聚磷酸铵对聚乳酸/麦秸秆复合材料阻燃和力学性能的影响

Effect of Ammonium Polyphosphate on Flame Retardancy and Mechanical Properties of Polylactic Acid/Wheat Straw Composites

用聚磷酸铵(APP)对聚乳酸(PLA)/秸秆粉复合材料进行阻燃处理,对复合材料的阻燃性能、力学性能和热降解行为进行了分析。结果表明,APP添加量达到20份时,极限氧指数提高了33%,成炭率提高了330%,而且达到UL 94 V-0级,表现出显著的阻燃作用;APP的加入降低了复合材料的冲击性能,但能改善其刚性,对弯曲强度和密度影响不大;此外APP的添加还改变了复合材料的热降解行为,使其分解温度提前,稳定了PLA基体;材料燃烧后膨胀成多孔炭层,起到了隔热和阻氧的作用。

Influence of ammonium polyphosphate （APP） on flame retardancy, mechanical properties, and thermal degradation of polylactic acid （PLA）/wheat straw composites was investigated. It showed that limited oxygen index of the composites improved by 33 %, and UL 94 flammability rating was V-0, and char yield was increased by 330 % when APP＇s loading reached 20%. Unnotched Izod impact strength was reduced and the stiffness was improved with the addition of APP, while flexural strength and density were not affected. TGA test indicated that the thermal degradation behavior was changed when adding APP, which made the decomposition temperature lower and PLA matrix stable. Expansion layer after burning served an important role in against heat and oxygen.