Composite material based on bio-based polyethylene and preparation method thereof

Abstract

The invention relates to a composite material based on bio-based polyethylene and a preparation method thereof, and belongs to the technical field of polymer composite materials. The composite material comprises the following components in parts by weight: 100 parts of bio-based polyethylene, 8-13 parts of an ethylene-octylene copolymer, 6.5-9.5 parts of a reinforcing aid, 90-100 parts of an inorganic metal flame retardant and 1.5-2 parts of a lubricant, the strengthening auxiliary agent is prepared by the following steps: carrying out amidation reaction on diallylamine and alkyl acyl chloride to prepare an alkylated monomer with an alkyl chain and a dialkenyl structure, and carrying out click addition on the alkylated monomer, dialkene and dithioglycol under initiation to form a macromolecular block polymer; after the composite material is blended and modified by the compound reinforcing aid, the toughness and comprehensive performance are remarkably improved, and meanwhile, good flame retardance is kept.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer composite materials, and in particular, relates to a composite material based on bio-based polyethylene and a preparation method thereof. Background Art

[0002] The main raw material of bio-based polyethylene is usually sucrose, which is converted into ethylene through fermentation and other chemical processes, and then further polymerized to form polyethylene, which is an environmentally friendly plastic material and can serve as a sustainable alternative to traditional petroleum-based polyethylene. In recent years, with the increasing attention to reducing plastic waste and lowering carbon footprint, the development and application of bio-based polyethylene has received widespread attention.

[0003] However, the molecular structure of bio-based polyethylene is different from the raw materials of petroleum-based polyethylene, resulting in different molecular states and properties of the final polymer, which leads to generally lower mechanical properties of bio-based polyethylene than petroleum-based polyethylene. In long-term studies, it was found that the difference in mechanical properties is related to the high content of unsaturated bonds in bio-based polyethylene. These unsaturated bonds are weak points in the molecular chain. They are more likely to break when subjected to external forces, resulting in a decrease in the overall performance of the material. The presence of unsaturated bonds will interrupt the continuity of the polyethylene molecular chain, reduce the effective interaction between the molecular chains, and thus reduce the mechanical strength of the material. Therefore, this application aims to improve the comprehensive mechanical properties of existing bio-based polyethylene materials. Summary of the invention

[0004] In order to solve the technical problems mentioned in the background technology, the purpose of the present invention is to provide a composite material based on bio-based polyethylene and a preparation method thereof.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] The composite material based on bio-based polyethylene comprises, by weight: 100 parts of bio-based polyethylene, 8-13 parts of ethylene-octene copolymer, 6.5-9.5 parts of reinforcing additive, 90-100 parts of inorganic metal flame retardant and 1.5-2 parts of lubricant.

[0007] The strengthening aid is prepared by the following method:

[0008] Step A1: diallylamine, anhydrous aluminum chloride and toluene are mixed, dry nitrogen is introduced for protection, the temperature is pre-raised to 50-75°C, stirring is applied at 60-90 rpm, alkyl acyl chloride is added intermittently for reaction for 3.5-5 hours, and then the temperature is continued to be raised to 110°C for reflux reaction for 1.2-1.8 hours. After the reaction is completed, toluene is removed by vacuum rotary evaporation to obtain an alkylated monomer;

[0009] Further, the amount ratio of diallylamine, alkyl acyl chloride, anhydrous aluminum chloride and toluene is 0.1 mol: 0.1 mol: 25-35 mg: 40-50 mL, and diallylamine and alkyl acyl chloride undergo an amidation reaction under the promotion of anhydrous aluminum chloride to form a compound having an alkyl chain and a diene structure;

[0010] Preferably, the alkyl chain length of the alkyl acyl chloride is C10-C18, and the introduction of alkyl chain blocks of this length into the molecular side chains of the reinforcing additive can have a good toughening effect on the polyethylene matrix.

[0011] Step A2: Mix the alkylated monomer, diene, ethanedithiol, photoinitiator TPO and dimethylacetamide, raise the temperature to 55-80°C, apply 90-120 rpm stirring and 150-200 W / m 2 The reaction was carried out under ultraviolet irradiation for 4-6 hours, and then tert-butyl perbenzoate was added and the temperature was continued to rise to 110-125°C and the reaction was continued for 1.5-2 hours. After the reaction was completed, the dimethylacetamide was removed by vacuum rotary evaporation, and the substrate was washed with water and dried to obtain a strengthening auxiliary agent;

[0012] Further, the amount ratio of the alkylated monomer, the diene, ethylenedithiol, the photoinitiator TPO, tert-butyl peroxybenzoate and dimethylacetamide is 10mmol: 60-80mmol: 0.1-0.12mol: 8-12mg: 5-10mg: 16-24mL, and the alkylated monomer and the diene are copolymerized with ethylenedithiol under light initiation and peroxide initiation;

[0013] Preferably, the diene is one or more of 1,5-hexadiene, 1,7-octadiene and 1,9-decadiene.

[0014] Furthermore, the inorganic metal flame retardant is compounded from magnesium hydroxide and aluminum hydroxide.

[0015] Furthermore, the lubricant is oxidized polyethylene wax.

[0016] The preparation method of the composite material based on bio-based polyethylene is specifically as follows: each raw material is mixed by a high-speed mixer, and the mixture is transferred to a twin-screw extruder for plasticization, extrusion and pelletization to obtain the composite material.

[0017] Furthermore, during the plasticizing extrusion process, the temperature zones of the twin-screw extruder are set as follows: zone one 170-180°C, zone two 180-190°C, zone three 190-195°C, and die head temperature 200°C.

[0018] Beneficial effects of the present invention:

[0019] The composite material disclosed in the present invention uses bio-based polyethylene as a matrix, and is compounded with a homemade reinforcing additive for blending and modification, thereby effectively improving the comprehensive performance of strength and toughness of the composite material.

[0020] The invention is based on the existing flame-retardant bio-based polyethylene system, and is compounded with a self-developed strengthening auxiliary agent for blending and modification, so that the comprehensive performance of the strength and toughness of the obtained composite material is significantly improved, while maintaining good flame retardancy; the strengthening auxiliary agent is prepared by amidation reaction of diallylamine and alkyl acyl chloride to form an alkylated monomer with an alkyl chain and a diene structure, which is click-added with a diene and ethanedithiol under initiation to form a macromolecular block polymer, and the macromolecular chain of the strengthening auxiliary agent is terminated by introducing active thiol groups with excessive ethanedithiol, and in the melt blending process, the terminal thiol groups of the strengthening auxiliary agent are further added to the residual unsaturated bonds in the bio-based polyethylene under a high temperature environment, playing a bridging role instead of a traditional cross-linking role, thereby avoiding a sharp decrease in the toughness of the composite material and improving the bio-based polyethylene. Molecular continuity is conducive to the improvement of mechanical properties. In addition, the nitrogen-containing sulfide structure is formed in the block chain of the alkylated monomer and ethanedithiol in the reinforcing agent, which has a chelating effect on the inorganic metal flame retardant, forming a force between the flame retardant and the polyethylene macromolecular chain, so that the flame retardant strengthens the macromolecular chain, which is conducive to improving the overall mechanical properties. At the same time, the reinforcing agent has a binding and fixing effect on the flame retardant to prevent the dripping of the burning material, so that the overall flame retardant performance is further improved. In addition, a large number of alkyl chains on the molecular side chains of the reinforcing agent are interspersed in the matrix on the surface of the assembly formed by the chelation of the flame retardant, which plays a good toughening role, compensating for the problem of reduced toughness caused by the introduction of inorganic metal flame retardants, so that the composite material has excellent comprehensive strength and toughness properties. DETAILED DESCRIPTION

[0021] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] Example 1, preparation of a composite material based on bio-based polyethylene, the specific implementation process is as follows:

[0023] (1) Preparation of strengthening additives

[0024] Step A1: Mix diallylamine, anhydrous aluminum chloride and toluene, introduce dry nitrogen protection, preheat to 50°C, apply stirring at 60rpm, intermittently add alkyl acyl chloride to react for 3.5h, then continue to heat to 110°C and reflux to react for 1.2h, wherein the alkyl acyl chloride is selected from decanoyl chloride with a carbon chain length of C10, and the amount ratio of diallylamine, alkyl acyl chloride, anhydrous aluminum chloride and toluene is 0.1mol: 0.1mol: 25mg: 40mL. After the reaction is completed, the toluene is quickly removed by reduced pressure rotary evaporation to obtain an alkylated monomer.

[0025] Step A2: Mix the alkylated monomer, diene, ethanedithiol, photoinitiator TPO and dimethylacetamide, raise the temperature to 55°C, apply 90 rpm stirring and 150 W / m 2 The reaction was carried out under ultraviolet irradiation for 4 hours, and then tert-butyl perbenzoate was added and the temperature was continued to rise to 110°C and the reaction was continued for 1.5 hours, wherein the diene was selected from 1,5-hexadiene, and the amount ratio of the alkylation monomer, the diene, ethanedithiol, the photoinitiator TPO, tert-butyl perbenzoate and dimethylacetamide was 10mmol:60mmol:0.1mol:8mg:5mg:16mL. After the reaction was completed, the dimethylacetamide was removed by reduced pressure rotary evaporation, and the substrate was washed with water and dried to obtain a strengthening auxiliary agent.

[0026] (2) Preparation of composite materials

[0027] Ingredients: The raw materials are calculated by weight: 100 parts of bio-based polyethylene, and STN7006 raw material is used in the implementation process; 13 parts of ethylene-octene copolymer, and 851L raw material is used in the implementation process; 6.5 parts of reinforcing additives are homemade in this embodiment; 90 parts of inorganic metal flame retardant, and magnesium hydroxide and aluminum hydroxide are compounded in a weight ratio of 10:1 in the implementation process; 1.5 parts of lubricant, and OA9 type oxidized polyethylene wax is used in the implementation process.

[0028] Granulation: Add all raw materials into a high-speed mixer and mix at 600 rpm for 10 minutes. Then transfer the mixture into a twin-screw extruder for plasticization, extrusion and pelletization. During this process, the temperature zones of the twin-screw extruder are set as follows: zone 1 is 170°C, zone 2 is 180°C, zone 3 is 190°C, and the die head temperature is 200°C to obtain a composite material based on bio-based polyethylene.

[0029] Example 2, preparation of a composite material based on bio-based polyethylene, the specific implementation process is as follows:

[0030] (1) Preparation of strengthening additives

[0031] Step A1: Mix diallylamine, anhydrous aluminum chloride and toluene, introduce dry nitrogen protection, preheat to 75°C, apply stirring at 90rpm, intermittently add alkyl acyl chloride to react for 5h, then continue to heat to 110°C and reflux to react for 1.8h, wherein the alkyl acyl chloride is selected from octadecanoyl chloride with a carbon chain length of C18, and the amount ratio of diallylamine, alkyl acyl chloride, anhydrous aluminum chloride and toluene is 0.1mol:0.1mol:35mg:50mL. After the reaction is completed, the toluene is quickly removed by reduced pressure rotary evaporation to obtain an alkylated monomer.

[0032] Step A2: Mix the alkylated monomer, diene, ethanedithiol, photoinitiator TPO and dimethylacetamide, raise the temperature to 80°C, apply stirring at 120 rpm and 200 W / m 2 The reaction was carried out under ultraviolet irradiation for 6 hours, and then tert-butyl perbenzoate was added and the temperature was continued to rise to 125°C and the reaction was continued for 2 hours, wherein the diene was selected from 1,9-decadiene, and the amount ratio of the alkylation monomer, the diene, ethanedithiol, the photoinitiator TPO, tert-butyl perbenzoate and dimethylacetamide was 10mmol:80mmol:0.12mol:12mg:10mg:24mL. After the reaction was completed, the dimethylacetamide was removed by reduced pressure rotary evaporation, and the substrate was washed with water and dried to obtain a strengthening auxiliary agent.

[0033] (2) Preparation of composite materials

[0034] Ingredients: The raw materials are calculated by weight: 100 parts of bio-based polyethylene, and STN7006 raw material is used in the implementation process; 8 parts of ethylene-octene copolymer, and 851L raw material is used in the implementation process; 9.5 parts of reinforcing additives are homemade in this embodiment; 100 parts of inorganic metal flame retardant, and magnesium hydroxide and aluminum hydroxide are compounded in a weight ratio of 10:1 in the implementation process; 2 parts of lubricant, and OA9 type oxidized polyethylene wax is used in the implementation process.

[0035] Granulation: Add all raw materials into a high-speed mixer and mix at 600 rpm for 10 minutes. Then transfer the mixture into a twin-screw extruder for plasticization, extrusion and pelletization. During this process, the temperature zones of the twin-screw extruder are set as follows: zone 1 is 180°C, zone 2 is 190°C, zone 3 is 195°C, and the die head temperature is 200°C to obtain a composite material based on bio-based polyethylene.

[0036] Example 3, preparation of a composite material based on bio-based polyethylene, the specific implementation process is as follows:

[0037] (1) Preparation of strengthening additives

[0038] Step A1: Mix diallylamine, anhydrous aluminum chloride and toluene, introduce dry nitrogen protection, preheat to 65°C, apply stirring at 90rpm, intermittently add alkyl acyl chloride to react for 4h, then continue to heat to 110°C and reflux for 1.5h, wherein the alkyl acyl chloride is selected from tetradecanoyl chloride with a carbon chain length of C14, and the amount ratio of diallylamine, alkyl acyl chloride, anhydrous aluminum chloride and toluene is 0.1mol:0.1mol:30mg:45mL. After the reaction is completed, the toluene is quickly removed by reduced pressure rotary evaporation to obtain an alkylated monomer.

[0039] Step A2: Mix the alkylated monomer, diene, ethanedithiol, photoinitiator TPO and dimethylacetamide, raise the temperature to 70°C, apply stirring at 120 rpm and 180 W / m 2 The reaction was carried out under ultraviolet irradiation for 5 hours, and then tert-butyl perbenzoate was added and the temperature was continued to rise to 115°C and the reaction was continued for 1.8 hours, wherein the diene was selected from 1,7-octadiene, and the amount ratio of the alkylation monomer, the diene, ethanedithiol, the photoinitiator TPO, tert-butyl perbenzoate and dimethylacetamide was 10mmol:70mmol:0.1mol:10mg:8mg:20mL. After the reaction was completed, the dimethylacetamide was removed by reduced pressure rotary evaporation, and the substrate was washed with water and dried to obtain a strengthening auxiliary agent.

[0040] (2) Preparation of composite materials

[0041] Ingredients: The raw materials are calculated by weight: 100 parts of bio-based polyethylene, and STN7006 raw material is used in the implementation process; 11 parts of ethylene-octene copolymer, and 851L raw material is used in the implementation process; 7.5 parts of reinforcing additives are homemade in this embodiment; 95 parts of inorganic metal flame retardant, and magnesium hydroxide and aluminum hydroxide are compounded in a weight ratio of 10:1 in the implementation process; 1.8 parts of lubricant, and OA9 type oxidized polyethylene wax is used in the implementation process.

[0042] Granulation: Add all raw materials into a high-speed mixer and mix at 600 rpm for 10 minutes. Then transfer the mixture into a twin-screw extruder for plasticization, extrusion and pelletization. During this process, the temperature zones of the twin-screw extruder are set as follows: zone 1 is 175°C, zone 2 is 180°C, zone 3 is 190°C, and the die head temperature is 200°C to obtain a composite material based on bio-based polyethylene.

[0043] Example 4, preparation of a composite material based on bio-based polyethylene, the specific implementation process is as follows:

[0044] (1) Preparation of strengthening additives

[0045] Step A1: Mix diallylamine, anhydrous aluminum chloride and toluene, introduce dry nitrogen protection, preheat to 60°C, apply stirring at 90rpm, intermittently add alkyl acyl chloride to react for 4.5h, then continue to heat to 110°C and reflux to react for 1.4h, wherein the alkyl acyl chloride is selected from dodecanoyl chloride with a carbon chain length of C12, and the amount ratio of diallylamine, alkyl acyl chloride, anhydrous aluminum chloride and toluene is 0.1mol: 0.1mol: 28mg: 45mL. After the reaction is completed, the toluene is quickly removed by reduced pressure rotary evaporation to obtain an alkylated monomer.

[0046] Step A2: Take the alkylated monomer, diene, ethanedithiol, photoinitiator TPO and dimethylacetamide and mix them, raise the temperature to 75°C, apply 120 rpm stirring and 200 W / m 2 The reaction was carried out under ultraviolet irradiation for 5.5 hours, and then tert-butyl perbenzoate was added and the temperature was continued to rise to 120°C and the reaction was continued for 1.6 hours, wherein the diene was selected from 1,5-hexadiene and 1,7-octadiene and premixed in an equimolar ratio, and the amount ratio of the alkylation monomer, diene, ethanedithiol, photoinitiator TPO, tert-butyl perbenzoate and dimethylacetamide was 10mmol:70mmol:0.11mol:11mg:7mg:22mL. After the reaction was completed, the dimethylacetamide was removed by reduced pressure rotary evaporation, and the substrate was washed with water and dried to obtain a reinforcing auxiliary agent.

[0047] (2) Preparation of composite materials

[0048] Ingredients: The raw materials are calculated by weight: 100 parts of bio-based polyethylene, and STN7006 raw material is used in the implementation process; 11 parts of ethylene-octene copolymer, and 851L raw material is used in the implementation process; 8 parts of reinforcing additives are homemade in this embodiment; 35 parts of inorganic metal flame retardant, and magnesium hydroxide and aluminum hydroxide are compounded in a weight ratio of 10:1 in the implementation process; 1.7 parts of lubricant, and OA9 type oxidized polyethylene wax is used in the implementation process.

[0049] Granulation: Add all raw materials into a high-speed mixer and mix at 600 rpm for 10 minutes. Then transfer the mixture into a twin-screw extruder for plasticization, extrusion and pelletization. During this process, the temperature zones of the twin-screw extruder are set as follows: zone 1 at 170°C, zone 2 at 185°C, zone 3 at 195°C, and die head temperature at 200°C to obtain a composite material based on bio-based polyethylene.

[0050] Comparative Example 1

[0051] This comparative example refers to Example 4, except that no reinforcing agent is added to the raw materials of the composite material, and the rest of the implementation process is exactly the same.

[0052] Comparative Example 2

[0053] This comparative example refers to Example 4, except that the reinforcing agent is replaced with 1.1 parts of silane coupling agent KH-580 and 6 parts of B20 type polybutadiene toughening agent, and the rest of the implementation process is exactly the same.

[0054] In order to test the relevant properties of the composite material, the composite material was hot pressed into a sheet using a flat vulcanizer, the hot pressing temperature was 200°C, the hot pressing pressure was 5MPa, and the sheet thickness was 3.2mm;

[0055] Samples were taken from the above sheets, and the tensile test was carried out according to ASTM D638-22 standard, the impact test was carried out according to ASTM D256-10 standard, and the flame retardant test was carried out according to UL94 standard. The specific test results are shown in Table 1:

[0056] Table 1

[0057]

[0058] It can be seen from the test results in Table 1 that the composite material prepared in the example has more excellent comprehensive properties of strength and toughness, and has good flame retardancy in the compounding system of inorganic metal flame retardant.

[0059] In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0060] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A composite material based on bio-based polyethylene, characterized in that The composition comprises, by weight: 100 parts of bio-based polyethylene, 8-13 parts of ethylene-octene copolymer, 6.5-9.5 parts of reinforcing agent, 90-100 parts of inorganic metal flame retardant and 1.5-2 parts of lubricant; The strengthening aid is prepared by the following method: Step A1: diallylamine, anhydrous aluminum chloride and toluene are mixed, dry nitrogen is introduced for protection, the temperature is pre-raised to 50-75°C, and alkyl acyl chloride is added intermittently with stirring for 3.5-5h, and then the temperature is continued to be raised to 110°C for reflux reaction for 1.2-1.8h. After the reaction is completed, toluene is removed by vacuum rotary evaporation to obtain an alkylated monomer; Step A2: Mix the alkylated monomer, diene, ethanedithiol, photoinitiator TPO and dimethylacetamide, raise the temperature to 55-80°C, stir and apply 150-200W / m 2 The reaction was carried out under ultraviolet irradiation for 4-6 hours, and then tert-butyl perbenzoate was added and the temperature was continued to rise to 110-125°C for reaction for 1.5-2 hours. After the reaction was completed, dimethylacetamide was removed by vacuum rotary evaporation, and the substrate was washed with water and dried to obtain a strengthening auxiliary agent.

2. The bio-based polyethylene composite material according to claim 1, characterized in that The usage ratio of diallylamine, alkyl acyl chloride, anhydrous aluminum chloride and toluene is 0.1 mol: 0.1 mol: 25-35 mg: 40-50 mL.

3. The bio-based polyethylene composite material according to claim 2, characterized in that The alkyl chain length of the alkyl acid chloride is C10-C18.

4. The bio-based polyethylene composite material according to claim 2, characterized in that The usage ratio of the alkylated monomer, diene, ethanedithiol, photoinitiator TPO, tert-butyl perbenzoate and dimethylacetamide is 10mmol: 60-80mmol: 0.1-0.12mol: 8-12mg: 5-10mg: 16-24mL.

5. The bio-based polyethylene composite material according to claim 4, characterized in that The diene is one or more of 1,5-hexadiene, 1,7-octadiene and 1,9-decadiene.

6. The bio-based polyethylene composite material according to claim 1, characterized in that The inorganic metal flame retardant is a compound of magnesium hydroxide and aluminum hydroxide.

7. The bio-based polyethylene composite material according to claim 1, characterized in that The lubricant is oxidized polyethylene wax.

8. The method for preparing a composite material based on bio-based polyethylene according to any one of claims 1 to 7, characterized in that: The specific method is: the raw materials are mixed by a high-speed mixer, transferred to a twin-screw extruder, the temperature zones are controlled to be set as: zone one 170-180°C, zone two 180-190°C, zone three 190-195°C, the die head temperature is 200°C, the mixture is plasticized, extruded and pelletized to obtain a composite material.

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