Biodegradable polyethylene composite material and preparation method thereof

Abstract

The invention is suitable for the technical field of polyethylene, and provides a biodegradable polyethylene composite material and a preparation method thereof. The polyethylene composite material is prepared from the following components in parts by mass: 50 to 90 parts of polyethylene, 5 to 15 parts of polylactic acid, 10 to 30 parts of starch, 3 to 9 parts of talcum powder, 2 to 6 parts of bamboo fiber, 2 to 6 parts of epoxidized soybean oil, 1 to 3 parts of tetracarboxyl metalloporphyrin, 0.5 to 2 parts of plasticizer, 0.7 to 1.5 parts of compatilizer and 4 to 10 parts of glass fiber. Preferably, the polyethylene is low-density polyethylene; preferably, the weight ratio of the polylactic acid to the starch is 1: 2; preferably, the tetra-carboxyl metalloporphyrin is one or more of tetra-carboxyl iron porphyrin, tetra-carboxyl cobalt porphyrin and tetra-carboxyl copper porphyrin. The polyethylene composite material prepared by the invention has excellent processability and flexibility while keeping high strength and toughness, and the degradation efficiency of the polyethylene composite material is greatly improved by combining biodegradation and photodegradation.

Description

Technical Field

[0001] The present invention relates to the technical field of polyethylene, and specifically to a biodegradable polyethylene composite material and a preparation method thereof. Background Art

[0002] Polyethylene (PE for short) is a common synthetic polymer material and one of the most widely used plastics. It is polymerized from ethylene monomers, has a simple molecular structure, and has good chemical resistance, low-temperature toughness, and electrical insulation properties. According to different polymerization processes and molecular weights, polyethylene can be divided into different types, such as low-density polyethylene (LDPE), high-density polyethylene (HDPE), and linear low-density polyethylene (LLDPE). With its excellent properties and wide application fields, polyethylene has become an indispensable important material in modern society. For example:

[0003] Chinese Patent with application number CN202110846786.9 and publication number CN115677894B provides a preparation method of polyethylene, polyethylene, and a polyethylene composition. The polyethylene preparation method of the present invention includes the following steps: adding ethylene, hydrogen, and a catalyst into a first reactor, and obtaining a first powder after polymerization; feeding the first powder into a second reactor, adding hexene, ethylene, and hydrogen into the second reactor, and obtaining the polyethylene after polymerization; wherein, the melt mass flow rate of the polyethylene is (0.30 - 0.80) g / 10min. The polyethylene preparation method of this invention can efficiently produce polyethylene, and the obtained polyethylene has good high-temperature long-term creep resistance. The polyethylene composition of the present invention includes the above polyethylene, antioxidant, antacid, and processing aid. The polyethylene composition not only has excellent high-temperature long-term creep resistance, but also has strong processability, a large application range, and broad market prospects.

[0004] Chinese Patent with application number CN202010429821.2 and publication number CN111607145B provides a polyethylene material and a polyethylene pipe. The provided polyethylene material contains cellulose modified by hyperbranched polyester, and the hyperbranched polyester is a hyperbranched polyester containing cage-type polyhedral oligomeric silsesquioxane. In addition, it also contains carbon black masterbatch, coupling agent, and high-density polyethylene. The polyethylene pipe prepared from this polyethylene material has the advantages of uniform carbon black dispersion, thicker wall thickness, larger pipe diameter, stable quality, and long service life.

[0005] In summary, although polyethylene has many advantages, traditional polyethylene materials are difficult to degrade in the natural environment and will cause serious environmental pollution. Therefore, the present invention provides a biodegradable polyethylene composite material and a preparation method thereof to reduce environmental pollution caused by polyethylene materials. Summary of the Invention

[0006] The object of the present invention is to provide a biodegradable polyethylene composite material and a preparation method thereof, so as to solve the problem that traditional polyethylene materials in the prior art are difficult to degrade in the natural environment and will cause serious pollution to the environment.

[0007] To achieve the above object, the present invention provides the following technical solutions: In the first aspect of the present invention, a biodegradable polyethylene composite material is provided, and the polyethylene composite material includes the following components and mass fractions:

[0008] 50 - 90 parts of polyethylene, 5 - 15 parts of polylactic acid, 10 - 30 parts of starch, 3 - 9 parts of talcum powder, 2 - 6 parts of bamboo fiber, 2 - 6 parts of epoxidized soybean oil, 1 - 3 parts of tetracarboxylic metal porphyrin, 0.5 - 2 parts of plasticizer, 0.7 - 1.5 parts of compatibilizer, and 4 - 10 parts of glass fiber.

[0009] Preferably, the polyethylene is low - density polyethylene.

[0010] Preferably, the weight ratio of polylactic acid to starch is 1:2.

[0011] Preferably, the tetracarboxylic metal porphyrin is one or more of tetracarboxylic iron porphyrin, tetracarboxylic cobalt porphyrin, and tetracarboxylic copper porphyrin.

[0012] Preferably, the plasticizer is one or more of dioctyl phthalate, bis(2 - ethylhexyl) phthalate, and bis(2 - ethylhexyl) diphenyl phosphate.

[0013] Preferably, the compatibilizer is one or more of PE - g - MAH, PP - g - MAH, and SEBS.

[0014] Preferably, the polyethylene composite material further includes soy protein, wheat protein, and fructose.

[0015] Preferably, the mass fractions of soy protein, wheat protein, and fructose are 2 - 6 parts of soy protein, 1 - 3 parts of wheat protein, and 0.5 - 1.5 parts of fructose.

[0016] In the second aspect of the present invention, a preparation method of the polyethylene composite material described in the first aspect of the present invention is provided, including the following steps:

[0017] Mix the components in proportion in sequence, then add them to an extruder, and carry out extrusion molding at a temperature of 160 - 220 °C to obtain the polyethylene composite material.

[0018] The present invention has at least the following beneficial effects:

[0019] A biodegradable polyethylene composite material provided by the present invention and its preparation method. The obtained polyethylene composite material not only maintains high strength and toughness, but also has excellent processing performance and flexibility. By combining biodegradation and photodegradation methods, the degradation efficiency of the polyethylene composite material is greatly improved. Detailed implementation manners

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0021] Example 1

[0022] This example provides a biodegradable polyethylene composite material, including the following components and mass fractions:

[0023] 50 parts of polyethylene, 5 parts of polylactic acid, 10 parts of starch, 3 parts of talcum powder, 2 parts of bamboo fiber, 2 parts of epoxidized soybean oil, 1 part of tetracarboxylic metal porphyrin, 0.5 part of plasticizer, 0.7 part of compatibilizer, 4 parts of glass fiber.

[0024] Among them, the polyethylene is low-density polyethylene; the weight ratio of polylactic acid to starch is 1:2.

[0025] Among them, the tetracarboxylic metal porphyrin is tetracarboxylic iron porphyrin; the plasticizer is dioctyl phthalate; the compatibilizer is PE-g-MAH.

[0026] The above polyethylene composite material includes the following steps:

[0027] Mix the components in proportion in sequence, and then add them to an extruder, and carry out extrusion molding at a temperature of 160 °C to obtain a polyethylene composite material.

[0028] Example 2

[0029] This example provides a biodegradable polyethylene composite material, including the following components and mass fractions:

[0030] 75 parts of polyethylene, 10 parts of polylactic acid, 20 parts of starch, 6 parts of talcum powder, 3 parts of bamboo fiber, 5 parts of epoxidized soybean oil, 2 parts of tetracarboxylic metal porphyrin, 1.3 parts of plasticizer, 1 part of compatibilizer, 7 parts of glass fiber.

[0031] Among them, the polyethylene is low-density polyethylene; the weight ratio of polylactic acid to starch is 1:2.

[0032] Among them, the metal tetracarboxyl porphyrin is cobalt tetracarboxyl porphyrin; the plasticizer is bis(2-ethylhexyl) phthalate; the compatibilizer is PP-g-MAH.

[0033] The above polyethylene composite material comprises the following steps:

[0034] Mix the components in proportion successively, then add them into an extruder, and carry out extrusion molding at a temperature of 200 °C to obtain the polyethylene composite material.

[0035] Example 3

[0036] This example provides a biodegradable polyethylene composite material, which comprises the following components and mass parts:

[0037] 90 parts of polyethylene, 15 parts of polylactic acid, 30 parts of starch, 9 parts of talcum powder, 6 parts of bamboo fiber, 6 parts of epoxidized soybean oil, 3 parts of metal tetracarboxyl porphyrin, 2 parts of plasticizer, 1.5 parts of compatibilizer, 10 parts of glass fiber.

[0038] Among them, the polyethylene is low-density polyethylene; the weight ratio of polylactic acid to starch is 1:2.

[0039] Among them, the metal tetracarboxyl porphyrin is copper tetracarboxyl porphyrin; the plasticizer is bis(2-ethylhexyl) diphenyl phosphate; the compatibilizer is SEBS.

[0040] The above polyethylene composite material comprises the following steps:

[0041] Mix the components in proportion successively, then add them into an extruder, and carry out extrusion molding at a temperature of 220 °C to obtain the polyethylene composite material.

[0042] Example 4

[0043] This example provides a biodegradable polyethylene composite material, which comprises the following components and mass parts:

[0044] 50 parts of polyethylene, 5 parts of polylactic acid, 10 parts of starch, 3 parts of talcum powder, 2 parts of bamboo fiber, 2 parts of epoxidized soybean oil, 1 part of metal tetracarboxyl porphyrin, 0.5 part of plasticizer, 0.7 part of compatibilizer, 4 parts of glass fiber, 2 parts of soy protein, 1 part of wheat protein, and 0.5 part of fructose.

[0045] The rest is the same as Example 1.

[0046] Example 5

[0047] This example provides a biodegradable polyethylene composite material, which comprises the following components and mass parts:

[0048] 75 parts of polyethylene, 10 parts of polylactic acid, 20 parts of starch, 6 parts of talcum powder, 3 parts of bamboo fiber, 5 parts of epoxidized soybean oil, 2 parts of tetracarboxylic metal porphyrin, 1.3 parts of plasticizer, 1 part of compatibilizer, 7 parts of glass fiber, 4 parts of soy protein, 2 parts of wheat protein, and 1 part of fructose.

[0049] The rest is the same as in Example 2.

[0050] Example 6

[0051] This example provides a biodegradable polyethylene composite material, including the following components and mass fractions:

[0052] 90 parts of polyethylene, 15 parts of polylactic acid, 30 parts of starch, 9 parts of talcum powder, 6 parts of bamboo fiber, 6 parts of epoxidized soybean oil, 3 parts of tetracarboxylic metal porphyrin, 2 parts of plasticizer, 1.5 parts of compatibilizer, 10 parts of glass fiber, 6 parts of soy protein, 3 parts of wheat protein, and 1.5 parts of fructose.

[0053] The rest is the same as in Example 3.

[0054] In the present invention, the addition of polylactic acid and starch significantly improves the biodegradability of the material and reduces environmental pollution; talcum powder, bamboo fiber, and glass fiber enhance the strength and toughness of the material, making it more durable during application; epoxidized soybean oil as a plasticizer can improve the processing performance and flexibility of the material; the plasticizer and compatibilizer improve the processing performance of the material and the compatibility between components, making the composite material more uniform and stable; soy protein, wheat protein, and fructose further improve the biodegradability of the material.

[0055] In addition, tetracarboxylic metal porphyrin in the present invention is an effective photocatalyst, which can promote the photocatalysis of the polyethylene composite material under light conditions. Thus, the present invention combines biodegradation and photocatalysis, greatly improving the degradation efficiency of the polyethylene composite material and reducing environmental pollution.

[0056] A series of relevant performance tests were carried out on the products prepared in the above Examples 1-6, and the results are shown in the following table:

[0057] Test Items Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Tensile Strength 30.2 MPa 30.7 MPa 31.4 MPa 30.6 MPa 30.9 MPa 31.7 MPa Elongation at Break of Tensile 116％ 121％ 126％ 119％ 125％ 131％ Flexural Strength 51.7 MPa 54.5 MPa 57.6 MPa 53.2 MPa 57.2 MPa 59.3 MPa Heat Deflection Temperature 75℃ 75℃ 75℃ 75℃ 75℃ 75℃ Degradation Rate 82％ 84％ 85％ 83％ 86％ 88％

[0058] In summary, the biodegradable polyethylene composite material of the present invention not only has good physical properties but also has significant biodegradability, with a degradation rate as high as 82% to 88%. This shows that the polyethylene composite material of the present invention can be effectively decomposed in the natural environment, significantly reducing environmental pollution.

[0059] In addition, by adding biodegradable components such as polylactic acid and starch, as well as reinforcing materials such as talcum powder, bamboo fiber, and glass fiber, the polyethylene composite material of the present invention not only maintains high strength and toughness but also has excellent processing performance and flexibility.

[0060] By combining biodegradation and photodegradation, the present invention not only improves the degradation efficiency of the polyethylene composite material but also broadens its application scope, enabling it to exhibit good degradation performance under various environmental conditions.

[0061] In summary, the biodegradable polyethylene composite material of the present invention and its preparation method provide an effective solution to the problem that traditional polyethylene materials are difficult to degrade and cause serious environmental pollution. This composite material not only has excellent physical and processing properties but also has good biodegradability and photodegradability, and is expected to be widely used in various fields, making an important contribution to the development of the environmental protection industry.

[0062] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced by the present invention.

[0063] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A biodegradable polyethylene composite material, characterized in that, The polyethylene composite material comprises the following components and parts by mass: 50 - 90 parts of polyethylene, 5 - 15 parts of polylactic acid, 10 - 30 parts of starch, 3 - 9 parts of talcum powder, 2 - 6 parts of bamboo fiber, 2 - 6 parts of epoxidized soybean oil, 1 - 3 parts of tetracarboxylic metal porphyrin, 0.5 - 2 parts of plasticizer, 0.7 - 1.5 parts of compatibilizer, and 4 - 10 parts of glass fiber.

2. The biodegradable polyethylene composite material according to claim 1, characterized in that: The polyethylene is low - density polyethylene.

3. A biodegradable polyethylene composite according to claim 1, characterized in that: The weight ratio of the polylactic acid to the starch is 1:

2.

4. A biodegradable polyethylene composite according to claim 1, characterized in that: The tetracarboxylic metal porphyrin is one or more of tetracarboxylic iron porphyrin, tetracarboxylic cobalt porphyrin, and tetracarboxylic copper porphyrin.

5. A biodegradable polyethylene composite according to claim 1, characterized in that: The plasticizer is one or more of dioctyl phthalate, bis(2 - ethylhexyl) phthalate, and bis(2 - ethylhexyl) diphenyl phosphate.

6. A biodegradable polyethylene composite according to claim 1, characterized in that: The compatibilizer is one or more of PE - g - MAH, PP - g - MAH, and SEBS.

7. A biodegradable polyethylene composite according to claim 1, characterized in that: The polyethylene composite material further comprises soy protein, wheat protein, and fructose.

8. A biodegradable polyethylene composite according to claim 7, characterized in that: The parts by mass of the soy protein, wheat protein, and fructose are 2 - 6 parts of soy protein, 1 - 3 parts of wheat protein, and 0.5 - 1.5 parts of fructose.

9. A method for preparing the polyethylene composite material according to any one of claims 1 to 8, characterized in that, It includes the following steps: Mix the components in sequence according to the proportion, then add them into an extruder, and carry out extrusion molding at a temperature of 160 - 220 °C to obtain the polyethylene composite material.