聚乳酸/有机磷共混纤维阻燃改性及性能研究

Study on Flame-Retardant Modification and Properties of Polylactic Acid/Organophosphorus Blend Fiber

针对聚乳酸(PLA)易燃烧的缺点,选择高效绿色脂肪族有机磷(OP)为阻燃剂,通过熔融共混与熔纺成形技术制备PLA-OP复合材料及纤维,全面分析了OP对PLA-OP复合材料热稳定性能、阻燃性能、阻燃机制及力学性能的影响规律,结果显示:OP与PLA具有良好的相容性,且PLA-OP复合材料热稳定性良好,完全满足高温熔融加工要求;同时,OP可显著提升PLA的阻燃性能,当OP质量分数为4%时,材料垂直燃烧等级由纯PLA的NR等级提升至V-1等级,极限氧指数由纯PLA的22.6%提升至29.1%。由热失重-红外联用、扫描电镜与拉曼光谱分析可知:OP兼具气相阻燃与凝聚相阻燃作用,其在高温燃烧过程中起到催化成炭、捕捉高活性自由基、降低挥发性可燃物浓度等作用,最终有效提升PLA阻燃性能。此外,PLA-4OP熔纺纤维的断裂强度为3.6cN/dtex,满足绝大部分终端使用要求,这表明其具有良好的应用前景。

Aiming at the disadvantage that polylactic acid(PLA)was easy to burn,green aliphatic organo-phosphorus(OP)was selected as flame retardant,and PLA-OP composites and fibers were prepared by melt blending and melt spinning.The effects of OP on the thermal stability,flame retardancy and mechanical properties of PLA-OP composites were comprehensively analyzed.It is found that OP has good compatibili-ty with PLA,and PLA-OP composites exhibit excellent thermal stability,which can fully meet the require-ments of melting process.At the same time,the flame retardancy of PLA is significantly improved by OP.When the OP mass fraction is 4%,the vertical combustion grade of the material increases from NR grade of neat PLA to V-1 grade,and the limiting oxygen index increases from 22.6%of neat PLA to 29.1%.Accord-ing to thermogravimetric and infrared combined application,scanning electron microscopy and Raman spec-trum analysis,OP has both vapor-phase flame retardant and condensed phase flame retardant effects,and plays a role in catalyzing carbon formation,capturing highly active free radicals,reducing volatile fuel con-centration and so on during high temperature combustion,and finally effectively improving the flame retar-dant performance of PLA.In addition,the breaking strength of PLA-4OP melt spun fiber is 3.6 cN/dtex,which meets most of the requirements of end use,indicating that it has a good application prospect.