Preparation And Properties Of Poly(Lactic Acid)/Lignin-Modified Polyvinyl Acetate Composites

Poly(lactic acid)(PLA) has good application in the field of packaging because of its good biodegradability, tensile strength, and film-forming properties. However, the disadvantages of high brittleness and high cost limit the wider application of PLA. PLA/lignin-modified polyvinyl acetate (L-PVAc) composites with excellent toughness were prepared by melt blending PLA with modifier L-PVAc. The mechanical properties, thermal properties and morphology of the composites were characterized to evaluate the effect of L-PVAc content on the properties of the composites. The results showed that the introduction of L-PVAc could increase the impact strength, elongation at break, glass transition temperature, melting temperature and the degree of crystallinity of PLA/L-PVAc composites. When the L-PVAc content reached up to 20.0 wt%, the impact strength, elongation at break, glass transition temperature, melting temperature and the degree of crystallinity of the composites were increased by 298.2%, 167.5%, 3.8%, 1.8%, and 78.8%, respectively compared to pure PLA due to the good toughness of PVAc and heterogeneous nucleation of lignin. This research can promote the high-value utilization of lignin and the application of PLA in the fields of clothing, agriculture, medical and hygiene.