Reinforced toughened polyolefin material and method of making and use thereof

Abstract

The application discloses a kind of reinforced toughened polyolefin materials and its preparation method and application.The polyolefin material includes the following component raw materials by weight fraction: modified polypropylene A 75~95 parts, modified silicon dioxide B 1~20 parts, auxiliary agent 1~7 parts;Wherein, modified polypropylene A is modified by grafting monomer, and the structural formula (I) of grafting monomer is: formula (I) in it: X is linear alkyl containing 1~10 carbon atoms or saturated fatty alcohol group, or does not contain X;The surface of modified silicon dioxide B is modified with cyclodextrin derivative.The application utilizes the inclusion of cyclodextrin derivative to organic molecule, by the host-guest reaction between cylindrical molecule beta-cyclodextrin and benzene ring, make polypropylene molecular chain crosslinking, strengthen phase interface interaction force, so that polyolefin material has excellent rigid and tough balance.

Description

Technical Field

[0001] This invention relates to a reinforced and toughened polyolefin material, its preparation method, and its application. Background Technology

[0002] Polypropylene (PP) possesses excellent comprehensive mechanical properties, heat resistance, chemical resistance, insulation, molding and processing performance, and low density, coupled with its relatively low cost, making it widely applicable. PP is used in automotive parts, electrical components, chemical equipment, building materials, insulation materials, packaging materials, textiles, fishing nets, and daily necessities. The application areas of PP are expanding year by year, and its production growth rate has consistently ranked first among general-purpose plastics in recent years. However, PP has high notch sensitivity and low notched impact strength, especially at low temperatures, which significantly limits its further promotion and application. Therefore, strengthening and toughening PP has gradually become a key research focus both domestically and internationally.

[0003] When modifying polyolefins with inorganic nanomaterials, the inventors discovered that due to the small particle size, large specific surface area, strong surface adsorption force, and large surface energy of nanomaterials, the agglomeration problem can lead to a significant reduction in modification efficiency when nanoparticles are used directly. In practical applications, it is necessary to modify the surface of nanoparticles to avoid agglomeration and clumping, thereby improving their dispersibility and rheological properties.

[0004] The main compatibilization methods reported in relevant literature are as follows: (1) treating the surface of nano-silica; (2) adding an interfacial compatibilizer on the basis of surface treatment of nano-silica. The treatment methods for nano-silica include surface coating, adsorption modification, coupling agent treatment, surface grafting, etc. Nano-silica particles have a high hydroxyl content on their surface, which makes them easy to react with organic matter containing functional groups. If the organic matter has antioxidant and anti-aging properties, it can also endow the composite material with special properties such as anti-aging. Among them, the combination of coupling agent treatment and surface grafting of organic polymers is the current research hotspot. (China Plastics, 2012, 26, 11-16).

[0005] Commonly used coupling agents and grafted organic compounds include silane coupling agents and polymethyl methacrylate (PMMA), styrene monomer (St), and polybutyl acrylate (PBA), to prepare modified silica particles such as SiO2-g-PMMA, SiO2-g-St, and SiO2-g-PBA. Adding SiO2-g-PMMA to the PP matrix can effectively improve the tensile strength, flexural strength, and Rockwell hardness of PP, with better results than unmodified nano-SiO2. However, due to the poor impact toughness of PMMA, it significantly affects the impact performance of the matrix. Furthermore, after bonding with SiO2, it promotes heterogeneous nucleation in the product, resulting in a significant loss of toughness despite increased rigidity. In addition, PMMA is a casting material; compared to extrusion preparation, solvent bonding time is longer, bonding strength is lower, preparation costs are higher, and it is prone to cracking in solutions and chemicals. Common methods for toughening PP include blending with elastomers (POE, EMMA, etc.) or using crosslinking (DA reaction). However, these methods do not provide a good balance between the rigidity and toughness of the PP matrix, which is one of the important research and development directions for high-end PP products.

[0006] Patent 201610321080 discloses a method for preparing silica-modified polypropylene materials. The silica, after being modified with a silane coupling agent, reacts sequentially with an organic acid containing multiple hydroxyl groups (branching) and an alkyl acid without hydroxyl groups (end-capping) to organically modify the silica surface. The modified silica powder exhibits enhanced interfacial bonding with polypropylene, resulting in a composite material with excellent mechanical properties. However, this silica modification process requires a high-temperature environment (120-140℃), a nitrogen atmosphere, and a catalyst (p-toluenesulfonic acid), making the reaction conditions quite demanding.

[0007] Patent 201410151479 discloses a method for preparing high-flow, high-impact polypropylene. The raw materials include homopolymer polypropylene, ethylene-propylene block copolymer, and processing aids, which are mixed uniformly in a high-speed mixer. The mixture is then melt-extruded and granulated in a twin-screw extruder to obtain high-flow, high-impact polypropylene. However, this technology uses homopolymer polypropylene as the matrix resin, which does not contribute sufficiently to the impact performance of the composition, making it difficult to achieve a combined increase in melt flow rate (MFR) and impact strength. Furthermore, to further improve impact strength, the melt flow rate would be significantly affected.

[0008] Patent 201680053228 discloses a high-impact polypropylene-based blend. This technology improves impact resistance by introducing polystyrene or its copolymers into polypropylene resin, resulting in an blend with an impact strength higher than 25 kJ / m. 2 This technology introduces polystyrene into a polypropylene matrix. Since the two resins are completely incompatible systems, the blend suffers from severe phase separation, necessitating the introduction of graft copolymers as compatibilizers to improve the situation.

[0009] Patent CN111909482A discloses a modified high-temperature resistant polypropylene material and its preparation method. First, modified polypropylene is prepared by a multi-stage reaction of propylene monomer, styrene, acrylonitrile, maleic anhydride, and modified silica. Next, modified silica is prepared by β-cyclodextrin, silica, and dibutyltin dilaurate. Finally, glass fiber is added to further enhance the temperature resistance and strength of the polypropylene. The resulting resin exhibits high temperature resistance and high mechanical strength. However, this method uses multiple modifiers, resulting in a complex preparation process. Furthermore, the dispersion of inorganic fillers such as silica and glass fiber in the matrix resin is difficult to control, leading to agglomeration and a decrease in mechanical properties. Summary of the Invention

[0010] In order to at least partially solve the above-mentioned technical problems existing in the prior art and to further enrich the modification methods for toughening and strengthening polyolefin materials, the present invention provides a polyolefin material with high strength and good rigidity-toughness balance, so as to be applicable to more and higher-end fields.

[0011] As one aspect of the present invention, a reinforced and toughened polyolefin material is provided, comprising the following raw materials by weight: 75-95 parts of modified polypropylene A, 1-20 parts of modified silica B, and 1-7 parts of additives.

[0012] The modified polypropylene A is modified with a grafted monomer, and the structural formula (Ⅰ) of the grafted monomer is:

[0013]

[0014] In formula (Ⅰ): X is a linear alkyl or saturated fatty alcohol group containing 1 to 10 carbon atoms, or does not contain X;

[0015] The modified silica B is surface-modified with cyclodextrin derivatives.

[0016] In one or more possible embodiments, the grafting monomer is styrene, and the styrene content in the modified polypropylene A is 0.2-3% by mass; the cyclodextrin derivative is a β-cyclodextrin derivative, and the β-cyclodextrin derivative content in the modified silica B is 0.5-5% by mass.

[0017] By adopting the above technical solution, the surface of modified silica B is composed of β-cyclodextrin (βCD) with inclusion properties. βCD has a special cyclic hollow cylindrical structure, with hydroxyl groups distributed at both ends and the outside of the cylinder, making it hydrophilic, while the inside of the cylinder is hydrophobic. The modified SiO2-g-βCD exhibits good dispersion ability in polypropylene materials due to its reduced surface tension. Simultaneously, the main chain of modified polypropylene A contains non-polar benzene ring side groups, which can enter the βCD cavity to crosslink the polypropylene molecular chains, strengthening the interfacial forces and resulting in a polyolefin material with excellent rigidity-toughness balance.

[0018] In one or more possible embodiments, the raw materials comprise, by weight, the following components: 88-95 parts modified polypropylene A, 5-7 parts modified silica B, and 4-5 parts additives.

[0019] The modified polypropylene A is obtained by modifying polypropylene with styrene, wherein the mass content of styrene in the modified polypropylene A is 0.2-3%;

[0020] The surface of the modified silica B is sequentially modified with a silane coupling agent and the β-cyclodextrin derivative, wherein the mass content of the β-cyclodextrin derivative in the modified silica B is 0.5-5%.

[0021] In one or more possible embodiments, the polypropylene is homopolymer polypropylene or copolymer polypropylene.

[0022] By adopting the above technical solutions, on the one hand, the dispersion of SiO2 particles in the matrix can be improved, and the increased dispersion can effectively enhance the stiffening performance of SiO2 particles on the polypropylene matrix; on the other hand, the introduction of cyclodextrin molecules causes the polypropylene molecular chains to undergo cross-linking reactions, effectively improving the toughness of the product; finally, the introduction of SiO2-g-βCD modified particles increases the heterogeneous nucleation sites in the polypropylene matrix under the synergistic effect of SiO2 and βCD, further enhancing the product strength.

[0023] In one or more possible embodiments, the melt flow rate (MFR) of the polypropylene is 30–110 g / 10 min.

[0024] In one or more possible embodiments, the copolymer polypropylene is selected from ethylene-propylene copolymers, and the ethylene monomer in the copolymer polypropylene has a mass content of 5-15%.

[0025] In one or more possible embodiments, the ethylene monomer content is 8-10 wt%.

[0026] In one or more possible embodiments, the copolymer polypropylene comprises an ethylene-propylene random copolymer, an ethylene-propylene block copolymer, and isotactic polypropylene; the mass content of the ethylene-propylene random copolymer is 8-24%; the mass content of the ethylene-propylene block copolymer is 3-11%; and the mass content of the isotactic polypropylene is 65-89%.

[0027] By adopting the above technical solutions, the rubber phase can ensure that the matrix resin has a certain impact strength; the compatibilizing phase can enhance the interaction force between the rubber phase and the resin matrix; and the isotactic phase can ensure the flexural modulus of the matrix resin.

[0028] In one or more possible embodiments, the particle size of the ethylene-propylene random copolymer particles is 0.05–4 μm, and the density is 1 × 10⁻⁶. 5 ~1×10 8 pcs / mm 3 .

[0029] In one or more possible embodiments, the silane coupling agent is selected from one or more of 3-glycidyl etheroxypropyltrimethoxysilane, 3-glycidyl etheroxypropyltriethoxysilane, 3-aminopropyltrimethoxysilane, and 3-aminopropyltriethoxysilane;

[0030] The derivative of the β-cyclodextrin is selected from one or more of hydroxyethyl-β-cyclodextrin, hydroxypropyl-β-cyclodextrin, amino-β-cyclodextrin, mercapto-β-cyclodextrin, carboxymethyl-β-cyclodextrin, and β-cyclodextrin.

[0031] In one or more possible embodiments, the adjuvant includes a halogen absorber and an antioxidant.

[0032] In one or more possible embodiments, the halogen absorbent is selected from one or more of hydrotalcite, calcium stearate, and zinc stearate.

[0033] In one or more possible embodiments, the antioxidant is a hindered phenolic antioxidant or a compound antioxidant;

[0034] The compound antioxidant includes a primary antioxidant and a co-antioxidant; wherein the mass ratio of the primary antioxidant to the co-antioxidant is 1:(1-2).

[0035] In one or more possible embodiments, the primary antioxidant is a hindered phenolic antioxidant; the co-antioxidant is a phosphite antioxidant.

[0036] As another aspect of the present invention, a method for preparing the above-mentioned reinforced and toughened polyolefin material is provided, the method comprising the following steps:

[0037] S1. According to the weight parts, add modified polypropylene A, modified silica B and additives in sequence, mix evenly to obtain the preform;

[0038] S2. The preform in S1 is extruded and granulated to obtain a polyolefin material.

[0039] In one or more possible embodiments, in S1, the preparation of the modified polypropylene A includes: mixing the polypropylene, the styrene, and the initiator to obtain a mixture of modified polypropylene A.

[0040] In one or more possible embodiments, the mixing temperature is set to 180–190°C, the rotation speed is set to 40–50 rpm, and the time is 5–10 min.

[0041] In one or more possible embodiments, in S1, the preparation of the modified silica B includes the following steps:

[0042] S11. Place nano-silica in an activation solution to obtain activated nano-silica;

[0043] S12. Add the activated nano-silica from S11 to a dilute acetic acid solution of silane coupling agent to obtain silane coupling agent modified nano-silica.

[0044] S13. The silane coupling agent-modified nano-silica obtained in S12 is placed in a buffer solution containing β-cyclodextrin derivative and mixed evenly to obtain modified silica B.

[0045] In one or more possible embodiments, in S11, the activation temperature of the activated nano-silica is 50-60°C, and the activation time is 1-2 hours.

[0046] In one or more possible embodiments, in S12, the mixing time of the activated nano-silica with the dilute acetic acid solution of the silane coupling agent is 2 to 4 hours.

[0047] In one or more possible embodiments, in S12, the mass ratio of the silane coupling agent to the activated nano-silica and the dilute acetic acid solution is (2-5):(5-10):100.

[0048] In one or more possible embodiments, in S12, the mass ratio of the β-cyclodextrin derivative to the silane coupling agent-modified nano-silica and the buffer solution is (2-5):(5-10):100.

[0049] In one or more possible embodiments, in S13, when the mixture is placed in a buffer solution containing a β-cyclodextrin derivative, the mixing temperature is set to 40–60°C and the mixing time is set to 2–4 h.

[0050] In one or more possible embodiments, in S2, the extrusion temperature is set to 170–210°C.

[0051] As another aspect of the present invention, the invention relates to the application of the aforementioned polyolefin material, which is used in the medical field as a pharmaceutical packaging material or in the automotive field as a thin-walled injection molded product.

[0052] This invention utilizes the inclusion effect of cyclodextrin derivatives on organic molecules. Through the host-guest reaction between the cylindrical β-cyclodextrin molecule and the benzene ring, the modified polypropylene molecular chain is cross-linked, which strengthens the interfacial interaction force and gives the polyolefin material excellent rigidity and toughness balance.

[0053] This invention improves the dispersion ability of silica particles in resin materials by introducing hydrophilic β-cyclodextrin derivatives as modifying materials, improves the agglomeration problem of filler particles in polymer materials, effectively enhances the stiffening performance of SiO2 particles on polypropylene (PP) matrix, and significantly improves the impact strength and flexural modulus of the product.

[0054] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained in accordance with the structures particularly pointed out in the description, claims and drawings. Attached Figure Description

[0055] Figure 1 This is a schematic diagram of the preparation process of modified SiO2; where 1) is the activation process; 2) is the modification step of silane coupling agent; and 3) is the modification step of cyclodextrin derivative.

[0056] Figure 2 This is a schematic diagram of the structure of a β-cyclodextrin derivative;

[0057] Figure 3 The infrared spectra of the three types of silica (SiO2) particles prepared in Example 1 are as follows: activated silica B1, silane coupling agent-modified silica B2, and cyclodextrin derivative-modified silica B. The infrared spectrum of activated silica B1 is shown in the SiO2 curve; the infrared spectrum of silane coupling agent-modified silica B2 is shown in the SiO2-GOPS curve; and the infrared spectrum of cyclodextrin derivative-modified silica B is shown in the SiO2-βCD curve.

[0058] Figure 4 The images are scanning electron microscope images of the polyolefin materials in Comparative Example 1 and Example 3; the left image represents Comparative Example 1 and the right image represents Example 3. Detailed Implementation

[0059] The present invention will be further described below with reference to specific embodiments. The scope of protection of the present invention is not limited to the following embodiments. The main sources of materials involved in the embodiments are shown in Table 1 below. Other materials not specified are all conventional commercially available products.

[0060] Table 1 Material Source Description

[0061]

[0062]

[0063] This invention uses a twin-screw extruder, model ZSE34, from Leistrize GmbH, Germany; the high-speed mixer used in this invention is model SHR-500A.

[0064] The polypropylene used in this invention is of the following five types:

[0065] Polypropylene 1: Copolymer polypropylene, MFR = 30 g / 10 min, with a comonomer ethylene content of 15% by mass, of which ethylene-propylene random copolymer accounts for 24% by mass, ethylene-propylene block copolymer accounts for 11% by mass, and isotactic polypropylene accounts for 65% by mass. The particle size of the ethylene-propylene random copolymer particles is 0.05–4 μm, and the particle density is 1 × 10⁻⁶. 8 pcs / mm 3 .

[0066] Polypropylene 2: Copolymer polypropylene, MFR = 40 g / 10 min, with a comonomer ethylene content of 10%, of which the ethylene-propylene random copolymer content is 17%, the ethylene-propylene block copolymer content is 7%, and the isotactic polypropylene content is 76%. The particle size of the ethylene-propylene random copolymer particles is 0.05–4 μm, and the particle density is 1 × 10⁻⁶. 7 pcs / mm 3 .

[0067] Polypropylene 3: Copolymer polypropylene, MFR = 50 g / 10 min, with a comonomer ethylene content of 8% by mass, of which ethylene-propylene random copolymer accounts for 14% by mass, ethylene-propylene block copolymer accounts for 5% by mass, and isotactic polypropylene accounts for 81% by mass. The particle size of the ethylene-propylene random copolymer particles is 0.05–4 μm, and the particle density is 1 × 10⁻⁶. 6 pcs / mm 3 .

[0068] Polypropylene 4: Copolymer polypropylene, MFR = 110 g / 10 min, with a comonomer ethylene content of 5% by mass, of which ethylene-propylene random copolymer accounts for 8% by mass, ethylene-propylene block copolymer accounts for 3% by mass, and isotactic polypropylene accounts for 89% by mass. The particle size of the ethylene-propylene random copolymer particles is 0.05–4 μm, and the particle density is 1 × 10⁻⁶. 5 pcs / mm 3 .

[0069] Polypropylene 5: Homopolymer polypropylene, MFR = 50 g / 10 min.

[0070] In this embodiment of the invention, the preparation process and reaction conditions of some solutions are as follows:

[0071] Activation solution: 30% hydrogen peroxide and concentrated sulfuric acid are mixed at a volume ratio of (2-3):6. The preparation process is exothermic. After cooling to room temperature, the activation solution is obtained.

[0072] Reaction solution: Add silane coupling agent dropwise to dilute acetic acid solution (acetic acid:water = (3~20):100, volume ratio), stir for 1 hour under nitrogen atmosphere to obtain reaction solution.

[0073] Buffer solution: The buffer solution is a mixed aqueous solution (pH 5.5) of 0.1M 4-morpholine ethanesulfonic acid, 0.01M 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.02M N-hydroxysuccinimide.

[0074] Granulation conditions: The extrusion temperature of the twin-screw extruder is set to 170-210℃ to obtain polyolefin materials.

[0075] The solution preparation process and reaction conditions are the same in all embodiments, and will not be repeated here.

[0076] To enhance and toughen polyolefin materials, the inventors conducted further research and development, resulting in Examples 1-8 as described below. The preparation process of modified silica B in the following examples is detailed in the appendix. Figure 1 See the attached diagram for the structural schematic of the β-cyclodextrin derivative used. Figure 2 .

[0077] Example 1

[0078] See attached document Figure 1 and attached Figure 2 The polyolefin material prepared in this embodiment includes the following steps:

[0079] (1) Add 99.3 parts of polypropylene 1, 0.2 parts of styrene monomer and 0.5 parts of di-tert-butyl peroxide to a mixer and run at 180°C and 40 rpm for 10 minutes to obtain modified polypropylene A;

[0080] (2) 20 parts of nano-silica were immersed in 80 parts of activation solution (hydrogen peroxide: concentrated sulfuric acid = 2:6, volume ratio) and reacted at 50°C for 2 hours to obtain activated silica B1. Activated silica B1 was immersed in a dilute acetic acid solution containing 3-glycidyl etheroxypropyltrimethoxysilane (wherein, the mass ratio of 3-glycidyl etheroxypropyltrimethoxysilane, activated silica B1 and dilute acetic acid solution is 2:5:100; the dilute acetic acid solution contains acetic acid:water = 3:100, volume ratio) and reacted at 23°C for 4 hours to obtain silane coupling agent modified silica B2. Silane coupling agent modified silica B2 was immersed in a buffer solution containing hydroxyethyl-β-cyclodextrin (wherein, the mass ratio of hydroxyethyl-β-cyclodextrin, silane coupling agent modified silica B2 and buffer solution is 2:5:100) and reacted at 40°C for 4 hours to obtain modified silica B.

[0081] (3) The above 95 parts of modified polypropylene A, 1 part of modified silica B, 2 parts of hydrotalcite, 1 part of antioxidant 1010 and 1 part of antioxidant 168 are mixed in a high-speed mixer (480 rpm) for 3 minutes and then extruded and granulated to obtain polyolefin material.

[0082] Example 2

[0083] See attached document Figure 1 and attached Figure 2 The polyolefin material prepared in this embodiment includes the following steps:

[0084] (1) Add 98.5 parts of polypropylene 2, 1.0 parts of styrene monomer and 0.5 parts of dicumyl peroxide to a mixer and run at 190°C and 50 rpm for 5 minutes to obtain modified polypropylene A.

[0085] (2) Immerse 20 parts of nano-silica in 80 parts of activation solution (hydrogen peroxide: concentrated sulfuric acid = 2:6, volume ratio) and react at 60°C for 1 hour to obtain activated silica B1. Immerse activated silica B1 in a dilute acetic acid solution containing 3-glycidyl etheroxypropyltriethoxysilane (wherein, the mass ratio of 3-glycidyl etheroxypropyltriethoxysilane, activated silica B1 and dilute acetic acid solution is 5:10:100; the dilute acetic acid solution contains acetic acid:water = 5:100, volume ratio) and react at 23°C for 2 hours to obtain silane coupling agent modified silica B2. Immerse silane coupling agent modified silica B2 in a buffer solution containing hydroxyethyl-β-cyclodextrin (wherein, the mass ratio of hydroxyethyl-β-cyclodextrin, silane coupling agent modified silica B2 and buffer solution is 5:10:100) and react at 60°C for 2 hours to obtain modified silica B.

[0086] (3) The above 93 parts of modified polypropylene A, 3 parts of modified silica B, 1 part of calcium stearate, 1 part of zinc stearate and 2 parts of antioxidant 1010 are mixed in a high-speed mixer (480 rpm) for 3 minutes and then extruded and granulated to obtain polyolefin material.

[0087] Example 3

[0088] See attached document Figure 1 and attached Figure 2 The polyolefin material prepared in this embodiment includes the following steps:

[0089] (1) Add 98 parts of polypropylene 3, 1.5 parts of styrene monomer and 0.5 parts of di-tert-butyl peroxide to a mixer and run at 180°C and 40 rpm for 10 minutes to obtain modified polypropylene A;

[0090] (2) Immerse 20 parts of nano-silica in 80 parts of activation solution (hydrogen peroxide: concentrated sulfuric acid = 2:6, volume ratio) and react at 50°C for 2 hours to obtain activated silica B1. Immerse activated silica B1 in a dilute acetic acid solution containing 3-glycidyl etheroxypropyltrimethoxysilane (wherein, the mass ratio of 3-glycidyl etheroxypropyltrimethoxysilane, activated silica B1 and dilute acetic acid solution is 2:5:100; the dilute acetic acid solution contains acetic acid:water = 5:100, volume ratio... The silica modified with silane coupling agent was reacted at 23°C for 4 hours to obtain silica B2. The silica modified with silane coupling agent was then immersed in a buffer solution containing a mixture of hydroxypropyl-β-cyclodextrin, hydroxyethyl-β-cyclodextrin and amino-β-cyclodextrin (wherein the mass ratio of the mixture of hydroxypropyl-β-cyclodextrin, hydroxyethyl-β-cyclodextrin and amino-β-cyclodextrin, silica modified with silane coupling agent and buffer solution was 2:5:100) and reacted at 40°C for 4 hours to obtain modified silica B.

[0091] (3) The above 90 parts of modified polypropylene A, 5 parts of modified silica B, 2 parts of calcium stearate, 1 part of antioxidant 1010 and 2 parts of antioxidant 168 are mixed in a high-speed mixer (480 rpm) for 3 minutes and then extruded and granulated to obtain polyolefin material.

[0092] Example 4

[0093] See attached document Figure 1 and attached Figure 2 The polyolefin material prepared in this embodiment includes the following steps:

[0094] (1) Add 98 parts of polypropylene 3, 1.5 parts of styrene monomer and 0.5 parts of dicumyl peroxide to a mixer and run at 190°C and 50 rpm for 5 minutes to obtain modified polypropylene A.

[0095] (2) Immerse 20 parts of nano-silica in 80 parts of activation solution (hydrogen peroxide: concentrated sulfuric acid = 3:6, volume ratio) and react at 60°C for 1 hour to obtain activated silica B1. Immerse activated silica B1 in a dilute acetic acid solution containing 3-glycidyl etheroxypropyltrimethoxysilane (wherein, the mass ratio of 3-glycidyl etheroxypropyltrimethoxysilane, activated silica B1 and dilute acetic acid solution is 5:10:100; the dilute acetic acid solution contains acetic acid:water = 10:100, volume ratio) and react at 23°C for 2 hours to obtain silane coupling agent modified silica B2. Immerse silane coupling agent modified silica B2 in a buffer solution containing mercapto-β-cyclodextrin (wherein, the mass ratio of mercapto-β-cyclodextrin, silane coupling agent modified silica B2 and buffer solution is 5:10:100) and react at 60°C for 2 hours to obtain modified silica B.

[0096] (3) The above 90 parts of modified polypropylene A, 5 parts of modified silica B, 2 parts of calcium stearate, 1 part of antioxidant 1010 and 2 parts of antioxidant 168 are mixed in a high-speed mixer (480 rpm) for 3 minutes and then extruded and granulated to obtain polyolefin material.

[0097] Example 5

[0098] See attached document Figure 1 and attached Figure 2 The polyolefin material prepared in this embodiment includes the following steps:

[0099] (1) Add 98 parts of polypropylene 3, 1.5 parts of styrene monomer and 0.5 parts of di-tert-butyl peroxide to a mixer and run at 180°C and 40 rpm for 10 minutes to obtain modified polypropylene A;

[0100] (2) Immerse 20 parts of nano-silica in 80 parts of activation solution (hydrogen peroxide: concentrated sulfuric acid = 3:6, volume ratio) and react at 50°C for 2 hours to obtain activated silica B1. Immerse activated silica B1 in a dilute acetic acid solution containing 3-glycidyl etheroxypropyltrimethoxysilane (wherein, the mass ratio of 3-glycidyl etheroxypropyltrimethoxysilane, activated silica B1 and dilute acetic acid solution is 2:5:100; the dilute acetic acid solution contains acetic acid:water = 5:100, volume ratio) and react at 23°C for 4 hours to obtain silane coupling agent modified silica B2. Immerse silane coupling agent modified silica B2 in a buffer solution containing amino-β-cyclodextrin (wherein, the mass ratio of amino-β-cyclodextrin, silane coupling agent modified silica B2 and buffer solution is 2:5:100) and react at 40°C for 4 hours to obtain modified silica B.

[0101] (3) The above 92 parts of modified polypropylene A, 7 parts of modified silica B, 0.4 parts of calcium stearate, 0.2 parts of antioxidant 1010 and 0.4 parts of antioxidant 168 were mixed in a high-speed mixer (480 rpm) for 3 minutes and then extruded and granulated to obtain polyolefin material.

[0102] Example 6

[0103] See attached document Figure 1 and attached Figure 2 The polyolefin material prepared in this embodiment includes the following steps:

[0104] (1) Add 96.5 parts of polypropylene 4, 3.0 parts of styrene monomer and 0.5 parts of dicumyl peroxide to a mixer and run at 190°C and 50 rpm for 5 minutes to obtain modified polypropylene A.

[0105] (2) Immerse 20 parts of nano-silica in 80 parts of activation solution (hydrogen peroxide: concentrated sulfuric acid = 2:6, volume ratio) and react at 60°C for 1 hour to obtain activated silica B1. Immerse activated silica B1 in a dilute acetic acid solution containing 3-glycidyl etheroxypropyltrimethoxysilane (wherein, the mass ratio of 3-glycidyl etheroxypropyltrimethoxysilane, activated silica B1 and dilute acetic acid solution is 5:10:100; the acetic acid:water ratio in the dilute acetic acid solution is... The silica modified with silane coupling agent was obtained by reacting at 23°C for 2 hours with a volume ratio of 5:100 to 100. The silica modified with silane coupling agent was then immersed in a buffer solution containing a mixture of hydroxypropyl-β-cyclodextrin and hydroxyethyl-β-cyclodextrin (wherein the mass ratio of the mixture of hydroxypropyl-β-cyclodextrin and hydroxyethyl-β-cyclodextrin, silica modified with silane coupling agent and buffer solution was 5:10:100) and reacted at 60°C for 2 hours to obtain modified silica B.

[0106] (3) The above 88 parts of modified polypropylene A, 7 parts of modified silica B, 2 parts of calcium stearate and 3 parts of antioxidant 1010 are mixed in a high-speed mixer (480 rpm) for 3 minutes and then extruded and granulated to obtain polyolefin material.

[0107] Example 7

[0108] See attached document Figure 1 and attached Figure 2 The polyolefin material prepared in this embodiment includes the following steps:

[0109] (1) Add 96.5 parts of polypropylene 4, 3.0 parts of styrene monomer and 0.5 parts of di-tert-butyl peroxide to a mixer and run at 180°C and 40 rpm for 10 minutes to obtain modified polypropylene A;

[0110] (2) Immerse 20 parts of nano-silica in 80 parts of activation solution (hydrogen peroxide: concentrated sulfuric acid = 3:6, volume ratio) and react at 50°C for 2 hours to obtain activated silica B1. Immerse activated silica B1 in a dilute acetic acid solution containing 3-aminopropyltrimethoxysilane (wherein, the mass ratio of 3-aminopropyltrimethoxysilane, activated silica B1 and dilute acetic acid solution is 2:5:100; the dilute acetic acid solution contains acetic acid:water = 20:100, volume ratio) and react at 23°C for 4 hours to obtain silane coupling agent modified silica B2. Immerse silane coupling agent modified silica B2 in a buffer solution containing carboxymethyl-β-cyclodextrin (wherein, the mass ratio of carboxymethyl-β-cyclodextrin, silane coupling agent modified silica B2 and buffer solution is 2:5:100) and react at 40°C for 4 hours to obtain modified silica B.

[0111] (3) The above 86 parts of modified polypropylene A, 7 parts of modified silica B, 1 part of hydrotalcite, 1 part of calcium stearate, 1 part of zinc stearate, 2 parts of antioxidant 1010 and 2 parts of antioxidant 168 are mixed in a high-speed mixer (480 rpm) for 3 minutes and then extruded and granulated to obtain polyolefin material.

[0112] Example 8

[0113] See attached document Figure 1 and attached Figure 2 The polyolefin material prepared in this embodiment includes the following steps:

[0114] (1) Add 96.5 parts of polypropylene, 3.0 parts of styrene monomer and 0.5 parts of dicumyl peroxide to a mixer and run at 190°C and 50 rpm for 5 minutes to obtain modified polypropylene A.

[0115] (2) Immerse 20 parts of nano-silica in 80 parts of activation solution (hydrogen peroxide: concentrated sulfuric acid = 2:6, volume ratio) and react at 60°C for 1 hour to obtain activated silica B1. Immerse activated silica B1 in a dilute acetic acid solution containing 3-aminopropyltriethoxysilane (wherein, the mass ratio of 3-aminopropyltriethoxysilane, activated silica B1 and dilute acetic acid solution is 5:10:100; the dilute acetic acid solution contains acetic acid:water = 5:100, volume ratio) and react at 23°C for 2 hours to obtain silane coupling agent modified silica B2. Add silane coupling agent modified silica B2 to a buffer solution containing hydroxyethyl-β-cyclodextrin (wherein, the mass ratio of hydroxyethyl-β-cyclodextrin, silane coupling agent modified silica B2 and buffer solution is 5:10:100) and react at 60°C for 2 hours to obtain modified silica B.

[0116] (3) The above 75 parts of modified polypropylene A, 20 parts of modified silica B, 2 parts of calcium stearate, 1 part of antioxidant 1010 and 2 parts of antioxidant 168 are mixed in a high-speed mixer (480 rpm) for 3 minutes and then extruded and granulated to obtain polypropylene material.

[0117] When conducting experimental research, the inventors made comparative examples 1 to 7 by changing some of the set conditions.

[0118] Comparative Example 1

[0119] The difference from Example 3 is that no modified silica was added.

[0120] Comparative Example 2

[0121] The difference from Example 3 is that untreated nano-silica (nano-SiO2) was added.

[0122] Comparative Example 3

[0123] The difference from Example 3 is that the modified silica used was not modified with cyclodextrin derivatives;

[0124] Comparative Example 4

[0125] The difference from Example 8 is that the polypropylene used was not modified with styrene, and the polypropylene content was 99.5 parts.

[0126] Comparative Example 5

[0127] The difference from Example 8 is that the modified polypropylene used is prepared from 99.4 parts polypropylene 5, 0.1 parts styrene monomer and 0.5 parts di-tert-butyl peroxide.

[0128] Comparative Example 6

[0129] The difference from Example 8 is that the modified polypropylene used is prepared from 94.5 parts polypropylene, 5 parts styrene monomer and 0.5 parts di-tert-butyl peroxide.

[0130] Comparative Example 7

[0131] The SiO2-g-PMMA hybrid particles prepared in this comparative example were prepared in accordance with the article "Lu Ping. Preparation and performance study of SiO2-g-PMMA / PP nanocomposites [J]. Plastics Industry, 2010, 38(08):25-28." The specific operation is as follows:

[0132] The SiO2 nanoparticles used were alkylated and then further modified with PMMA. The preparation process is as follows: under stirring conditions, sodium dodecyl sulfate, emulsifier OP-10 and isopropanol were added to alkylated nano-SiO2 and deionized water. Then, MMA and an aqueous solution containing potassium persulfate were simultaneously added dropwise to a four-necked flask. The reaction was carried out at 75℃ for 4 hours. After 4 hours, the temperature was raised to 90℃ and maintained for 30 minutes to obtain SiO2-g-PMMA hybrid particles.

[0133] Performance testing

[0134] The performance tests of Examples 1-8 and Comparative Examples 1-7 were performed as follows, and the test results are recorded in Table 1 below.

[0135] (1) Test 1: Flexural modulus test

[0136] The test was conducted according to the relevant standards and test procedures in GB / T9341-2008 "Determination of Flexural Properties of Plastics";

[0137] (2) Test the impact strength of a simply supported beam with notch

[0138] The test was conducted according to the relevant standards and test procedures in GB / T1043.1-2008 "Determination of Impact Properties of Simply Supported Plastic Beams";

[0139] (3) Three-load heat distortion temperature test

[0140] The determination was carried out in accordance with the relevant standards and test procedures in GB / T 1634.2-2019 "Determination of Deformation Temperature of Plastics under Load".

[0141] Table 1. Test results of polypropylene material properties

[0142]

[0143] Based on the performance test results of the polyolefin materials shown in Table 1, we can find that:

[0144] The composite material prepared by polypropylene modified with styrene monomer and silica nanoparticles modified with β-cyclodextrin derivatives exhibits excellent balance between stiffness and toughness. The resulting polyolefin material has a flexural modulus greater than 1200 MPa and a notched impact strength of a simply supported beam greater than 30 kJ / m. 2 When copolymer polypropylene is used as the polypropylene matrix resin in this invention, the product exhibits better impact resistance, with a notched impact strength of up to 50 kJ / m² for simply supported beams. 2 above.

[0145] Compared to Example 3, no silica particles were added in Comparative Example 1, so there was no performance improvement. In Comparative Example 2, the silica particles were untreated and showed significant aggregation in the system, resulting in numerous defects in the composite material and a decrease in product performance compared to Comparative Example 1. In Comparative Example 3, the silica particles were not modified with cyclodextrin derivatives, therefore they could not undergo a crosslinking reaction with modified polypropylene A to improve product performance, but the dispersion of silica in the system was slightly improved, resulting in a slight increase in flexural modulus. Compared to Example 8, the resin matrix in Comparative Example 4 did not contain benzene rings, so no crosslinking reaction occurred in the system, and the notched impact strength of the resulting product was not improved. In Comparative Example 5, the amount of styrene monomer was too low, while in Comparative Example 6, the amount of styrene monomer was too high, resulting in a decrease in the corresponding mechanical properties compared to Example 8.

[0146] The inventors repeatedly verified this phenomenon through numerous experiments and concluded that: when the feed amount is less than 0.2%, the styrene monomer grafting rate is too low, which is not conducive to the crosslinking reaction and results in poorer impact performance of the product; when the feed amount is greater than 3%, the content of long-chain branches in the system increases, the melt index decreases significantly, which is not conducive to processing, and at this time the styrene self-polymerization rate increases, which is not conducive to the grafting reaction. However, by adopting the technical solution of this invention, the mass of the styrene is controlled to be 0.2-3.0% of the mass of the polypropylene. This is beneficial to the uniform distribution of styrene monomers on the copolymer polypropylene molecular chain, which is conducive to the subsequent crosslinking reaction with modified silica B, and improves the mechanical properties of the polypropylene resin under the condition of a slight decrease in melt flow rate.

[0147] Furthermore, in conjunction with the preparation steps of modified silica B in Example 1 and the appendix Figure 3 The infrared spectra of B1, B2, and B in the SiO2-GOPS sample show that the SiO2-GOPS sample has the highest infrared spectrum at 968 cm⁻¹. -1 A characteristic peak of epoxy groups appeared at 2932 cm⁻¹. -1 and 2855cm -1 Characteristic peaks for methyl and methylene groups appeared at 3423 cm⁻¹. -1 The characteristic peak of the stretching vibration of the hydroxyl group showed a significant decrease, indicating that the silane coupling agent bonded to some of the hydroxyl groups, resulting in the grafting of epoxy groups onto SiO2; after modification with cyclodextrin derivatives, the peak at 968 cm⁻¹... -1 The characteristic peak at 1625 cm⁻¹ weakens, indicating that the epoxide group has undergone a ring-opening reaction. -1 The peak at 3423 cm⁻¹ represents the stretching vibration of a carbon-carbon double bond. -1 The enhanced stretching vibration peak of the hydroxyl group is due to the hydroxyl molecules on the surface of the cyclodextrin molecule, which enhances the absorption peak at this location. The above analysis shows that β-cyclodextrin is effectively grafted onto the surface of SiO2 particles.

[0148] Through Example 3 and Comparative Example 1, and in conjunction with the appendix Figure 4Scanning electron microscope images of medium-reinforced polypropylene before and after modification show that: in the unmodified resin material, the xylene-soluble cross-section of the rubber phase has large pores and a clear interface between the two phases; in the grafted sample, the rubber phase exhibits a uniform and fine pore structure with more core-shell structures, and the cross-sectional surface is irregular, indicating ductile fracture. The pore depth of the rubber phase is shallower, indicating that the content of rubber phase that can be etched by xylene is reduced. This suggests that cross-linking has enhanced the interfacial force between the two phases to a certain extent, resulting in high impact strength, no dispersion, stable overall performance, and a more uniform distribution of the rubber phase.

[0149] In summary, the inventors believe that the flexural modulus and simply supported beam impact strength of the reinforced impact-resistant polypropylene material prepared by adding modified silica nanoparticles are significantly higher than those of the unmodified sample with the same rubber phase content prepared in the comparative example. The increase in flexural modulus is attributed to the reinforcing effect of the modified particles on the homopolymer phase, while the increase in impact strength is mainly due to the modified particles located in the compatibilizing phase (between the homopolymer phase and the rubber phase) promoting the fusion of the two phases and enhancing the interaction force between them during processing. In addition, the results show that SiO2 has a stronger nucleation ability and a higher heat distortion temperature after graft modification, further confirming that the improved affinity between particles and the matrix is ​​conducive to improving the heterogeneous nucleation ability of particles.

[0150] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. All modifications or applications made in accordance with the above embodiments are within the scope of protection of this technical solution.

[0151] Although specific embodiments of the invention have been described in detail, those skilled in the art will understand that various modifications and substitutions can be made to those details based on all the teachings disclosed, and all such changes are within the scope of protection of this invention. The full scope of this invention is given by the appended claims and any equivalents thereof.

Claims

1. Reinforced toughened polyolefin material, characterized in that, By weight parts, including the following composition raw materials: modified polypropylene A 75~95 parts, modified nano-silica B 1~20 parts, auxiliary 1~7 parts; The modified polypropylene A is obtained by grafting styrene on polypropylene, and the mass content of the styrene in the modified polypropylene A is 0.2~3%; The surface of the modified nano-silica B is modified by silane coupling agent and β-cyclodextrin derivative in turn, and the mass content of the β-cyclodextrin derivative in the modified nano-silica B is 0.5~5%; The β-cyclodextrin derivative is selected from one or more of hydroxyethyl-β-cyclodextrin, hydroxypropyl-β-cyclodextrin, amino-β-cyclodextrin, sulfhydryl-β-cyclodextrin and carboxymethyl-β-cyclodextrin.

2. A reinforced toughened polyolefin material according to claim 1, characterised in that, By weight parts, including the following composition raw materials: modified polypropylene A 88~95 parts, modified nano-silica B 5~7 parts, auxiliary 4-5 parts.

3. The reinforced toughened polyolefin material according to claim 1, wherein, The polypropylene is homopolymer polypropylene or copolymer polypropylene.

4. A reinforced toughened polyolefin material according to claim 3, characterised in that, The melt flow rate of the polypropylene is 30~110 g / 10 min.

5. The reinforced toughened polyolefin material according to claim 3, wherein, The copolymer polypropylene is selected from ethylene-propylene copolymer, and the mass content of ethylene monomer in the copolymer polypropylene is 5~15%.

6. A reinforced toughened polyolefin material according to claim 5, characterised in that, The mass content of the ethylene monomer is 8~10%.

7. The reinforced toughened polyolefin material according to claim 1, wherein, The polypropylene comprises ethylene-propylene random copolymer, ethylene-propylene block copolymer and isotactic polypropylene; the mass content of the ethylene-propylene random copolymer is 8~24%; the mass content of the ethylene-propylene block copolymer is 3~11%; and the mass content of the isotactic polypropylene is 65~89%.

8. A reinforced toughened polyolefin material according to claim 7, characterised in that, The ethylene-propylene random copolymer has a particle size of 0.05 to 4 μm and a density of 1 x 10 5 ~1 x 10 8 -1 x 10 3 -3 g / mm.

9. A reinforced toughened polyolefin material according to claim 1 or 2, characterised in that, The silane coupling agent is selected from one or more of 3-glycidyloxypropyl trimethoxysilane, 3-glycidyloxypropyl triethoxysilane, 3-aminopropyl trimethoxysilane and 3-aminopropyl triethoxysilane.

10. A reinforced toughened polyolefin material according to claim 1 or 2, characterised in that, The auxiliary includes halogen absorbent and antioxidant.

11. A reinforced toughened polyolefin material according to claim 10, characterised in that, The halogen absorbent is selected from one or more of hydrotalcite, calcium stearate and zinc stearate.

12. The reinforced toughened polyolefin material according to claim 10, wherein, The antioxidant is hindered phenolic antioxidant or compounded antioxidant. In the compounded antioxidant, a main antioxidant and an auxiliary antioxidant are included, and the mass ratio of the main antioxidant to the auxiliary antioxidant is 1: (1~2).

13. A reinforced toughened polyolefin material according to claim 12, characterised in that, The main antioxidant is hindered phenolic antioxidant, and the auxiliary antioxidant is phosphite antioxidant.

14. A process for the preparation of a reinforced toughened polyolefin material as claimed in any one of claims 1 to 13, characterised in that, The preparation method comprises the following steps: S1, by weight parts, the modified polypropylene A, modified nano-silica B and auxiliary are sequentially added and uniformly mixed to obtain a preform; S2, the preform in S1 is extruded and granulated to prepare a polyolefin material.

15. A process for the preparation of a reinforced toughened polyolefin material according to claim 14, characterised in that, In S1, the preparation of the modified polypropylene A comprises: mixing the polypropylene, the styrene and the initiator to obtain a mixed material modified polypropylene A.

16. A process for the preparation of a reinforced toughened polyolefin material according to claim 15, characterised in that, The mixing temperature is set to 180~190℃, the rotation speed is set to 40~50 rpm, and the time is 5~10 min.

17. The method of making a reinforced toughened polyolefin material according to claim 14, wherein, In S1, the preparation of the modified nano-silica B comprises the following steps: S11, the nano-silica is placed in an activation solution to obtain activated nano-silica; S12, the activated nano-silica in S11 is added to a dilute acetic acid solution of silane coupling agent to obtain nano-silica modified by silane coupling agent; S13, the silane coupling agent modified nano-silica prepared in S12 is placed in a buffer solution containing a beta cyclodextrin derivative, mixed uniformly to prepare modified nano-silica B.

18. A process for the preparation of a reinforced toughened polyolefin material according to claim 17, characterised in that, In S11, the activation temperature of the activated nano-silica is 50-60 DEG C, and the activation time is 1-2 h.

19. The method of making a reinforced toughened polyolefin material according to claim 17, wherein, In S12, the mixing time of the activated nano-silica and the dilute acetic acid solution of the silane coupling agent is 2-4 h.

20. The method of making a reinforced toughened polyolefin material according to claim 17, wherein, In S12, the mass ratio of the silane coupling agent, the activated nano-silica and the dilute acetic acid solution is (2-5):(5-10):

100.

21. The method of making a reinforced toughened polyolefin material according to claim 17, wherein, In S13, the mass ratio of the beta cyclodextrin derivative, the silane coupling agent modified nano-silica and the buffer solution is (2-5):(5-10):

100.

22. The method of making a reinforced toughened polyolefin material according to claim 17, wherein, In S13, when placed in the buffer solution containing the beta cyclodextrin derivative, the mixing temperature is set to 40-60 DEG C, and the mixing time is set to 2-4 h.

23. The method of making a reinforced toughened polyolefin material according to claim 14, wherein, In S2, the extrusion temperature is set to 170-210 DEG C.

24. Use of a reinforced toughened polyolefin material as claimed in any one of claims 1 to 13, characterised in that, The reinforced and toughened polyolefin material is used as a medicinal liquid packaging material in the medical field or as a thin-walled injection molding product in the automotive field.

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