Biodegradable polylactic acid based composite and application thereof

Abstract

The invention discloses a biodegradable polylactic acid based composite and application thereof. 65-80 wt% of polylactic acid with the weight-average molecular weight of 10-180,000 and the molecular weight distribution index of 1.2-2.0, 7-9 wt% of aliphatic polyesters, 3-8 wt% of one or two plasticizers, and one or two inorganic fillers are subjected to vacuum drying; then mixing and granulating are conducted to obtain the biodegradable polylactic acid based composite; the inorganic fillers are subjected to surface treatment by one or more coupling agents, and are selected from one or two of calcium carbonate, talcum powder and wollastonite; the average particle size of the inorganic fillers is 2-20 microns; before the surface treatment, the weight ratio of the inorganic fillers to the coupling agents is 100:(1.5-5). As for the application of the biodegradable polylactic acid based composite, the biodegradable polylactic acid based composite is used as a raw material to be used for preparing disposable tableware, packing materials or films. The mechanical property of the biodegradable polylactic acid based composite are improved greatly compared with that of polylactic acid. At the same time, the amount of the added polyester modifiers is small, and the amount of the added inorganic fillers is large, so that the cost is greatly reduced.

Description

technical field [0001] The invention relates to a biodegradable polylactic acid-based composite material with high toughness and high heat resistance, in particular to a high-performance, low-cost biodegradable polylactic acid-based composite material that can be used as a general-purpose resin for injection molding, blister molding, and blow molding processes. materials, their preparation methods and applications. Background technique [0002] In recent years, based on the consideration of non-renewable energy sources such as petroleum and environmental protection, countries around the world have extensively carried out research and development of non-petroleum-based biodegradable materials, and polylactic acid is considered to be one of the most promising alternatives to traditional plastics. The raw material of polylactic acid is fermented from corn, and it can produce fully degradable plastics, which can be decomposed into carbon dioxide and water after the action of mic...

AI Technical Summary

Problems solved by technology

[0003] Blister molded products have high requirements on material thermal properties, mold release, impact resistance, toughness, etc., but polylactic acid itself is hard and brittle, and the products after blistering cannot meet the requirements, so modification research is needed

Disclosed in CN100577731C is a kind of preparation method of polydibasic acid glycol ester / polylactic acid alloy, makes it suitable for molding processes such as blow molding, injection molding or blister, but additive price and content are higher, increased polylactic acid product the cost of

The biodegradable injection molded body invented by CN100432146C uses polylactic acid resin as the base material, and adds surface treatment inorganic fillers for modification, so that the prepared molded body has good mechanical properties and flame retardancy, but the formula resin cannot be used In blister molding process

The biodegradable composite and modified special resins disclosed in CN100537661C and CN1858114A can be processed by various molding processes such as injection molding, blow molding, and blister molding, and a certain amount of inorganic filler and starch are added, which can greatly reduce the cost of biodegradable products. Most starch-based biodegradable materials and products have disadvantages such as strong water absorption, easy deformation, and poor weather resistance. The content of other aliphatic polyesters (such as polybutylene succinate) added in these two inventions is relatively high. Especially when as plastic-absorbing grade resin, the biodegradable composite disclosed in CN100537661C and CN1858114A and the content of polybutylene succinate in the modified resin are as high as 55%-73.5%, so that the cost of biodegradable plastic-absorbing products is relatively low. High, it is impossible to process products such as low-cost disposable tableware and packaging materials through the blister molding process