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通过凝胶和溶胶分析与分子量测定的方法,研究了不同体系下,“OH对PDMS乳液γ辐射效应的影响.结果表明,”OH不仅可引发聚二甲基硅氧烷的分子间交联,也能促进其降解.对于纯PDMS乳液,在所研究的剂量范围内,“OH对其辐射交联行为影响较小.但若体系中加入H2O2、KIO4和N2O这些提高”OH生成产额的添加剂时,“OH对PDMS的促降解作用会随着吸收剂量增加而表现更明显,导致凝胶含量与纯乳液辐照情况相比下降较多.即使加入交联剂-三羟甲基丙烷三甲基丙烯酸酯(TMPTMA),在过量的”OH存在下,当吸收剂量大于40kGy以上时,TMPTMA不仅没有提高交联度,反而会与“OH协同,使PDMS的凝胶含量下降更显著,同时产生更多的小分子聚合物,并使PDMS的平均分子量分布变窄.这可能是由于交联剂首先与”OH作用,形成的产物会加快PDMS的降解.
The effects of “OH” on γ radiation of PDMS emulsion were investigated by means of gel and sol-gel analysis and molecular weight determination. The results show that “OH” can not only induce intermolecular interaction of polydimethylsiloxane For pure PDMS emulsions, “OH” has little effect on the radiation cross-linking behavior in the range of doses studied, but if the system incorporates H2O2, KIO4 and N2O, Yield of additives, “OH on the degradation of PDMS degradation will increase with the absorbed dose is more obvious, resulting in gel content and pure emulsion irradiation compared to the situation even more added. Even with the crosslinking agent - trihydroxyl In the presence of an excess of ”OH“, TMPTMA not only did not increase the degree of crosslinking but also synergized with ”OH“ in the presence of an excess of ”OH“ to render the PDMS gel The decrease of the content is more significant, more small molecule polymers are produced at the same time, and the average molecular weight distribution of PDMS is narrowed.This may be due to the crosslinking agent first interacting with ”OH, the formation of the product will accelerate the degradation of PDMS.