分子筛/受阻胺对膨胀阻燃聚丙烯的协同阻燃作用

采用热失重、极限氧指数、锥形量热研究了以受阻胺(NOR116)和分子筛为协效剂,与聚磷酸铵(APP)/季戊四醇(PER)在聚丙烯基体中的热降解行为及协同阻燃性;并用拉曼光谱和扫描电镜分析了残炭的结构和形貌,进一步研究了其协同阻燃机理。结果表明,NOR116/分子筛协效阻燃体系可明显提高极限氧指数并改善燃烧时熔滴缺陷,显著降低热释放速率、烟释放速率;NOR116可有效提高PP的初始分解温度及最大分解速率温度,使膨胀阻燃体系后期的交联成炭及气体释放更加匹配;在燃烧过程中分子筛与膨胀阻燃体系形成了Si-P-Al-C的结构,可有效稳定炭层;拉曼光谱及扫描电镜结果表明,NOR116和分子筛可促进膨胀阻燃体系形成致密且高石墨化程度的炭层,有效阻隔了氧气的进入及热的反馈。

Synergistic Effect of Zeolite and Hindered Amine Containing Substances on Intumescent Flame Retardant Polypropylene

A series of synergistic flame retardancy polypropylene (PP) composed of ammonium polyphosphate (APP) and pentaerythritol(PER) were prepared by melting blending.The synergistic effect of zeolite and hindered amine containing substances(NOR116) was studied to improve the flame retardancy of PP intumescent system composed of APP and PER.The flame retardancy of PP composites was investigated by limiting oxygen index (LOI),UL-94 standard,thermogravimetric analysis (TGA) and cone calorimeter tests.According to LOI and UL94 test,the optimum loading of zeolite and NOR116 is 2.0％ and 0.5％,respectively.The synergistic effect of NOR116/zeolite dramatically increases the LOI and overcame the molten drops.The sample PP-11 shows the highest LOI (42％),lowest maximum heat release rate (HRR) and lowest total heat release rate (THR) value.The Raman spectroscopy and SEM results show that the NOR116/zeolite reinforce the integrity of char which improves its barrier effect as well as increases the char yield.