协同改性凹凸棒石对补强三元乙丙橡胶性能的影响

Effect of Synergistic Modificated Attapulgite on the Performance of Ethylene Propylene Dien Monomer

利用硅烷偶联剂和钛酸酯偶联剂协同改性凹凸棒石,研究改性凹凸棒石填充三元乙丙橡胶力学性能的变化规律,借助红外光谱以及交联密度和热分析,探讨改性凹凸棒石对复合橡胶的补强机理。结果表明:当偶联剂总添加量为凹凸棒石质量的4%,其中钛酸酯偶联剂为偶联剂总用量的45%时,填充复合橡胶的力学性能最好,与相同用量硅烷偶联剂改性凹凸棒石填充复合橡胶相比,其扯裂伸长率提高了47.78%,拉伸强度提高了27.87%,与钛酸酯改性凹凸棒石填充复合橡胶相比,其100%和300%变形时的定伸应力分别提高了72.49%和90.07%。交联密度和Fourier红外光谱分析证实:凹凸棒石表面接枝的有机官能团能促使复合橡胶网络交联结构的形成。

The performance change law of modified attapulgite filled ethylene propylene diene monomer （EPDM） rubber was investigated via the synergistic modification of silane coupling agent and titanate coupling agent for attapulgite. The reinforcement mechanism of modified attapulgite for the composite rubber was analyzed by means of infrared spectroscopy, crosslink density measurement and thermogravimetric analysis, respectively. The result show that the mechanical property of filler composite rubber is superior at the addition of two coupling agents of 4% and the addition of titanate of 45%. Compared to EPDM filled with attapulgite, which was modified with the same amount of the silane coupling agent, the elongation at break, rip elongation was increased by 47.78% and the tensile strength was increased by 27.87%. Compared to EPDM filled with attapulgite modified with the same amount of the titan- ate coupling agent, the modulus at 100% and 300% was increased by 72.49% and 90.07%, respectively. It was also indicated that the network crosslinking structure formation of composite rubber was promoted by grafting organic functional groups on the surface of attapulgite, thus leading to the decrease ofinterplanar distance of the attapulgite filled in the rubber.