| High pure octavinylsilsesquioxane(OVS) was prepared using vinyltrichlorosilane as raw material without catalyst, and peracid was employed as oxidant to prepare epoxyethylvinylsilsesquioxane(EVS). The structure of two products was confirmed by FTIR, NMR and MS. OVS has a crystal system of primitive orthorhombic and melts at 351℃by XRD and DSC. The effect of reaction conditions on yield were studied, that the condensation of silanol is a slow equilibrium reaction with water catalyst, and the product ratio is decided by the temperature and monomer concentration. A well yield can be made under an optimal conditions. Temperature is also the key of reaction degree in epoxidation of OVS, and the EVS has the most epoxy content at 70℃.On the basis of above research, OVS-acrylate copolymeric emulsion of various organosiloxane content was synthesized by a semi-continuous polymerization. NMR and FTIR results show that the net of acrylate is crosslinked by the node of OVS. OVS can improve the polymerization of acrylate, but the ascending crosslinking degree reduce the stability of emulsion. The particle size distribution is narrow with the little effect of OVS on average particle. As the addition of OVS, Tg and water resistance of emulsion film ascend. The tensile strength increase too, while the rupture elongation decreased slightly. |
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