摘要
本文研究了GY-131医用级聚甲基乙烯基硅氧烷(PMVS)在辐照交联中的自由基产生和衰减的ESR潜,以及SiO_2填料对交联的影响。
The ESR spectra of all samples prepared in the previous paper are obtained at room and low temperature (liquid nitrogen 77K). The quartet with a hyperfine splitting of 23 gauss is due to radicals of type · CH3;the triplet with a hyperfine splitting of 22 gauss,due to · CH-Si≡ and the singlet due to ·Si≡ or · O-Si . The spectrum differs with the change in the silica filler content.The radicals produced in the irradiated PMVS are stable and decay slowly on keeping the samples at 77K or room temperature, while warming the samples from 77K to room temperature, the radical .signal becomes weaken. Furthermore,the radicals in all samples almost disappear over 100℃ for 2h or more. These samples have a stable gel content at room temperature. In this way, the radicals in radiation crosslinked PMVS can be cleared up.The radiation behavior of PMVS and the influence of silica filler on the crosslinking are also studied in present work. The radicals in silica filler are observed. These radicals may couple with the main chain scission radicals resulted from mechanical processing to form crosslinks. The coupling of radicals has more chances in radiation crosslinking process, and PMVS with filler does crosslink easier than PMVS without filler. So the enhancement of silica filler to radiation crosslinking of PMVS is mainly chemical mechanism.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
1990年第1期66-70,共5页
Chemical Journal of Chinese Universities
关键词
硅橡胶
PMVS
辐照交联
ESR谱
ESR spectra, Poly(methyl vinylsiloxane),Silica,Radiation crosslink
