Degradation behaviors and crystallization of rapidly degradable polylactic acid prepared by melting through coordination complexation reaction

Abstract

The nondegradability of petroleum-based non-degradable plastics leads to accumulation of a large amount of waste. The waste disposal method seriously pollutes the environment. The development and application of biodegradable polymers are considered as a green solution to the problem of environmental pollution. However, as the market for degradable materials continues to expand, the rate of production largely exceeds the rate of natural degradation, and the waste accumulation problem cannot be effectively addressed. In this study, PLA-modified materials were prepared by a melt blending method with polylactic acid (PLA) as a matrix material and stannous octoate (Sn(Oct)2) as an accelerator to increase the degradation rate of PLA. The Sn atom in Sn(Oct)2 complexed with the ester group of the PLA molecular chain, leading to destruction of the PLA molecular chain. When the content of the accelerator reached 2 phr, the degradation rate of the modified samples in an alkali solution was more than two times higher than that of the pure PLA, and the biodegradation rate was increased by 73.97% compared to the pure PLA. In addition, the crystallization behavior of PLA can be regulated by Sn(Oct)2. The mechanisms of the acceleration of the degradation and effect on the crystallization behavior were investigated.