偶联剂对天然橡胶/气相法白炭黑复合材料的硫化行为和力学性能的影响

Effect of Coupling Agents on the Vulcanization Behavior and Mechanical Characteristics of Natural Rubber/Fumed Silica Composites

用过氧化二异丙苯(DCP)硫化制得天然橡胶(NR)/气相法白炭黑复合材料。采用无转子硫化仪、力学性能测试、红外光谱(FTIR)、扫描电镜(SEM)等手段研究了硅烷偶联剂双(三乙氧基硅丙基)四硫化物(Si69)、乙烯基三乙氧基硅烷(A151)对NR/气相法白炭复合材料硫化性能和力学性能的影响。结果表明,Si69用量增加,DCP硫化NR的硫化速度指数下降,硫化时间延长,NR/气相法白炭黑复合材料的100%和300%定伸应力下降;气相法白炭黑表面因A151处理而接枝上了有机结构,当A151用量为气相法白炭黑的1.5wt%时,胶料的力学性能最佳。SEM表明,气相法白炭黑经过偶联剂Si69、A151处理后在天然橡胶内分散均匀。

Natural rubber(NR)/fumed silica composites cured with dicumyl peroxides(DCP) were prepared. The effect of coupling agents Si69 and A151 on the mechanical and vulcanization characteristics of NR/fumed silica composites was investigated by moving die rheometer(MDR), mechanical testing, FTIR and SEM. The results show that NR/fumed silica composites have lower vulcanization rate and longer vulcanization time, and the tensile stress at 100% and 300% of the blends decrease with coupling agent Si69 content increases. FTIR analysis show that the coupling agents A151 is successfully grafted onto fumed silica surface. When the amount of A151 is 1.5 wt% for fumed silica, the mechanical properties of NR/fumed silica composites are optimal. SEM show that fumed silica treated with the coupling agents Si69 or A151 is uniformly dispersed in natural rubber.