Effect of polycarbodiimide, epoxy chain extenders and tannic acid on the hydrolysis and UV resistance of polylactic acid

Abstract

Polylactic acid (PLA) possesses characteristics such as biodegradability, ease of processing, and environmental friendliness, making it an ideal alternative to petroleum-based polymers. However, PLA has drawbacks such as susceptibility to hydrolysis and sensitivity to ultraviolet (UV) light, limiting its application in certain areas. In this study, poly(carbazole diimide) (PCDI) and the epoxy chain extender Joncryl ADR4468 (CE) were employed as a synergistic anti-hydrolysis agent for PLA, and tannic acid (TA) was used as a UV-resistant agent. A melt-blending process was employed to prepare PLA composite materials with enhanced resistance to both hydrolysis and UV radiation. The results indicate that the addition of PCDI-TA-CE significantly improved the performance of PLA. After 8 h of hydrolysis at 80 °C, the tensile strength of PLA increased from 38.31 MPa for pure PLA to 77.69 MPa with the incorporation of PCDI-TA-CE. The elongation at break increased from 0.6% to 1.5%, and the Ultraviolet Protection Factor (UPF) value elevated from 3.19 for pure PLA to 503.46.This demonstrates that PCDI, CE, and TA can effectively enhance the anti-hydrolysis and UV resistance properties of PLA.