阅读说明：本技术 一种植物纤维增强塑化淀粉发泡复合材料及其制备方法 (Plant fiber reinforced plasticized starch foaming composite material and preparation method thereof ) 是由 曾广胜 江太君 尹琛 孟聪 陈一 胡灿 刘水长 于 2019-11-11 设计创作，主要内容包括：本发明公开了一种植物纤维增强塑化淀粉发泡复合材料,以植物纤维、塑化淀粉、PLA发泡微珠和助剂为原材料制备而成。本发明采用大长径比的植物纤维作为骨架增强塑化淀粉为主材,通过引入PLA发泡微珠制备高强度植物纤维增强塑化淀粉复合材料,制备的复合材料密度降低20%以上,拉伸强度无明显降低,抗弯强度高。(The invention discloses a plant fiber reinforced plasticized starch foaming composite material which is prepared by taking plant fiber, plasticized starch, PLA foaming microbeads and an auxiliary agent as raw materials. According to the invention, the plant fiber with large length-diameter ratio is used as the skeleton reinforced plasticized starch as the main material, and the PLA foamed microspheres are introduced to prepare the high-strength plant fiber reinforced plasticized starch composite material, so that the density of the prepared composite material is reduced by more than 20%, the tensile strength is not obviously reduced, and the bending strength is high.)

1. The plant fiber reinforced plasticized starch foaming composite material is characterized by comprising the following raw materials in percentage by mass: plant fiber: 10-40% of plasticized starch: 30-50% of PLA foamed microspheres: 10-40% of an auxiliary agent: 0.5 to 6 percent.

2. The plant fiber reinforced plasticized starch foamed composite material according to claim 1, wherein the plant fiber has a water content of less than 5% and an aspect ratio of 4 to 20.

3. The plant fiber reinforced plasticized starch foamed composite material according to claim 1, wherein the particle size of the PLA foamed beads is 0.2-0.5 mm.

4. A plant fiber reinforced plasticized starch foamed composite according to claim 1, wherein the plasticized starch comprises starch and plasticizer.

5. The plant fiber reinforced plasticized starch foamed composite according to claim 4, wherein the starch is at least one of corn starch or tapioca starch; the plasticizer is glycerol, urea and polyethylene glycol.

6. The plant fiber reinforced plasticized starch foamed composite according to claim 1, wherein the auxiliary agent comprises a lubricant and an antioxidant.

7. The plant fiber reinforced plasticized starch foamed composite according to claim 6, wherein the lubricant is at least one of erucamide and EBS.

8. The plant fiber reinforced plasticized starch foamed composite of claim 6, wherein the antioxidant is at least one of 1076 and 1010.

9. The preparation method of the plant fiber reinforced plasticized starch foaming composite material according to any one of claims 1 to 8, characterized by comprising the following steps:

s1, adding starch and a plasticizer into a high-speed mixer, uniformly mixing, and standing to obtain plasticized starch;

s2, continuously adding the plant fibers, the PLA foamed microspheres and the auxiliary agent into a high-speed mixer to be uniformly mixed;

and S3, adding the mixture obtained in the step S2 into a parallel double-screw extruder for extrusion granulation to obtain the plant fiber reinforced plasticized starch foaming composite material.

10. The method according to claim 9, wherein the processing temperature during the granulation in step S3 is not more than 150 ℃.

Technical Field

The invention relates to the technical field of foaming materials, in particular to a plant fiber reinforced plasticized starch foaming composite material and a preparation method thereof.

Background

Starch is a renewable recyclable green material from natural plants, can be used as grain for human use, and is widely applied to the fields of chemical industry and new materials for preparing various composite materials. Due to the excellent biodegradability, starch is generally used as filling to prepare thermoplastic high-biochar-content bio-based composite materials, is widely applied to disposable products, and is more and more valued by people in the large environment that petrochemical resources are increasingly in shortage and white pollution is increasingly serious at present.

Plant fiber is another biomass resource which widely exists in nature and is renewable, has larger length-diameter ratio and higher specific strength compared with starch, and is a very important raw material for preparing bio-based composite materials. The plant fiber with higher length-diameter ratio and specific strength can construct a three-dimensional structure in the composite material to form a supporting framework, and the supporting framework is connected with the continuous phase matrix to form a structural reinforcing material. The starch and the plant fiber are mixed, the composite material with three-dimensional order is prepared by means of the three-dimensional structure formed by the plant fiber and the continuous bonding phase formed by the plasticized starch, the high-strength full-degradable composite material can be realized, the traditional material structure of single orientation or disordered orientation realized by simple blending is changed, and the application range of the material is expanded. However, the composite material prepared by directly compounding the plant fiber and the starch has the problems of large density and limited application range, and if the fully-degradable composite material can be subjected to foaming treatment, the density application range and the customer acceptance of the product can be greatly expanded.

Disclosure of Invention

The invention aims to provide a plant fiber reinforced plasticized starch foaming composite material which has low density and high tensile strength aiming at the defects in the prior art.

The invention also aims to provide a preparation method of the plant fiber reinforced plasticized starch foaming composite material.

The purpose of the invention is realized by the following technical scheme:

a plant fiber reinforced plasticized starch foaming composite material comprises the following raw materials in percentage by mass: plant fiber: 10-40% of plasticized starch: 30-50% of PLA foamed microspheres: 10-40% of an auxiliary agent: 0.5 to 6 percent.

Further, the water content of the plant fibers is lower than 5%, and the length-diameter ratio is 4-20.

Further, the particle size of the PLA foaming micro-beads is 0.2-0.5 mm.

Further, the plasticized starch comprises starch and a plasticizer.

Further, the starch is at least one of corn starch or cassava starch; the plasticizer is glycerol, urea and polyethylene glycol.

Further, the auxiliary agent comprises a lubricant and an antioxidant.

Further, the lubricant is at least one of erucamide and EBS.

Further, the antioxidant is at least one of 1076 and 1010.

The preparation method of the plant fiber reinforced plasticized starch foaming composite material comprises the following steps:

s1, adding starch and a plasticizer into a high-speed mixer, uniformly mixing, and standing to obtain plasticized starch;

s2, continuously adding the plant fibers, the PLA foamed microspheres and the auxiliary agent into a high-speed mixer to be uniformly mixed;

and S3, adding the mixture obtained in the step S2 into a parallel double-screw extruder for extrusion granulation to obtain the plant fiber reinforced plasticized starch foaming composite material.

Further, the processing temperature during the granulation in step S3 does not exceed 150 ℃.

Compared with the prior art, the invention has the following beneficial effects;

according to the invention, the plant fiber with large length-diameter ratio is used as the skeleton reinforced plasticized starch as the main material, and the PLA foamed microspheres are introduced to prepare the high-strength plant fiber reinforced plasticized starch composite material, so that the density of the prepared composite material is reduced by more than 20%, the tensile strength is not obviously reduced, the bending strength is high, and the application range can be better expanded.

Detailed Description

In order to facilitate understanding of the present invention, the present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited to the following specific examples.

Unless otherwise defined, all terms of art used hereinafter have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention.

Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment and the like used in the present invention are commercially available or can be prepared by existing methods.