氯化聚乙烯辐射效应的NMR研究

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⁶⁰Co γ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，CHClCH₂CHClCH₂CH₂,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 Studied by NMR Spectroscopy

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 ⁶⁰Co 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., CH₂CHClCHClCH₂CHCl, 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.