天然高分子对生物聚酯P(3,4)HB复合材料阻燃性能的影响

以三聚氰胺磷酸盐(MP)和季戊四醇磷酸酯(PEPA)复配的膨胀型阻燃体系阻燃聚(3-羟基丁酸酯-co-4-羟基丁酸酯)P(3,4)HB], 分别用木质素、壳聚糖和海藻酸钠3种天然高分子作为成炭剂代替部分PEPA, 采用熔融共混法制备P(3,4)HB基阻燃复合材料。通过热重分析仪(TGA)、微型量热仪(MCC)、垂直燃烧仪(UL-94)、极限氧指数仪(LOI)及扫描电镜(SEM)等对其热稳定性、热燃烧性能、阻燃特性及炭渣形貌进行了表征与分析, 对比研究了3种天然高分子对P(3,4)HB基复合材料阻燃性能的影响。结果表明:含有木质素的复合材料体系燃烧后形成了致密而连续的炭层, 且能达到V-0级别, 而含壳聚糖或海藻酸钠的复合材料体系燃烧后形成的炭层结构多孔而疏松, 只能达到V-2级。

Influence of different natural polymers on the flame retardant property of biodegradable P(3,4)HB composites

MP, PEPA were composed to be intumescent flame retardant (IFR), then three natural polymers, lignin, chitosan and sodium alginate, were selected to substitute for part of PEPA, the flame-retardant composites based on P(3,4)HB were prepared by means of melt blending. The thermal property, combustion performance, flame retardant and residue morphology were investigated by TGA, MCC, UL-94, LOI and SEM, respectively. The results showed that the composite contained lignin formed a compact and continuous char layer after burning and can reach UL-94 V-0 level. However, the addition of chitosan and sodium alginate made the char layer porous and loose and the composites can only reach V-2 level.