聚铝硅氧烷对聚碳酸酯的阻燃作用

采用水解缩合法制备了聚铝硅氧烷，用极限氧指数、热失重分析、扫描电子显微镜、X射线光电子能谱研究了聚铝硅氧烷对聚碳酸酯（PC）的阻燃作用机理。结果表明，聚铝硅氧烷可明显提高PC的极限氧指数；在热降解过程中，聚铝硅氧烷可使PC的最大热降解速率降低，800 ℃残炭率显著提高，在PC中添加5 %（质量分数，下同）的聚铝硅氧烷可使PC的800 ℃残炭率提高44.1 %；在燃烧过程中，聚铝硅氧烷会迁移到PC表面，与PC的降解产物发生相互作用，促进残炭的形成，硅(Si)和铝(Al)积聚在材料表面形成富含Si、Al的绝缘炭层，抑制了材料的进一步降解，阻碍了热量和可燃性气体的传递，从而有效地改善了PC的阻燃性能。

Flame Retardant Effect of Polyaluminosiloxane on PC

The polyaluminosiloxane was prepared through co hydrolysis condensation.The flame retardant mechanism of the polyaluminosiloxane for polycarbonate(PC) was studied by limited oxygen index, thermogravimetric analysis, scanning electron microscopy, and energy dispersive X-ray spectroscopy(EDX). It was found that the polyaluminosiloxane improved the limiting oxygen index of PC. In the thermal degradation process with 5 mass% loading of polyaluminosiloxane, the thermal degradation rate was reduced, and the char yield at 800 ℃ was increased by 44.1 %. During the combustion process, the polyaluminosiloxane would migrate to surface and interact with PC degradation product to promote the formation of carbon residue. The accumulation of Si and Al on the surface enhanced the carbon layer which retarded further pyrolysis of the material and hinder the transmission of heat and combustible gases, and thus improved the flame retardant effect.