硅烷偶联改性海泡石对三元乙丙橡胶性能的影响

利用酌-甲基丙烯酰氧基丙基三甲氧基硅烷（KH-570） 对提纯海泡石矿物进行表面改性，制备成橡胶补强填料. 研究改性海泡石补强三元乙丙橡胶力学性能的变化规律，借助傅里叶红外光谱（FTIR）、光电子能谱（XPS）、热分析（TG-DTA） 和扫描电镜（SEM），探讨改性海泡石对复合橡胶的补强机理. 结果表明：当偶联剂添加量为海泡石质量的4%时，填充复合橡胶的力学性能达到最好，与未改性海泡石填充复合橡胶相比，其拉伸强度提高了51.25%，扯断伸长率降低了17.89%. 偶联剂官能团以物理包覆和化学键合两种方式存在于海泡石 纳米纤维的表面，其化学接枝率约为38.3%.海泡石表面Si2p 和O1s 的电子结合能分别减少了0.22eV 和0.78eV，说明O 原子的化学位移较大，接枝反应发生在Si-OH 中的O 原子上. 改性后海泡石表面接枝的有机官能团能使其在三元乙丙橡胶（EPDM） 中拥有更好的相容性和分散性.
The performance change law of modified sepiolite filled ethylene propylene diene monomer (EPDM) rubber was investigated via the modification of γ-methacryloxypropyl trimethoxy silane (KH-570) for sepiolite. The reinforcement mechanism of modified sepiolite for the composite rubber was analyzed by means of infrared spectroscopy (FTIR), photoelectron spectroscopy (XPS), thermal analysis (TG-DTA) and scanning electron microscopy (SEM), respectively. The resultshows that the mechanical property of filler composite rubber is superior at the addition of coupling agent of 4%. Compared with the EPDM filled with sepiolite, which was not modified, the tensile strength was increased by 51.25 and the elongation at break was reduced by 17.89%. The KH-570 exists on the surface of modified sepiolites by two ways of physically coat-ing and chemically bonding. its chemical grafting rate is about 38.3%. The binding energy of Si2p and O1s decreases by 0.22 eV and 0.78 eV, which indicates that the grafting reaction occured in O atoms of Si-OH groups due to the larger chemical shift of O atoms. It also shows that the functional groups on the surface of sepiolite bring it with better compatibility and dispersibility in EPDM.