Effect of Antihydrolysis Agents on the Structure and Properties of PBAT/PGA Blend Films under Artificial Accelerated Weathering

The PBAT/PGA blend film, composed of poly­(butylene adipate-co-terephthalate) and poly­(glycolic acid), is currently considered promising, cost-effective, and comprehensively performing biodegradable mulch film. However, the relatively fast hydrolysis rate limits its service time during application. This work endeavored to postpone the hydrolysis rate of the PBAT/PGA blend films by using polycarbodiimide (PCDI) as an antihydrolysis agent. Through artificial accelerated weathering experiments, thorough analysis of the microstructure, surface morphology, thermal properties, and mechanical properties, of the blend films was conducted. Moreover, the antihydrolysis mechanism was clearly revealed. Results showed that the introduction of PCDI enhanced the durability and overall performance of PBAT/PGA blend films. PCDI not only consumed the carboxyl-end groups of polymer molecular chains but also acted as a chain extender. In summary, the enhanced hydrolysis stability and excellent mechanical properties endow the PBAT/PGA blend films with significant developmental potential for mulch films with a stable service life and superior performance.