用反相悬浮聚合法制备膨胀型阻燃剂及其在丁苯橡胶中的应用

采用反相悬浮法聚合丙烯酸钠,同时将化学膨胀阻燃体系(IFR)三组分聚磷酸铵、季戊四醇和三聚氰胺加入到聚合体系中进行原位包裹,用傅里叶变换红外光谱对聚合产物的结构进行了表征,研究了三聚氰胺用量和聚磷酸铵与季戊四醇配比对丁苯橡胶硫化胶阻燃效果的影响,采用热重法分析了阻燃丁苯橡胶的热性能,并通过扫描电镜观察了添加IFR的丁苯橡胶在燃烧后表面的微观形态。结果表明,三聚氰胺的质量分数为IFR体系的3.0%、聚磷酸铵与季戊四醇的质量比为4.00～5.67时IFR体系的剩炭率最高,阻燃性能较好;添加IFR后丁苯橡胶的阻燃性能得到相应改善,当IFR质量分数为30%时丁苯橡胶硫化胶的极限氧指数可达27.5%;添加了IFR的丁苯橡胶硫化胶在燃烧时形成了较为致密的泡沫炭层,表明IFR对丁苯橡胶具有较好的膨胀阻燃效果。

Intumescent flame retardant prepared by inverse suspension polymerization and its application in styrene-butadiene rubber

The sodium polyacrylate-in situ encapsulated intumescent flame retardant(IFR) was prepared in the inverse suspension polymerization of sodium acrylate by adding ammonium polyphosphate,pentaerythritol and melamine,and Fourier transform infrared spectroscopy was used to characterize the structure of the flame retardant.The effects of melamine amount and the mass ratio of ammonium polyphosphate to pentaerythritol on the flame retardancy of styrene-butadiene rubber(SBR) vulcanizates were investigated,the thermal property of flame retardant SBR was studied by thermogravimetry,and the combustion surface morphology of SBR filled with IFR was observed by scanning electron microscopy.The results showed that when the mass fraction of melamine was 3.0% in IFR system,the mass ratio of ammonium polyphosphate to pentaerythritol was 4.00 to 5.67,the carbon residue yield of the system was the highest and the flame retardancy was better.The flame retardancy of SBR with IFR was improved correspondingly.When the IFR mass fraction was 30% in styrene-butadiene rubber vulcanizate,the oxygen index of the flame retardant rubber could achieve up to 27.5%;the SBR filled with IFR could form a relatively dense layer of carbon foam when it was burned,indicating that the IFR had a better intumescent flame retardant effect on SBR.