氯化聚乙烯辐射效应的NMR研究

Irradiation Effects on Chlorinated Polyethylene Studied by NMR Spectroscopy

用1H NMR,13C NMR谱,二维谱,FT-IR等方法研究了氯化聚乙烯(CPE)在室温下限量空气中经60Coγ射线辐照后的辐照效应.结果表明CPE在辐照过程中以发生裂解反应为主,在裂解反应过程中伴随着HCl脱出,HCl的脱出量随着辐照剂量的增加而增加.辐照后CPE样品的大分子结构发生相应变化,序列结构为CH2CHClCHClCH2CHCl,CH2CH2CHClCH2CH2,CHCl CH2CHClCH2CH2,CHClCH2CHClCH2CHCl的单元数量减少,但没有形成新的序列结构类型,T1和T2值给出了有关辐照前后分子运动变化的信息.

Irradiation effects on chlorinated polyethylene （CPE） were studied by 1D and 2D NMR spectroscopy, measurements of proton spin-spin relaxation time （T2） and spin-lattice relaxation time （T1） and FT-IR. The results indicated that degradation reactions took place after CPE was irradiated by 60 Co γ-rays. It was shown that HCl emitted during irradiation. The higher the absorbed doses was, the more HCl emitted. The quantity of some sequential structures （e. g. , CH2 CHClCHClCH2 CHCl, CH2CH2CHClCH2CH2, CHClCH2CHClCH2CH2, and CHClCH2CHClCH2CHCl） of CPE were found reduced after irradiation, but there were no evidence indicating that new sequential structures were formed. The values of T1 and T2 also provided very important information about the segmental motion of the molecules.