Modified Biomass-Reinforced Polylactic Acid Composites

Abstract

Polylactic acid (PLA), as a renewable and biodegradable green polymer material, is hailed as one of the most promising biopolymers capable of replacing petroleum-derived polymers for industrial applications. Nevertheless, its limited toughness, thermal stability, and barrier properties have restricted its extensive application. To address these drawbacks in PLA, research efforts have primarily focused on enhancing its properties through copolymerization, blending, and plasticization. Notably, the blending of modified biomass with PLA is expected not only to effectively improve its deficiencies but also to maintain its biodegradability, creating a fully green composite with substantial developmental prospects. This review provides a comprehensive overview of modified biomass-reinforced PLA, with an emphasis on the improvements in PLA's mechanical properties, thermal stability, and barrier properties achieved through modified cellulose, lignin, and starch. At the end of the article, a brief exploration of plasma modification of biomass is presented and provides a promising outlook for the application of reinforced PLA composite materials in the future. This review provides valuable insights regarding the path towards enhancing PLA.

Keywords: composite material; modified biomass; polylactic acid (PLA).

Figure 1

Stereoisomers of lactic acid, lactide, and PLA.

Figure 2

Different synthesis processes of PLA.

Figure 3

The chemical structure of cellulose.

Figure 4

Three structural units of lignin.

Figure 5

The main connections between lignin units.

Figure 6

The process of lignin acetylation.

Figure 7

The structures of amylose and amylopectin.

Figure 8

Schematic diagram of the plasma modification treatment equipment.