碱处理对剑麻纤维增强聚乳酸可降解复合材料性能的影响

Effects of Alkali Treatment on Properties of Sisal Fiber Reinforced Poly Lactic Acid Composites

以剑麻纤维(SF)和聚乳酸(PLA)为原料,通过注塑成型工艺制备了剑麻纤维增强聚乳酸可降解复合材料。研究了连续碱处理剑麻纤维(CASF)和未改性处理剑麻纤维(USF)在不同含量时对复合材料力学性能、吸水性及可降解性能的影响。结果表明:剑麻纤维的质量分数会显著影响复合材料的力学性能、吸水性和降解性能。相较于未改性处理剑麻纤维(USF),碱处理剑麻纤维(CASF)可以进一步提高复合材料的力学性能,降低复合材料的吸水率,延缓剑麻纤维增强可降解树脂基复合材料的降解速率,且酶降解法相较于土埋法降解能够显著加快复合材料的降解速率。当剑麻纤维含量为20%时,CASF/PLA复合材料的拉伸强度、弯曲强度和弯曲模量相较于纯PLA和USF/PLA分别提高了32.71%、10.08%;19.63%、12.11%;97.33%、12.40%;其冲击强度相较于纯PLA提高了71.19%。

The natural fiber reinforced biodegradable polymer composites were prepared with short sisal fiber （SF） as reinforcement in ploy lactic acid（PLA） matrix by injection molding. The composites were prepared with untreated and treated short sisal fibers at different weight proportions in PLA matrix and investigated for mechanical,water absorption and degradation properties. The results showed that the mass fraction of fiber would affect the mechanical, water absorption and degradation properties of CASF/PLA composites. The continuous alkali treatment could further improve the mechanical properties of composites compared to unmodified sisal fiber,reduce the rate of water absorption of composites,delay the biodegradation rate of sisal fiber reinforced biodegradable polymer composites. The enzymatic environment had increased the rate of degradation of composites. When the sisal fiber content was 20% ,the tensile strength, flexural strength and flexural modulus of CASF/PLA composites compared to pure PLA and USF/PLA composites improved the 32.71% , 10. 08% ;19.63% , 12. 11% ;97.33% and 12.40% ;respectively. The impact strength of composites with treated sisal composites at 20% fiber loading was 71.19% high compared to that of neat PLA.