; and forming crosslinks by condensation of pendant hydroxyl groups.

[0094] In further embodiments of the third set of embodiments, in addition to one or more of the above limitations, the moisture-cure crosslinking agent comprises a silane, a urethane, or a combination thereof.

[0095] In a fourth set of embodiments of the method, in addition to the limitations of any of the first set of embodiments, the crosslinking process comprises a radiation crosslinking process.

[0096] In further embodiments of the fourth set of embodiments, in addition to one or more of the above limitations, the radiation crosslinking process comprises: subjecting the polymer recyclate feed composition to ionizing radiation to form polymer recyclate free radicals; andforming the modified polymer recyclate product by free radical addition of polymer recyclate radicals.

[0097] In further embodiments of the fourth set of embodiments, in addition to one or more of the above limitations, the ionizing radiation comprises gamma radiation, electron beam radiation, or a combination thereof.

[0098] In a fifth set of embodiments of the method, in addition to the limitations of any of the first set of embodiments, the crosslinking process comprises a photo-crosslinking process.

[0099] In further embodiments of the fifth set of embodiments, in addition to one or more of the above limitations, the photo-crosslinking process comprises: mixing the polymer recyclate feed composition and a photo-initiator to form a mixture; exposing the mixture to light to activate the photo-initiator resulting in formation of polymer recyclate radicals; and forming the modified polymer recyclate product by free radical addition of polymer recyclate radicals.

[0100] In further embodiments of the fifth set of embodiments, in addition to one or more of the above limitations, the photo-initiator comprises an benzoin ether, a camphorquinone, or a combination thereof.

[0101] In another aspect, a modified recyclate product comprises a product of the method of the first set of embodiments, a product of the method of the second set of embodiments, a product of the method of the third set of embodiments, a product of the method of the fourht set of embodiments, a product of the method of the fifth set of embodiments, or a combination thereof.

[0102] In another aspect, an article comprises the modified recyclate product, wherein in further embodiments, the article comprises a film or a container.EXAMPLES

[0103] The following examples are included to demonstrate preferred embodiments of the invention. It should be appreciated by those of skill in the art that the techniques disclosed in the examples which follow represent techniques discovered by the inventor to function well in the practice of the invention, and thus can be considered to constitute preferred modes for its practice. However, those of skill in the art should, in light of the present disclosure, appreciate that many changes can be made in the specific embodiments which are disclosed and still obtain a like or similar result without departing from the spirit and scope of the invention.Test Methods

[0104] Abrasion resistance measurements are performed in accord with ASTM D4020: ■‘Standard Specification for Ultra-High-Molecular-Weight Polyethylene Molding and ExtrusionMaterials7’ or ASTM D1044: "Standard Test Method for Resistance of Transparent Plastics to Surface Abrasion.”

[0105] Creep resistance measurements are performed in accord with ASTM D2990: “Standard Test Methods for Tensile, Compressive, and Flexural Creep and Creep-Rupture of Plastics.”

[0106] Dart drop (g): Measurements were made following ASTM DI 709-04 (2016), using a dart drop height of 26 in (F50).

[0107] Densities are determined in accordance with ASTM D-792 andASTM D-1505 / ISO-1183.

[0108] Elongation at break (%): Elongation at break was measured according toASTM D-638.

[0109] Elongation at break measurements are performed in accord with ASTM D638.

[0110] Film Elmendorf Tear (g / mil) was made according to ASTMD 1922.[OHl] Gloss (45°) is measured as specified by ASTM D2457.

[0112] Haze (%): Film haze measurements were made following ASTM D1003.

[0113] Impact strength measurements are performed in accord with ASTM D256: “Standard Test Methods for Determining the Izod Pendulum Impact Resistance of Plastics”; ASTM D4812: “Standard Test Method for Unnotched Cantilever Beam Impact Resistance of Plastics”; ASTM D746: “Standard Test Method for Brittleness Temperature of Plastics and Elastomers by Impact.”

[0114] Melt elasticity (“ER”) is determined as discussed in R. Shroff and H. Mavridis, “New Measures of Polydispersity from Rheological Data on Polymer Melts,” J. Applied Polymer Science 57 (1995) 1605. See also U.S. Pat. Nos. 7,238,754. 6,171,993 and 5,534,472 (col. 10, lines 20-30), the teachings of which are incorporated herein by reference. Thus, storage modulus (G') and loss modulus (G”) are measured. The nine lowest frequency points are used (five points per frequency decade) and a linear equation is fitted by least-squares regression to log G' versus log G”. ER is then calculated from:ER = (1.781 x 10‘3) x G' at a value of G”=5,000 dyn / cm2. The same procedure and equation for the ER calculation was used for both linear and long-chain-branched polyolefins.

[0115] Melt index (“I2”) was determined by ASTM D-1238-E (190°C / 2.16 kg).

[0116] Molecular weight distribution (“MWD”) as well as the molecular weight averages (number-average molecular weight, Mnweight-average molecular weight, Mw, and z-average molecular weight, Mz) are determined using a high temperature Polymer Char gel permeation chromatography (“GPC”), also referred to as size exclusion chromatography (“SEC”), equipped with a filter-based infrared detector, IR5, a four-capillary differential bridge viscometer, and a Wyatt 18-angle light scattering detector. Mn, Mw, Mz,MWD, and short chain branching (SCB)profiles are reported using the IR detector, whereas long chain branch parameter, g', is determined using the combination of viscometer and IR detector at 145°C. Three Agilent PLgel Olexis GPC columns are used at 145 °C for the polymer fractionation based on the hydrodynamic size in 1,2,4- trichlorobenzene (TCB) with 300 ppm antioxidant butylated hydroxytoluene (BHT) as the mobile phase. 16 mg polymer is weighted in a 10 mL vial and sealed for the GPC measurement. The dissolution process is obtained automatically (in 8 ml TCB) at 160°C for a period of 1 hour with continuous shaking in an Agilent autosampler. 20 pL Heptane was also injected in the vial during the dissolution process as the flow marker. After the dissolution process, 200 pL solution was injected in the GPC column. The GPC columns are calibrated based on twelve monodispersed polysty rene (PS) standards (provided by PSS) ranging from 578 g / mole to 3,510,000 g / mole. The comonomer compositions (or SCB profiles) are reported based on different calibration profiles obtained using a series of relatively narrow polyethylene (polyethylene with 1 -hexene and 1- octene comonomer were provided by Polymer Char, and polyethylene with 1 -butene were synthesized internally) with known values of CH3 / IOOO total carbon, determined by an established solution NMR technique. GPC one software w as used to analyze the data. The long chain branch parameter, g'. is determined by the equation: g' = [ll] / [T|]lin where, [r|] is the average intrinsic viscosity^ of the polymer that is derived by summation of the slices over the GPC profiles as follows:where Ci is the concentration of a particular slice obtained from IR detector, and [q]}is the intrinsic viscosity of the slice measured from the viscometer detector, |q I iin is obtained from the IR detector using Mark-Houwink equation ( [n] 1 in = Z KM31pha) for a linear high density polyethylene, where Mi is the viscosity-average molecular weight for a reference linear polyethylene, K and a are Mark-Houwdnk constants for a linear polymer, which are K=0.000374, a=0.7265 for a linear polyethylene and K=0.00041, a=0.6570 for a linear polypropylene.10117] Oxygen gas transmission rate (OVTR) can be measured by ASTM D3985.

[0118] Shear rheological measurements are performed in accord with ASTM 4440-95a, which characterize dynamic viscoelastic properties (storage modulus, G', loss modulus, G” and complex viscosity, r . as a function of oscillation frequency, tn). A rotational rheometer (TA Instruments) is used for the rheological measurements. A 25 mm parallel-plate fixture was utilized. Samples were compression molded in disks (~ 29 mm diameter and ~ 1.3 mm thickness) using a hot press at 190 °C. An oscillatory frequency sweep experiment (from 398.1 rad / s to 0.0251 rad / s) wasapplied at 190°C. The applied strain amplitude is ~ 10% and the operating gap is set at 1 mm. Nitrogen flow was applied in the sample chamber to minimize thermal oxidation during the measurement.

[0119] Stress crack resistance measurements are performed in accord with ASTM DI 693: “Standard Test Method for Environmental Stress-Cracking of Ethylene Plastics.”

[0120] Tensile strength measurements are performed in accord with ASTM D638: “Standard Test Method for Tensile Properties of Plastics.”

[0121] Tensile stress at break (MPa): Tensile stress at break was measured according to ASTM D-638. This test is dependent on film sample thickness. For the measurements provided here, a thickness of about 46 pm to 55 pm was used.

[0122] Toughness can be inferred from a combination of tensile and impact tests.

[0123] Viscosity7in Melt State measurements are performed in accord with ASTM D1238: “Standard Test Method for Melt Flow Rates of Thermoplastics by Extrusion Plastometer.”

[0124] Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the processes, machines, film structures, composition of layers, means, methods, and / or steps described in the specification. As one of the ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, film structures, composition of layers, means, methods, and / or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein, may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, film structures, composition of layers, means, methods, and / or steps.

Claims

CLAIMSWhat is claimed is:

1. A method for producing a modified polymer recy elate product, the method comprising subjecting a polymer recy elate feed composition to a crosslinking process to produce a modified polymer recyclate product, wherein the polymer recy elate feed composition has a first weight average molecular weight (Mwi). the modified polymer recyclate product has a second weight average molecular weight (MW2). and weight MW2 is greater than Mwi.

2. The method of claim 1. wherein weight MW2 / Mwiis greater than or equal to 1.1, greater than or equal to 1.5, greater than or equal to 2.0, greater than or equal to 5.0, or greater than or equal to 10.0.

3. The method of claim 1 or 2, wherein the polymer recyclate feed composition comprises one or more polymer recy elates.

4. The method of claim 3, wherein the one or more polymer recyclates comprises one or more low polarity polymer recyclates.

5. The method of claim 4, wherein the one or more low polarity polymer recyclates are compatible.

6. The method of any one of claims 3 through 5, wherein the polymer recyclate feed composition further comprises one or more virgin polymers.

7. The method of any one of claims 6, wherein the one or more virgin polymers comprises one or more low polarity virgin polymers.

8. The method of claim 7, wherein the one or more low polarity virgin polymers are compatible with the one or more low polarity polymer recyclates.

9. The method of any one of claims 1 through 8, wherein the crosslinking process comprises a chemical crosslinking process.

10. The method of claim 9. wherein the chemical crosslinking process comprises: mixing the polymer recyclate feed composition and a free radical initiator under heat sufficient to decompose the free radical initiator to form free radicals; reacting the free radicals with the polymer recyclate feed composition to form polymer recyclate radicals; and forming the modified polymer recyclate product by free radical addition of polymer recyclate radicals.

11. The method of claim 10, wherein the free radical initiator comprises an organic peroxide, an organic azide, or a combination thereof.

12. A first modified polymer recy elate product produced by any one of claims 9 through 11.

13. The method of any one of claims 1 through 8, wherein the crosslinking process comprises a moisture-cure crosslinking process.

14. The method of claim 13, wherein the moisture-cure crosslinking process comprises: mixing the polymer recy elate feed composition, a free radical initiator, and a moisture-cure crosslinking agent under heat sufficient to decompose the chemical crosslinking agent to form free radicals; reacting the free radicals with the polymer recy elate feed composition and the moisturecure crosslinking agent to form polymer recyclate graft polymer having pendant groups comprising the moisture-cure crosslinking agent; hydrolyzing the moisture-cure crosslinking agent to form a polymer recyclate having pendant hydroxyl groups: and forming crosslinks by condensation of pendant hydroxyl groups.

15. The method of claim 14, wherein the moisture-cure crosslinking agent comprises a silane, a urethane, or a combination thereof.

16. A second modified polymer recyclate product produced by any one of claims 13 through15.

17. The method of any one of claims 1 through 8, wherein the crosslinking process comprises a radiation crosslinking process.

18. The method of claim 17, wherein the radiation crosslinking process comprises: subjecting the polymer recyclate feed composition to ionizing radiation to form polymer recyclate free radicals; and forming the modified polymer recyclate product by free radical addition of polymer recyclate radicals.

19. The method of claim 18, wherein the ionizing radiation comprises gamma radiation, electron beam radiation, or a combination thereof.

20. A third modified polymer recyclate product produced by any one of claims 17 through 19.

21. The method of any one of claims 1 through 8, wherein the crosslinking process comprises a photo-crosslinking process.

22. The method of claim 21, wherein the photo-crosslinking process comprises: mixing the polymer recy elate feed composition and a photo-initiator to form a mixture; exposing the mixture to light to activate the photo-initiator resulting in formation of polymer recy elate radicals; and forming the modified polymer recyclate product by free radical addition of polymer recyclate radicals.

23. The method of claim 22, wherein the photo-initiator comprises an benzoin ether, a camphor quinone, or a combination thereof.

24. A fourth modified polymer recyclate product produced by any one of claims 21 through 23.

25. A modified recyclate product comprising the first modified polymer recyclate product of claim 12, the second modified polymer recyclate product of claim 16, the third modified polymer recyclate product of claim 20, the fourth modified polymer recyclate product of claim 24, or a combination thereof.

26. An article comprising the modified recyclate product of claim 25.

27. The article of claim 26, comprising a film or a container.

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