Although PLA has good biodegradability, it also has some inherent defects in practical applications, such as easy to catalyze and poor impact resistance. Therefore, the addition of toughening agents can effectively improve the defects of PLA. Commonly used environment-friendly plasticizers include degradable polyesters, bio-based elastomers, natural polymers and their derivatives, and nanomaterials.

Among them, polybutylene terephthalate-adipate (PBAT) is the most studied toughening modified material. PBAT is an environmentally friendly biodegradable plastic, which is obtained by condensation polymerization of three monomers, adipic acid, terephthalic acid and butanediol. It combines the excellent properties of aromatic polyesters and aliphatic polyesters, such as excellent mechanical properties, impact resistance, toughness and heat resistance.

PLA, PBAT and their blends can all be degraded under the condition of digested sludge, and the degradation rate of pure PLA is slightly higher than that of PBAT. In addition, after adding an appropriate amount of PBAT, the glass transition temperature of the composite material increased and the thermal stability of the blend improved.

Some scholars have found that the aggregation structure of PBAT and PLA confirms that the biodegradation and hydrolysis rate of the amorphous region is higher than that of the crystalline region, because the structure of the amorphous region is looser and more susceptible to microorganisms and enzymes. This phenomenon also causes the crystallinity of the composite to increase over time. In addition, the degradation of the composite material is reflected by the change of the carbon-oxygen ratio, and the increase of the carbon-oxygen ratio after degradation is related to the content of PLA in the composite material.

Henan Techuang Biotechnology Co., Ltd. is a modern green and environmental protection enterprise integrating R&D, production, sales and technical services, providing services for biodegradable plastic bags and products. For more information, please visit the official website of Baydeebio: www.baydeebio.com