介孔分子筛和Cr2O3协同膨胀阻燃体系对阻燃天然橡胶性能的影响
Synergistic effects of mesoporous molecular sieve and Cr2O3 with intumescent flame retardant on properties of flame-retarded natural rubber

用介孔分子筛（MCM-41）和Cr2O3协同膨胀型阻燃体系（IFR）对天然橡胶（NR）进行阻燃。为研究MCM-41和Cr2O3的阻燃协同作用，使用不同组分的两种协效剂协同IFR阻燃天然橡胶。对阻燃体系分别进行氧指数测试、热重分析、锥形量热分析、拉伸测试和残炭扫描分析。研究结果表明：天然橡胶单纯添加IFR时，其力学性能大幅下降，热学性能也没有显著提升。然而随着Cr2O3和MCM-41添加量的增加，橡胶基体的拉伸强度和断裂伸长率均有所改善，在IFR添加量为36%（与天然橡胶的质量比）、MCM-41添加量为1%，Cr2O3为3%时，IFR-MCM-41-Cr2O3复合阻燃剂的阻燃效果最好，热释放速率峰值和热释放总量均明显下降，IFR-MCM-41-Cr2O3/NR复合材料燃烧后，炭层发泡均匀且致密，极限氧指数（LOI）可以达到26.5%，垂直燃烧（UL-94）为V-0级。 Mesoporous molecular sieve(MCM-41) and Cr2O3 were used on intumescent flame retardant (IFR) to flame retardant natural rubber(NR). In order to study the flame retardant synergistic effects of MCM-41 and Cr2O3, two synergists of different components and IFR were used to flame retardant natural rubber(NR). The oxygen index test, thermogravimetric analysis, cone calorimetric analysis, tensile test and the analysis of the residual carbon scanning were investigated for the flame retardant system. The results show that when only expansion flame retardant system is added to the natural rubber, the mechanical properties of the flame retardant system are dropped dramatically and the thermal performance almost have no improvement. While tensile strength and elongation at break of the composites are improved with the increase of Cr2O3 and MCM-41. The IFR-MCM-41-Cr2O3 composite flame retardant effect achieves the best when IFR content is 36% (mass ratio to the natural rubber), MCM-41 content is 1%, Cr2O3 content is 3%. And the peak value of heat release rate and total heat release of burning decrease significantly. The IFR-MCM-41-Cr2O3/NR composites could form compact charred layer after burning. The limiting oxygen index (LOI) can reach 26.5% and the vertical combustion (UL-94) is V-0 level. 辽宁省自然科学基金（2015021016）；沈阳市科技局国际合作项目（f15-200-6-01）；辽宁省百千万人才工程（[2017]62）