Syntheses of Functional Polymers Using Natural Products and Their Applications.

从新型功能聚合物应与自然环境相协调的观点出发，合成了由天然产物衍生的新型水溶性光功能聚合物，并对其应用进行了研究。聚乙烯醇（PVA）与甲基乙烯酮（MVK）在碱的存在下反应，合成了含有饱和羰基和α、β -不饱和羰基的PVA （PCPVA）。经254nm紫外光照射后，PCPVA薄膜不溶于水。从PCPVA光过程的光谱分析中发现，悬垂的α、β不饱和羰基的光二聚化作用诱导了PCPVA的不溶化作用。研究了淀粉、甲基纤维素、普鲁兰等含羟基的天然聚合物及其衍生物的反应。α、β -不饱和羰基很容易被引入到这些聚合物中，并且光交联过程类似。虽然普鲁兰衍生物（PCPln）的薄膜与PCPVA一样坚韧，但淀粉和甲基纤维素衍生物的薄膜却很脆。PCPln可被普鲁兰酶生物降解。发现PCPVA在醋酸钠存在下热不溶。光谱分析表明，交联反应是由α、β -不饱和羰基与饱和羰基醛醇缩合而成。从其结构来看，PCPln的热交联也可能发生类似的情况。从这些结果来看，天然聚合物作为水溶性光功能聚合物的资源是非常有前途的。

From the view points that new functional polymers should be in harmony with natural environment, new water soluble photo-functional polymers derived from natural products were synthesized and its applications were investigated.When poly (vinyl alcohol) (PVA) was reacted with methyl vinyl ketone (MVK) in the presence of a base, PVA bearing saturated carbonyl groups and alpha, beta-unsaturated carbonyl groups (PCPVA) was synthesized. Thin films of PCPVA upon UV irradiation at 254nm were found to become insoluble in water. From specteral analysis of photo-process of the PCPVA,photodimerization of pendant alpha, beta-unsaturated carbonyl groups was found to induce the insolubilization. The reaction of natural polymers and their derivatives which have hydroxy groups such as starch, methylcellulose, and pullulan were also investigated. alpha, beta-Unsaturated carbonyl groups were easily introduced in these polymers, and the photocrosslinking proceeded similarly. Although films of derivatives of pullulan (PCPln) were tough as well as those of PCPVA,films of derivatives of starch and methylcellulose were very brittle. PCPln was proved to bio-degrade by pullulanase.The PCPVA was found to be insolubilized thermally in the presence of sodium acetate. From spectral analysis, it was clarified that the crosslinking proceeded by aldol condensation of alpha, beta-unsaturated carbonyl groups with saturated carbonyl groups. Thermal crosslinking of PCPln is expected to occur similarly from their structure.From these results, natural polymers were found to be very promising as the resources for water soluble photo-functional polymers.