生物基三组分自组装涂层构筑及其对苎麻织物的阻燃改性

Construction of bio-based three-component self-assembled coating for flame retardancy of ramie fabrics

为解决苎麻纤维易燃烧和使其增强复合材料阻燃性降低的问题,采用层层自组装方法,以生物质来源的海藻酸钠(SA)、聚双酚酸苯基磷酸酯(poly(DPA-PDCP))为聚阴离子电解质,聚乙烯亚胺(PEI)为聚阳离子电解质,在苎麻织物表面构筑了(SA/PEI/poly(DPA-PDCP)/PEI)n三组分阻燃涂层,借助傅里叶红外光谱仪、扫描电子显微镜、热失重分析仪、微型量热仪、垂直燃烧测试仪等对其形貌、热稳定性和阻燃性能进行表征。结果表明:苎麻织物表面构筑了一个多层、厚且致密的(SA/PEI/poly(DPA-PDCP)/PEI)n阻燃涂层,该阻燃涂层可明显降低苎麻织物的热分解速率,燃烧时在其表面形成一层厚且致密的膨胀型阻燃炭层,可有效地隔热隔氧,提高苎麻织物的热稳定性和成炭能力,并赋予其优异的阻燃性能,解决苎麻增强复合材料阻燃性能差的问题。

In order to solve the flammability of ramie fibers and their reinforced composites,sodium alginate(SA)and poly(diphenolic acid-phenyl phosphate)(poly(DPA-PDCP))from biomass were used as the polyanion electrolyte and polyethyleneimine(PEI)as the polycation electrolyte,three-component(SA/PEI/poly(DPA-PDCP)/PEI)n flame retardant coating was constructed on the surface of ramie fabrics by layer-by-layer assembly technique.The morphology,thermal stability and flame retardancy of the coating and hence the coated fabrics were characterized using Fourier transform infrared spectroscopy,scanning electron microscopy,thermogravimetric analyzer,microscale combustion calorimetry,vertical combustion tester.The experimental results show that a multi-layered,thick and dense(SA/PEI/poly(DPA-PDCP)/PEI)n flame retardant coating is successfully constructed on the surface of ramie fabrics.This flame retardant coating reduces significantly the thermal decomposition rate of ramie fabrics,forming a thick and dense intumescent flame retardant carbon layer on its surface,which insulates effectively the heat and oxygen,improves its thermal stability and carbon forming ability,and gives the ramie fabrics excellent flame retardancy.This research demonstrates a solution to the problem of poor flame retardancy of ramie reinforced composites.