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1.研究聚异丁烯的辐射效应时,发现其裂解速度与温度关系与聚乙烯类似.这说明聚异丁烯在辐照时,除了直接因受射线作用而断链外,还可能同时进行一种由辐照时形成的自由基参加的二级反应. 2.在射线作用下形成的氢原子(由侧链CH_3-基的C-H键中断而产生),能与邻近的聚异丁烯分子的侧键CH_3-作用.由此形成的高分子自由基由于立体障碍不能起重合反应,但能起重排反应.其结果使双键产率与裂解产率的比值增加;使聚异丁烯的甲基侧链浓度下降而出现乙基支链. 3.??型高分子在溶胀状态下辐照,其裂解速度降低.这是因为当溶剂分子存在下抑制二分子重排裂解反应的缘故.共聚物??在含C~(14)甲苯中辐照后,引入高分子的放射活性随剂量增加而增加,但粘度不变.这也论证了上述假定是正确的. 4.研究了高分子量聚异丁烯级分与含C~(14)的低分子量聚异丁烯级分的混合物辐射效应.结果证明在辐照时,甲基从一聚异丁烯分子转移到另一分子上去.这结果说明聚异丁烯的辐射裂解过程,不仅是由于直接辐射效应的结果,而且还以二分子历程进行.
1. Study polyisobutylene radiation effect, found that the rate of cracking and temperature and polyethylene similar .This shows polyisobutylene radiation, in addition to directly due to the role of radiation and chain scission, it may also be a kind of by the spokes The formation of free radicals to participate in the secondary reaction .2 formed under the action of hydrogen atoms (due to the side chain CH_3-based CH bond interrupted), with the adjacent polyisobutylene molecule side effects CH_3-role The resulting polymer radicals, due to steric hindrance, do not act as coincident but act as rearrangements, resulting in an increase in the ratio of double bond yields to cleavage yields, a decrease in the methyl side chain concentration of polyisobutylene There ethyl branch.3.???????????????????????????????????????????????????????????????????????????????????????????????????????????????) ~ (14) After irradiation, the radioactivity of the introduced polymer increased with the increase of the dose, but the viscosity was unchanged.This also proves that the above assumption is correct.4.Studies on the high molecular weight polyisobutylene fraction and containing C ~ (14) low molecular weight polyisobutylene fraction of the spokes Effect. Upon irradiation results demonstrate methyltransferase from a polyisobutene molecule to another molecule up. This results show polyisobutylene radiation process, not only as a result of direct radiation effects, but also with two molecules process.