论文部分内容阅读
苯乙烯及(己廾)丁烯共聚物的辐射稳定性较纯聚(己廾)丁烯的为大;而苯环的有效保护作用则与共聚物中苯乙烯的组成及其排列有关。用AlCl_3作催化剂,在-80℃——100℃下进行聚合,获得的共聚物试样溶于甲苯。采用丙酮、甲乙酮、环己酮及它们的混合液为沉淀剂作组成分级。辐照在室温下进行,用粘度法研究各不同组成的共聚物的辐射稳定性,所获得的结果如下: 1.相同克分子组成的共聚物,分级了的共聚物中苯环的保护作用较未分级的为大; 2.苯环的有效保护作用随共聚物中苯乙烯含量增加而递减,由实验数据求得下列关 系式: n=n_0e~(-bs)式中n表示共聚物中苯乙烯含量为S克分子百分数时单位苯环能保护的异丁烯个数;b是一系数(b=2.73),其值取决于共聚物中苯乙烯的排列,换言之,与阳离子共聚时键增长历程有关;n_0是当S→0时最大保护值,其值等于4。由此可见自高分子主链传向苯环的能量不能超越八个碳原子的距离进行。
The radiation stability of styrene and (hexylene) butene copolymer is larger than that of pure poly (hexylene) butylene, while the effective protection of benzene ring is related to the composition and arrangement of styrene in the copolymer. With AlCl 3 as a catalyst, the polymerization was carried out at -80 ° C to 100 ° C, and the copolymer sample obtained was dissolved in toluene. Using acetone, methyl ethyl ketone, cyclohexanone and their mixture as a precipitating agent for the composition of the classification. Irradiation was carried out at room temperature. Viscosity was used to study the radiation stability of the copolymers with different compositions. The results obtained are as follows: 1. The copolymer with the same molecular weight and the protective effect of the benzene ring in the graded copolymer Not classified as large; 2. Effective protection of the benzene ring with the increase in the content of styrene in the copolymer decreases, the experimental data obtained from the following relationship: n = n_0e ~ (-bs) Where n represents the copolymer of benzene B is a coefficient (b = 2.73), the value of which depends on the arrangement of the styrene in the copolymer, in other words, related to the growth of the bond during cation copolymerization ; n_0 is the maximum protection value when S → 0, the value is equal to 4. This shows that the energy transferred from the main polymer chain to the benzene ring can not exceed the distance of eight carbon atoms.