Immobilization of Proteinase K into PLA for self-biodegradable

Biodegradable plastics offer a promising alternative to petroleum-based plastics for alleviating environmental pressure. Biodegradable plastics have a long degradation cycle time and require strict degradation conditions. Enzymatic degradation represents a highly effective approach for enhancing the degradation efficiency of biodegradable plastics. However, enzymes typically do not perform well at the high temperatures used in polymer processing. Therefore, we propose a strategy that accelerates polylactic acid (PLA) degradation by embedding it with an immobilized Proteinase K (Pro K). Pro K was stably immobilized within Santa Barbara Amorphous-15 (SBA-15) pores using genipin as an efficient crosslinker. Meanwhile, molecular docking technology was used to analyze the crosslinking mechanism. The immobilized Pro K can retain 47 % of its initial activity after hot-pressing at 175 °C for 10 min. The immobilized Pro K was uniformly dispersed in PLA to prepare Pro K@SBA-15-PLA film through melt extrusion. The Pro K@SBA-15-PLAfilm exhibited stable degradation performance in aqueous environments, and the complete degradation time was 0.64 times of PLA film under composting conditions. This study introduces a comprehensive approach to expedite the degradation of plastics and is tailored for industrial-scale applications.