In-Situ Nano-Silica Reinforcing Rubber By Sol-Gel Process And Study On Reinforcing Mechanism Of EPDM

The sol-gel process is a method to prepare metal oxide by using alkoxy metal salt or metal inorganic salt. And the sol-gel technique is a novel and effective route to prepare the organic/inorganic nanocomposite. The interaction between polymers and in-situ nanoparticles can be designed, and the particle size and particle size distribution can also be controlled through this method.The in-situ silica/EPDM nanocomposite was prepared for the first time by the sol-gel process. The amount of the in-situ silica can be improved from 1.6% to 4.1% when the chloroactic acid, silica and SiR were separately introduced into in EPDM. The content of in-situ silica was measured by TG. TEM verified that in-situ silica was nanoparticle and dispersed homogenously in the EPDM matrix.The sol-gel reaction of TEOS in homogeneous phase and heterogeneous phase was studied in this paper. Also the sol-gel reaction in EPDM vulcanizte in homogenous phase and heterogeneous phase was investigated. The results showed that the effect of sol-gel reaction in EPDM in heterogeneous phase was better than that of it in homogenous phase.For the first time we found the strrain-induced crystallization in the EPDM when it was add the chloroactic acid. At the same time, the reinforcement mechanism of EPDM was studied in the thesis. The effect of the cross-linking density, kind of fillers and the loading of fillers on the tensile strength of the vulcanizate was studied. It was shown that there wasa peak in the curves of tensile strength versus the cross-linking density. And the curing time when the peaks arise was much shorter than T90. The results of this experiment hold the model of molecular slippage and the Van de Waals model.