水溶性高分子对聚紫罗精光致变色性能的影响

用光谱法研究了四种水溶性高分子(聚乙烯吡咯烷酮PVP、聚乙烯醇PVA、明胶、聚丙烯酰胺PAM)对聚丁基紫罗精溴化物(PBV)的光致变色行为的影响。PBV的变色(还原)速率按PVP>明胶>PVA>PAM的顺序递减。在聚乙烯醇介质中,PBV的还原为二级反应。测定了暗回复(退色)速率,发现其服从一级反应规律,用电子顺磁共振法得到同样的结果。     

PHOTOREDUCTION OF ALKYL VIOLOGENS AND POLYVlOLOGENS IN 2-PROPANOL AQUEOUS SOLUTION

In order to study the effect ofalkyl chain length and the polymer effect on the photoreduction behavior of some viologens, a series of alkyl viologen, polyviologen and bisviologen compounds have been synthesized. In the presence of excess 2-propanol, the initial photoreduction of alkyl viologens and polyviologens follow the peudo--seeond--order reaction, the calculated rate constants are related to the alkyl chain length: In addition, the intramoleeular association of radical cations of polyviologens has been found even in dilute solution. However the extent of association is varied with the aikyl chain length. The observed polymer effect of polyviologens in the photoreduetion is significant which can be explained in terms of the nature of second order reaction.     

含PVA感光树脂的热表征

本文用差示扫描量热法(DSC)对含PVA感光树脂进行热表征。结果表明,DSC可以作为含PVA感光树脂的感光性能和稳定性能的质量控制手段。     

甲基丙烯酸β羟乙酯的感光聚合动力学的研究

本文用自动记录膨胀计研究了在紫外光照射下30℃时,以安息香醚类作光敏剂,甲基丙烯酸β-羟乙酯(HEMA)的感光聚合反应动力学。测得了在水溶液中,以羟甲基安息香甲醚或安息香乙醚作光敏剂时,单体的起始聚合速率与光敏剂浓度、单体浓度及起始光强的关系。动力学的研究表明:聚合速率与光敏剂浓度及起始光强有平方根的依赖关系,这近似于一般的游离基聚合的动力学规律,但是单体的反应级数远小于1。根据动力学的研究,得到了聚合反应动力学方程式,并讨论了其聚合反应历程。同时研究了温度、溶剂对聚合速率及暗反应聚合速率的影响,井计算了其感光聚合总活化能(E_p-E_t/2)值接近于零。