Polyethylene composite material as well as preparation method and application thereof

Abstract

The invention relates to the technical field of high polymer materials, in particular to a polyethylene composite material as well as a preparation method and application thereof. The material is prepared from the following raw materials in parts by weight: 60 to 80 parts of high-density polyethylene, 20 to 38 parts of modified polyurethane, 8 to 12 parts of shell powder modified fiber, 5 to 18 parts of ethylene propylene diene monomer, 5 to 10 parts of maleic anhydride modified copolymer, 2 to 8 parts of antioxidant, 3 to 9 parts of plasticizer, 6 to 10 parts of stabilizer and 5 to 15 parts of flame retardant. The maleic anhydride modified copolymer is prepared by copolymerizing maleic anhydride and a methyl methacrylate monomer under the initiation of alpha, alpha '-azodiisobutyronitrile. The prepared polyethylene composite material has good toughness, and by adding the modified polyurethane and maleic anhydride modified copolymer, the anti-aging performance of the polyethylene composite material is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and more particularly to a polyethylene composite material and a preparation method and application thereof. Background Art

[0002] Polyethylene composites are high-performance engineering materials composed of a polyethylene matrix and reinforcing materials (such as fibers, particles, etc.), with excellent mechanical properties, chemical resistance, and processing properties. Its basic definition is: polyethylene is used as a matrix, and its performance is improved by adding rigid fillers (such as fibers, nanoparticles, etc.). Common polyethylene composites include ultra-high molecular weight polyethylene (UHMWPE) fiber composites, which are widely used in military, aerospace and other fields due to their high specific strength and good resistance to chemical corrosion. In addition, polyethylene composites can also enhance their mechanical properties, heat resistance, and corrosion resistance by adding inorganic nanoparticles (such as calcium carbonate, montmorillonite, etc.).

[0003] Polyethylene composites are commonly used in the manufacture of plastic pipes, wires and cables, and containers. They can also be used to manufacture roller covers for mining belt conveyors, paving slabs, and insulation materials. Polyethylene composites also show broad application prospects in smart packaging, biomedicine, thermal management, and other fields.

[0004] However, the molecular chains of polyethylene materials have weak interactions, which can lead to interfacial fracture or debonding when the composite material is subjected to stress, thereby reducing its mechanical properties. Polyethylene composites are also susceptible to ultraviolet rays and oxidation, and age quickly. Summary of the Invention

[0005] The present invention provides a polyethylene composite material, a preparation method and an application thereof. The prepared polyethylene composite material has good toughness. By adding modified polyurethane and maleic anhydride modified copolymer, the anti-aging performance of the polyethylene composite material is improved.

[0006] In a first aspect, the present invention provides a polyethylene composite material, which is composed of the following raw materials in parts by weight: 60-80 parts of high-density polyethylene, 20-38 parts of modified polyurethane, 8-12 parts of shell powder modified fiber, 5-18 parts of EPDM rubber, 5-10 parts of maleic anhydride modified copolymer, 2-8 parts of antioxidant, 3-9 parts of plasticizer, 6-10 parts of stabilizer, and 5-15 parts of flame retardant; the maleic anhydride modified copolymer is prepared by copolymerizing maleic anhydride and methyl methacrylate monomer under the initiation of α,α′-azobisisobutyronitrile.

[0007] Preferably, the mass ratio of the maleic anhydride to the methyl methacrylate monomer is 1-5:2-3.

[0008] Preferably, the modified polyurethane is obtained by chain extension with toluene diisocyanate, 2,2-dimethylolpropionic acid, polyε-caprolactone diol, N-aminoethyl-γ-aminopropyltriethoxysilane, and ethylenediamine, and stirred for reaction; the mass ratio of the toluene diisocyanate, 2,2-dimethylolpropionic acid, polyε-caprolactone diol and N-aminoethyl-γ-aminopropyltriethoxysilane is 1-3:2-3:1-2:1-7.

[0009] Preferably, the shell powder modified fiber is prepared by pretreating the shell powder with sodium stearate and then mixing it with glass fiber, and the mass ratio of the shell powder to the glass fiber is 1-5:1-2.

[0010] Preferably, the antioxidant is one or more of poly(dicyclopentadiene)-co-p-cresol, pentaerythritol tetrakis[β-(3',5',8,8-tetra-tert-butyl-4-hydroxyphenyl)propionate], tris(2,4-di-tert-butylphenyl) phosphite and carbon black.

[0011] Preferably, the plasticizer is one or more of dibutyl phthalate, dioctyl phthalate, dioctyl adipate, butyl cyclohexane, citrate, epoxy soybean oil and polycaprolactone.

[0012] Preferably, the stabilizer is one or more of calcium stearate, zinc stearate, tris(nonylphenyl)phosphite and tris(alkylaryl)phosphate.

[0013] Preferably, the flame retardant is one or more of zinc borate, antimony trioxide, aluminum hydroxide or decabromodiphenyl ether.

[0014] In a second aspect, the present invention provides a method for preparing a polyethylene composite material, comprising the following steps:

[0015] (1) high-density polyethylene is plasticized and melted on an open mill, and then an antioxidant, modified polyurethane, and shell powder modified fiber are added in sequence, and ethylene propylene diene monomer rubber is added after sufficient mixing to obtain a composite material base material for standby use;

[0016] (2) allowing the composite material base material obtained in step (1) to stand at room temperature for 12-24 hours, adding a plasticizer and a flame retardant at 80-100° C., and introducing the obtained composite material into a cold mixer for cooling to obtain a composite material base material;

[0017] (3) The pH of the composite material base material in step (2) is adjusted to 7, a stabilizer is added, the mixture is stirred evenly, and ultrasonicated to obtain a polyethylene composite material.

[0018] In a third aspect, the present invention provides an application of a polyethylene composite material in a thermal insulation material.

[0019] In summary, the present invention has the following beneficial effects:

[0020] 1. The present invention incorporates modified polyurethane and maleic anhydride-modified copolymers. The maleic anhydride-modified copolymer significantly improves the performance of the polymer matrix through the introduction of functional groups and a copolymerization mechanism. First, maleic anhydride itself has highly reactive anhydride groups that can chemically react with other functional groups in the polymer matrix (such as hydroxyl, amino, and carboxyl groups) to form covalent bonds, thereby enhancing the material's compatibility and interfacial adhesion. This reactivity not only improves the material's mechanical properties but also enhances its heat resistance and processing properties. The modifier is introduced into the polyurethane molecular chain through a chemical reaction, forming chemical bonds and thus enhancing its performance. The modified polyurethane itself has a good toughening effect, and the addition of maleic anhydride-grafted polypropylene further enhances the toughening effect of polyurethane on polypropylene. Maleic anhydride-grafted polypropylene forms a "core-shell" structure with the polyurethane, improving the material's impact toughness. Furthermore, maleic anhydride-grafted polypropylene can also improve the interfacial bonding between glass fiber and polypropylene, enhancing the mechanical properties of the composite material. The synergistic effects of maleic anhydride-modified copolymers and modified polyurethanes in polypropylene composites are primarily achieved through enhanced interfacial compatibility, improved mechanical properties, optimized crystallization behavior, synergistic toughening, and improved thermal stability and oxidation resistance. These synergistic effects significantly enhance the composites' performance in multiple areas.

[0021] 2. The shell powder-modified fiber of the present invention undergoes surface modification treatment to improve the compatibility and dispersibility between the shell powder and the polymer material polyethylene, thereby improving the mechanical properties and functional characteristics of the composite material. The modified shell powder can effectively improve the toughness of the composite material. Through surface modification and dispersibility optimization, the shell powder-modified fiber significantly improves the mechanical properties of the polypropylene composite material, including enhanced toughness, increased elongation at break, improved dispersibility, and enhanced interfacial bonding.

[0022] 3. The polyethylene composite material prepared by the present invention has good toughness. By adding modified polyurethane and maleic anhydride modified copolymer, the anti-aging performance of the polyethylene composite material is improved.

[0023] It should be understood that the above general description and the following detailed description are merely exemplary and explanatory and are not intended to limit the scope of protection of the present invention. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below with reference to the examples. It is particularly noted that if no specific conditions are specified in the following examples, the reactions were carried out according to conventional conditions or the conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following examples can be obtained from common commercial sources.

[0025] Example

[0026] Example 1

[0027] A polyethylene composite material is composed of the following raw materials in parts by weight: 60 parts of high-density polyethylene, 20 parts of modified polyurethane, 8 parts of shell powder modified fiber, 5 parts of EPDM rubber, 5 parts of maleic anhydride modified copolymer, 2 parts of antioxidant, 3 parts of plasticizer, 6 parts of stabilizer, and 5 parts of flame retardant; the maleic anhydride modified copolymer is prepared by copolymerizing maleic anhydride and methyl methacrylate monomer under the initiation of α,α′-azobisisobutyronitrile; the mass ratio of maleic anhydride to methyl methacrylate monomer is 1:2.

[0028] The modified polyurethane is prepared by chain extension and stirring reaction of toluene diisocyanate, 2,2-dimethylolpropionic acid, polyε-caprolactone diol, N-aminoethyl-γ-aminopropyltriethoxysilane, and ethylenediamine; the mass ratio of toluene diisocyanate, 2,2-dimethylolpropionic acid, polyε-caprolactone diol, and N-aminoethyl-γ-aminopropyltriethoxysilane is 1:2:1:1.

[0029] The shell powder modified fiber is prepared by pretreating the shell powder with sodium stearate and then mixing it with glass fiber. The mass ratio of the shell powder to the glass fiber is 1:2.

[0030] The antioxidant is poly(dicyclopentadiene)-co-p-cresol; the plasticizer is dibutyl phthalate; the stabilizer is calcium stearate; and the flame retardant is zinc borate.

[0031] A method for preparing a polyethylene composite material comprises the following steps:

[0032] (1) high-density polyethylene is plasticized and melted on an open mill, and then an antioxidant, modified polyurethane, and shell powder modified fiber are added in sequence, and ethylene propylene diene monomer rubber is added after sufficient mixing to obtain a composite material base material for standby use;

[0033] (2) the composite material base material obtained in step (1) was allowed to stand at room temperature for 12 hours, a plasticizer and a flame retardant were added at 80° C., and the obtained composite material was introduced into a cold mixer for cooling to obtain a composite material base material;

[0034] (3) The pH of the composite material base material in step (2) is adjusted to 7, a stabilizer is added, the mixture is stirred evenly, and ultrasonicated to obtain a polyethylene composite material.

[0035] Example 2

[0036] A polyethylene composite material is composed of the following raw materials in parts by weight: 70 parts of high-density polyethylene, 28 parts of modified polyurethane, 9 parts of shell powder modified fiber, 15 parts of EPDM rubber, 8 parts of maleic anhydride modified copolymer, 6 parts of antioxidant, 7 parts of plasticizer, 8 parts of stabilizer, and 10 parts of flame retardant; the maleic anhydride modified copolymer is prepared by copolymerizing maleic anhydride and methyl methacrylate monomer under the initiation of α,α′-azobisisobutyronitrile; the mass ratio of maleic anhydride to methyl methacrylate monomer is 2:3.

[0037] The modified polyurethane is prepared by chain extension and stirring reaction of toluene diisocyanate, 2,2-dimethylolpropionic acid, polyε-caprolactone diol, N-aminoethyl-γ-aminopropyltriethoxysilane, and ethylenediamine; the mass ratio of toluene diisocyanate, 2,2-dimethylolpropionic acid, polyε-caprolactone diol, and N-aminoethyl-γ-aminopropyltriethoxysilane is 3:2:1:5.

[0038] The shell powder modified fiber is prepared by pretreating the shell powder with sodium stearate and then mixing it with glass fiber. The mass ratio of the shell powder to the glass fiber is 3:1.

[0039] The antioxidant is poly(dicyclopentadiene)-co-p-cresol; the plasticizer is dibutyl phthalate; the stabilizer is calcium stearate; and the flame retardant is zinc borate.

[0040] A method for preparing a polyethylene composite material comprises the following steps:

[0041] (1) high-density polyethylene is plasticized and melted on an open mill, and then an antioxidant, modified polyurethane, and shell powder modified fiber are added in sequence, and ethylene propylene diene monomer rubber is added after sufficient mixing to obtain a composite material base material for standby use;

[0042] (2) the composite material base material obtained in step (1) was allowed to stand at room temperature for 24 hours, a plasticizer and a flame retardant were added at 90° C., and the obtained composite material was introduced into a cold mixer for cooling to obtain a composite material base material;

[0043] (3) The pH of the composite material base material in step (2) is adjusted to 7, a stabilizer is added, the mixture is stirred evenly, and ultrasonicated to obtain a polyethylene composite material.

[0044] Example 3

[0045] A polyethylene composite material is composed of the following raw materials in parts by weight: 80 parts of high-density polyethylene, 38 parts of modified polyurethane, 12 parts of shell powder modified fiber, 18 parts of EPDM rubber, 10 parts of maleic anhydride modified copolymer, 8 parts of antioxidant, 9 parts of plasticizer, 10 parts of stabilizer, and 15 parts of flame retardant; the maleic anhydride modified copolymer is prepared by copolymerizing maleic anhydride and methyl methacrylate monomer under the initiation of α,α′-azobisisobutyronitrile; the mass ratio of maleic anhydride to methyl methacrylate monomer is 5:2.

[0046] The modified polyurethane is prepared by chain extension and stirring reaction of toluene diisocyanate, 2,2-dimethylolpropionic acid, polyε-caprolactone diol, N-aminoethyl-γ-aminopropyltriethoxysilane, and ethylenediamine; the mass ratio of toluene diisocyanate, 2,2-dimethylolpropionic acid, polyε-caprolactone diol, and N-aminoethyl-γ-aminopropyltriethoxysilane is 3:2:2:7.

[0047] The shell powder modified fiber is prepared by pretreating the shell powder with sodium stearate and then mixing it with glass fiber. The mass ratio of the shell powder to the glass fiber is 5:1.

[0048] The antioxidant is poly(dicyclopentadiene)-co-p-cresol; the plasticizer is dibutyl phthalate; the stabilizer is calcium stearate; and the flame retardant is zinc borate.

[0049] A method for preparing a polyethylene composite material comprises the following steps:

[0050] (1) high-density polyethylene is plasticized and melted on an open mill, and then an antioxidant, modified polyurethane, and shell powder modified fiber are added in sequence, and ethylene propylene diene monomer rubber is added after sufficient mixing to obtain a composite material base material for standby use;

[0051] (2) the composite material base material obtained in step (1) was allowed to stand at room temperature for 24 hours, a plasticizer and a flame retardant were added at 100° C., and the obtained composite material was introduced into a cold mixer for cooling to obtain a composite material base material;

[0052] (3) The pH of the composite material base material in step (2) is adjusted to 7, a stabilizer is added, the mixture is stirred evenly, and ultrasonicated to obtain a polyethylene composite material.

[0053] Comparative Example 1

[0054] A polyethylene composite material was prepared in the same manner as in Example 1, except that no modified polyurethane was added.

[0055] Comparative Example 2

[0056] A polyethylene composite material was prepared in the same manner as in Example 1, except that no maleic anhydride-modified copolymer was added.

[0057] Comparative Example 3

[0058] A polyethylene composite material was prepared in the same manner as in Example 1, except that no shell powder modified fiber was added.

[0059] Performance testing:

[0060] A xenon lamp aging box was used to simulate natural light, with a wavelength of 290-800nm ​​and an irradiance of 1200W / m 2 The black standard temperature is 65°C and the humidity is 65%, according to GB / T16422.2. The degree of aging is assessed by measuring the tensile strength and elongation at break retention. The flame retardancy of polyethylene composites is tested in a vertical combustion test according to GB / T2408.

[0061] Table 1 Performance test results

[0062]

[0063] As can be seen from Table 1, the polyethylene composite material prepared in Example 1 has good mechanical properties, anti-aging properties and flame retardant properties, which shows that the anti-aging properties of the polyethylene composite material are improved by adding modified polyurethane and maleic anhydride modified copolymer.

[0064] The above description is merely an exemplary embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A polyethylene composite material, characterized in that The invention is composed of the following raw materials in parts by weight: 60-80 parts of high-density polyethylene, 20-38 parts of modified polyurethane, 8-12 parts of shell powder modified fiber, 5-18 parts of EPDM rubber, 5-10 parts of maleic anhydride modified copolymer, 2-8 parts of antioxidant, 3-9 parts of plasticizer, 6-10 parts of stabilizer, and 5-15 parts of flame retardant; the maleic anhydride modified copolymer is prepared by copolymerizing maleic anhydride and methyl methacrylate monomer under the initiation of α,α′-azobisisobutyronitrile.

2. The polyethylene composite material according to claim 1, characterized in that The mass ratio of the maleic anhydride to the methyl methacrylate monomer is 1-5:2-3.

3. The polyethylene composite material according to claim 1, characterized in that The modified polyurethane is prepared by chain extension and stirring reaction of toluene diisocyanate, 2,2-dimethylol propionic acid, polyε-caprolactone diol, N-aminoethyl-γ-aminopropyltriethoxysilane, and ethylenediamine; the mass ratio of toluene diisocyanate, 2,2-dimethylol propionic acid, polyε-caprolactone diol, and N-aminoethyl-γ-aminopropyltriethoxysilane is 1-3:2-3:1-2:1-7.

4. The polyethylene composite material according to claim 1, characterized in that The shell powder modified fiber is prepared by pre-treating the shell powder with sodium stearate and then mixing the pre-treated shell powder with glass fiber. The mass ratio of the shell powder to the glass fiber is 1-5:1-2.

5. The polyethylene composite material according to claim 1, characterized in that: The antioxidant is one or more of poly(dicyclopentadiene)-co-p-cresol, pentaerythritol tetrakis[β-(3',5',8,8-tetra-tert-butyl-4-hydroxyphenyl)propionate, tris(2,4-di-tert-butylphenyl) phosphite and carbon black.

6. The polyethylene composite material according to claim 1, characterized in that The plasticizer is one or more of dibutyl phthalate, dioctyl phthalate, dioctyl adipate, butyl cyclohexane, citrate, epoxy soybean oil and polycaprolactone.

7. The polyethylene composite material according to claim 1, characterized in that: The stabilizer is one or more of calcium stearate, zinc stearate, tris(nonylphenyl)phosphite and tris(alkylaryl)phosphate.

8. The polyethylene composite material according to claim 1, characterized in that: The flame retardant is one or more of zinc borate, antimony trioxide, aluminum hydroxide or decabromodiphenyl ether.

9. The method for preparing the polyethylene composite material according to any one of claims 1 to 8, characterized in that: The following steps are involved: (1) high-density polyethylene is plasticized and melted on an open mill, and then an antioxidant, modified polyurethane, and shell powder modified fiber are added in sequence, and ethylene propylene diene monomer rubber is added after sufficient mixing to obtain a composite material base material for standby use; (2) allowing the composite material base material obtained in step (1) to stand at room temperature for 12-24 hours, adding a plasticizer and a flame retardant at 80-100° C., and introducing the obtained composite material into a cold mixer for cooling to obtain a composite material base material; (3) The pH of the composite material base material in step (2) is adjusted to 7, a stabilizer is added, the mixture is stirred evenly, and ultrasonicated to obtain a polyethylene composite material.

10. Use of the polyethylene composite material according to claim 1 in thermal insulation materials.

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