【摘要】 本文报道了用介电谱法研究经γ射线辐照后固态三聚甲醛及其聚合物的分子运动和结构转变。发现三聚甲醛在45～52℃之间有一结构(晶格缺陷)变化。当温度升高时,陷落在这一缺陷中辐照产生的活性粒子(R~+)发生释放和复合。由于极性和分子运动的减弱,聚合后体系的介电损耗角正切值(tgδ)远远低于未辐照的三聚甲醛的tgδ。从tgδ与温度(T)的关系谱图上观察到单体转变为聚合物以及聚甲醛(POM)发生辐射裂解导致的分子结构的变化。更多还原

【Abstract】 The molecular motion and structure transitions of γ-irradiated trioxaneand its polymer have been studied by the dielectric measurement. It was found that therewas a change of microstructure (crystal lattice defect) in trioxane between 45℃ and55℃. Release from defect and recombination of active species (R~+) produced by radiationtook place with rise of the temperature of the system. Since the polarity and the mole-cule motion lessened after postpolymerization of irradiated trioxane, the dielectric losstangent (tgδ) Was decreased. The transition from trioxane to polyoxymethylenehas beenobserved from the dielectric spectra. The structure change of polyoxymethylene resultedfrom radiation degradation has been discussed by means of the dielectric spectrum.更多还原