硼酸锌和镁铝水滑石对硅橡胶泡沫性能的影响

Effect of Different Contents of Zinc Borate and Mg-Al Hydrotalcite on Flame Retardancy of Silicone Rubber Foams

采用室温脱氢法制备了以硼酸锌(ZB)和水滑石(LDH)为阻燃剂的阻燃硅橡胶泡沫(SiF)。对其力学性能进行了测试,并且通过极限氧指数(LOI)、UL-94试验、热重分析、锥形量热仪(CONE)和烟密度测试,研究了SiF的阻燃性能和抑烟性能。结果表明,SiF的阻燃抑烟性能、力学性能及热稳定性明显提高。添加2%ZB和1%LDH的SiF的LOI为31.4%,达到UL94-V0等级,热释放速率(HRR)和热释放总量(THR)分别降低了22.2%和30.4%。烟密度测试表明,添加ZB和LDH后,最大烟密度(MSD)和烟密度等级(SDR)均有降低。另外,含2%ZB和1%LDH的SiF的拉伸强度提高了57.9%,断裂伸长率提高了44.8%。添加ZB和LDH之后SiF复合材料具有良好的热稳定性和更致密的炭层。综合考虑,含2%ZB和1%LDH的SiF在阻燃、热稳定性及力学性能方面表现出优良的综合性能。

The flame retardant silicone rubber foams(SiF)with zinc borate(ZB)and hydrotalcite(LDH)as flame retardant were prepared through dehydrogenation at room temperature.The flame retardance,smoke suppression,mechanical properties,and thermal stability of SiF with ZB and LDH were investigated through the limiting oxygen index(LOI),UL-94 test,cone calorimeter,thermogravimetry,and smoke density test.The results show that the flame retardant and smoke suppression properties,mechanical properties and thermal stability of SiF are improved obviously.With 2%ZB and 1%LDH,the SiF composite achieves the UL-94 V-0 rating,and has an LOI value of 31.4%.And the heat release rate(HRR)and total heat release(THR)of SiF with 2%ZB and 1%LDH are decreased by 22.2%and 30.4%,respectively.The smoke density test results show the maximum smoke density(MSD)and smoke density rating(SDR)are decreased with the addition of ZB and LDH.In addition,the tensile strength and elongation at break of the SiF composite with 2%ZB and 1%LDH are increased by 57.9%and 44.8%,respectively.After adding ZB and LDH,SiF composites have good thermal stability and denser carbon layer.Considering comprehensively,the SiF composite with 2%ZB and 1%LDH exhibits excellent comprehensive properties in flame retardant,thermal stability and mechanical properties.