Study On Bulk Polymerization And Copolymerization Of BMA At High Temperature

In this paper, the effects of O2and mercaptans on BMA bulk polymerization at high temperature was studied, and so did the bulk copolymerization of BMA and HFBMA, and the properties of the copolymer were also investigated.Firstly, PBMAP was synthesized by the copolymerization of O2and BMA. PBMAP was characterized by means of NMR, FTIR, EL, DSC, etc. The effect of PBMAP on BMA bulk polymerization at high temperature was investigated. Then, the BMA bulk polymerization was conducted with cyclohexyl mercaptan, n-hexyl mercaptan and n-octylmercaptan as a chain transfer agent respectively at high temperature. The mechanism of initiating radical polymerization by mercaptan was concluded. The copolymerization of BMA and HFBMA was carried out at high temperature and p (BMA-co-HFBMA) was prepared and the performance of p (BMA-co-HFBMA) was also investigated.The results showed that the PBMAP is prepared and its molecular weight increased with the improving of oxygen partial pressure and reaction temperature. The structure of PBMAP is randomly copolymerized by BMA monomer and oxygen. The PBMAP can initiate free radical polymerization above its decomposition temperature. The chain transfer constants of mercaptans and the kpapp of polymerization were calculated. N-hexyl mercaptan and n-octylmercaptan could initiate BMA radical polymerization after chain transfer, but the cyclohexylmercaptan could not. The bulk copolymerization of HFBMA and BMA could be carried out. The monomer reactivity ratios and copolymer composition curve were calculated. The refraction index, glass transition temperature and initial decomposition temperature of the copolymer is about1.409-1.483,21℃-46℃,260℃-280℃respectively. The copolymer has a good performance of light transmittance.