The brittleness of poly(lactic acid) (PLA) can be effectively mitigated by melt-blending it with poly(ε-caprolactone) (PCL). However, this approach compromises the vital strength and modulus of PLA, while the thermo-resistance remains low. In this regards, biochar (BC) was introduced to reinforce PLA/PCL composites as a modifier to improve mechanical and thermal performances. Herein, the effects of various contents of BC and annealing treatments were investigated on the properties of PLA/PCL composites. Interestingly, BC not only improved the mechanical properties of the composites but also reduced the semi-crystallization time by more than 70 %. Furthermore, annealing treatment increased the tensile strength and tensile modulus of the PLA/PCL/BC composites by 10.1 % and 6.3 %. Notably, Vicat softening temperatures of the composites with PLA to PCL proportions of 70:30 and 60:40 were increased to above 100°C. More importantly, the addition of BC effectively formed physical interaction with PLA, resulting in improvement in mechanical properties. Annealing treatment perfected the PLA crystal into a much more stable α-crystal form, resulting in an increase in thermal properties. This work paves an effective way to prepare PLA based biodegradable composites with high strength and thermo-resistance.

通过与聚(ε-己内酯)(PCL)熔融共混，可以有效减轻聚乳酸(PLA)的脆性。然而，这种方法损害了 PLA 的重要强度和模量，同时耐热性仍然较低。在这方面，引入生物炭（BC）作为改性剂来增强PLA/PCL复合材料，以提高机械和热性能。本文研究了不同BC含量和退火处理对PLA/PCL复合材料性能的影响。有趣的是，BC不仅提高了复合材料的机械性能，而且还使半结晶时间缩短了70%以上。此外，退火处理使PLA/PCL/BC复合材料的拉伸强度和拉伸模量分别提高了10.1%和6.3%。值得注意的是，PLA 与 PCL 比例为 70:30 和 60:40 的复合材料的维卡软化温度增加至 100°C 以上。更重要的是，BC的添加有效地与PLA形成物理相互作用，从而提高了机械性能。退火处理使 PLA 晶体变得更加稳定的 α 晶体形式，从而提高了热性能。这项工作为制备具有高强度和耐热性的PLA基可生物降解复合材料铺平了有效的途径。