Lignin-containing biodegradable polyester compound bead foaming material with high crystallization rate and preparation method thereof

Abstract

The invention discloses a lignin-containing biodegradable polyester compound bead foaming material with a high crystallization rate and a preparation method thereof, the preparation method comprises the following steps: (1) melting and blending poly (butylene adipate terephthalate), an anhydride compound and a peroxide cross-linking agent to obtain MAH-g-PBAT particles; (2) carrying out blending granulation on the particles, degradable resin, lignin and a chain extender to obtain biodegradable polyester compound beads; and (3) putting the biodegradable polyester composite beads into a high-pressure mold, and carrying out mold pressing foaming by taking foaming gas as a foaming agent, thereby obtaining the biodegradable polyester composite beads. The MAH-g-PBAT and the chain extender can synergistically improve the compatibility of PBAT, PLA and lignin, promote chain branching and chain intertwining, successfully combine two melting points into one melting point, broaden the foaming interval, improve the foaming performance and facilitate steam forming of beads.

Description

technical field [0001] The invention relates to the field of biodegradable polymer materials, in particular to a biodegradable polyester composite bead foam material containing lignin with high crystallization rate and a preparation method thereof. Background technique [0002] Biodegradable foaming materials such as polybutylene adipate terephthalate (PBAT), polylactic acid (PLA) and various composite materials have good thermal stability and mechanical properties, and are the solution to the problem of "plastic" The important way of "white pollution", especially in the field of foam materials such as packaging, cushioning, heat insulation and sound insulation, has attracted more and more attention; however, at present, biodegradable plastics such as PBAT and PLA are not available compared with traditional PS, PP, etc. For degradable plastics, the market price is expensive, and large-scale application is hindered. [0003] Both PBAT and PLA are crystalline polymers, which ...

AI Technical Summary

Problems solved by technology

In the bead steam forming process, if the crystallization rate is low, it is not conducive to the diffusion and recrystallization of the bead interface domain chain, which affects the formability of the product

At present, the nucleating agents for biodegradation on the market can be divided into three categories: inorganic material nucleating agents, organic compound nucleating agents, salts and polymer material nucleating agents, but these nucleating agents have poor compatibility , It is easy to cause the performance degradation or instability of plastic products, which limits its application range, and these nucleating agents will have an adverse impact on the environment, and some nano-scale nucleating agents are expensive; the nucleating agents are highly efficient, green, Harmless, the development of bio-based non-toxic nucleating agents is also one of the main directions for future development

[0004] The melting point difference between PBAT and PLA composite materials is large, which will lead to no suitable foaming temperature range. The poor compatibility of PBAT / PLA will cause the foaming gas to escape during the foaming process, resulting in low foaming ratio and foaming. Inhomogeneous pore size, merging and collapse of cells, at present, the compatibility can be effectively improved by chain extenders, but the compatibility between the two still needs to be further improved

For example, the patent CN111320845A provides a graphene-enhanced and toughened PBAT / PLA composite material foaming method, using graphene as its nucleating agent, these nucleating agents improve the foaming performance of biodegradable polyester, and increase the disadvantage of cost Influence; moreover, it adopts the method of autoclave pressure foaming, which makes PLA, PBAT and other polyester biodegradable materials prone to hydrolysis and depolymerization under the condition of high temperature water heat, which will adversely affect the performance of the final product

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