CN-121991475-A - Polylactic acid composite material and preparation method and application thereof

Abstract

The invention relates to the field of high polymer materials, and discloses a polylactic acid composite material, a preparation method and application thereof, wherein the polylactic acid composite material comprises polylactic acid, polyamide and basalt fiber, and the content of the polylactic acid is 50-65 parts by mass and the content of the basalt fiber is 5-20 parts by mass relative to 30 parts by mass of polyamide. The polylactic acid composite material has good mechanical property and heat resistance, the tensile strength is more than or equal to 45MPa, the elongation at break is 277-401%, the impact strength is more than or equal to 84kJ/m 2 , and the heat-resistant temperature is more than or equal to 65 ℃.

Inventors

• LIU ZHIGANG
• PAN HONGWEI
• BIAN JUNJIA
• ZHANG HUILIANG
• SUI MIAO
• ZHAO YAN
• XIAO YANG
• YANG HUILI

Assignees

• 吉林中粮生化有限公司
• 中国科学院长春应用化学研究所

Dates

Publication Date

20260508

Application Date

20241104

Claims (10)

1. 1. The polylactic acid composite material is characterized by comprising polylactic acid, polyamide and basalt fiber; Wherein the content of polylactic acid is 50-65 parts by mass and the content of basalt fiber is 5-20 parts by mass relative to 30 parts by mass of polyamide.
2. 2. The composite material according to claim 1, wherein the content of polylactic acid in the composite material is 55 to 65 parts by mass, the content of polyamide is 30 parts by mass, and the content of basalt fiber is 10 to 20 parts by mass.
3. 3. The composite material according to claim 1 or 2, wherein the polyamide is obtained by polycondensation of hexamethylene diisocyanate and hydrogenated dimer acid.
4. 4. A composite material according to claim 3, wherein the molar ratio of isocyanate groups in the hexamethylene diisocyanate to carboxyl groups in the hydrogenated dimer acid is 1-2:1; and/or the temperature of the polycondensation is 150-200 ℃ and the time is 10min; Preferably, the polycondensation is carried out under stirring conditions, the stirring being at a rate of 50-200r/min.
5. 5. The composite material according to any one of claims 1 to 4, wherein the polylactic acid has a number average molecular weight of 150,000 to 200,000g/mol.
6. 6. The composite material according to any one of claims 1 to 5, wherein the basalt fiber has a monofilament fiber fineness of 100dtex or less; preferably, the basalt fiber is a silane coupling agent modified basalt fiber.
7. 7. A method for preparing polylactic acid composite material is characterized by comprising the steps of mixing hydrogenated dimer acid and hexamethylene diisocyanate to react in the presence of molten polylactic acid and optional basalt fiber.
8. 8. The method according to claim 7, wherein the reaction is carried out at a temperature of 150-200 ℃ for 10min and at a stirring rate of 50-200r/min.
9. 9. A polylactic acid composite material prepared according to the method of claim 7 or 8.
10. 10. Use of the polylactic acid composite material according to any one of claims 1-6 and 9 in disposable environmental-friendly high-temperature-resistant materials.

Description

Polylactic acid composite material and preparation method and application thereof Technical Field The invention relates to the field of high polymer materials, in particular to a polylactic acid composite material and a preparation method and application thereof. Background Thermoplastic polymers, such as polyolefins and polyesters, can be effectively compounded with natural fibers (primarily lignocellulose and its derivatives), both reducing production costs and improving material properties. However, existing polylactic acid (PLA) composites still face some significant challenges and drawbacks in practical applications. First, the brittleness of the polylactic acid matrix is the greatest limiting factor in engineering applications. Although polylactic acid has good biodegradability and environmental protection characteristics, it has poor toughness and strength, and particularly, is easily broken at low temperature, thus limiting its application in fields where high mechanical properties are required. Second, the incompatibility of natural fibers with polylactic acid matrix, especially vegetable fibers (such as jute, hemp, flax, wood fibers, etc.), results in poor interfacial adhesion of the composite. This interfacial incompatibility directly affects the dispersibility of the fibers, causing the fibers to form aggregates in the matrix, thereby reducing the mechanical properties of the composite. In addition, the high hygroscopicity of plant fibers also leads to reduced performance of the composite material in a humid environment, further limiting its application. Disclosure of Invention In order to solve the problem of poor mechanical property and heat resistance of the polylactic acid composite material in the prior art, the polylactic acid composite material, the preparation method and the application thereof are provided, and the mechanical property of the polylactic acid composite material is higher in mechanical property and better in heat resistance. In order to achieve the above object, a first aspect of the present invention provides a polylactic acid composite material comprising polylactic acid, polyamide and optionally basalt fiber; Wherein the content of polylactic acid is 50-65 parts by mass and the content of basalt fiber is 5-20 parts by mass relative to 30 parts by mass of polyamide. In a second aspect, the present invention provides a method for preparing a polylactic acid composite material, comprising mixing hydrogenated dimer acid and hexamethylene diisocyanate in the presence of molten polylactic acid and optional basalt fiber for reaction. The third aspect of the invention provides a polylactic acid composite material prepared by the method provided by the second aspect of the invention. The fourth aspect of the invention provides an application of the polylactic acid composite material provided by the first aspect and the third aspect of the invention in a disposable environment-friendly high-temperature-resistant material. The polylactic acid composite material provided by the invention has good mechanical property and heat resistance, the tensile strength is more than or equal to 45MPa, the elongation at break is 277-401%, the impact strength is more than or equal to 84kJ/m 2, and the heat-resistant temperature is more than or equal to 65 ℃. Detailed Description The endpoints and any values of the ranges disclosed herein are not limited to the precise range or value, and are understood to encompass values approaching those ranges or values. For numerical ranges, one or more new numerical ranges may be found between the endpoints of each range, between the endpoint of each range and the individual point value, and between the individual point value, in combination with each other, and are to be considered as specifically disclosed herein. The first aspect of the present invention provides a polylactic acid composite material comprising polylactic acid (PLA), polyamide and Basalt Fiber (BF); Wherein the content of polylactic acid is 50-65 parts by mass and the content of basalt fiber is 5-20 parts by mass relative to 30 parts by mass of polyamide. The basalt fiber and polymer in the polylactic acid composite material provided by the invention have strong interfacial bonding force, the composite material has good mechanical property and heat resistance, the tensile strength is more than or equal to 45MPa, the elongation at break is 277-401%, the impact strength is more than or equal to 84kJ/m 2, and the heat-resistant temperature is more than or equal to 65 ℃. According to a preferred embodiment of the present invention, the content of polylactic acid in the composite material is 50 to 65 parts by mass, the content of polyamide is 30 parts by mass, and the content of basalt fiber is 5 to 20 parts by mass. In the present invention, when the composition of the polylactic acid composite material is within the above-mentioned range, the mechanical properties and heat resistance of the p