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角度出发，合成了源自天然产物的新型水溶性光功能聚合物并对其应用进行了研究。以聚乙烯醇（PVA）与甲基乙烯基酮（MVK）在碱存在下反应，合成了带有饱和羰基和α、β-不饱和羰基的PVA（PCPVA）。发现 PCPVA 薄膜在 254 nm 紫外线照射下变得不溶于水。通过对PCPVA光过程的光谱分析，发现侧链α、β-不饱和羰基的光二聚作用会引起不溶化。还研究了具有羟基的天然聚合物及其衍生物（例如淀粉、甲基纤维素和普鲁兰多糖）的反应。 α，β-不饱和羰基很容易引入到这些聚合物中，并且光交联进行得类似。尽管普鲁兰多糖(PCPln)衍生物的薄膜与PCPVA一样坚韧，但淀粉和甲基纤维素衍生物的薄膜非常脆。 PCPln 被证明可以被支链淀粉酶生物降解。发现 PCPVA 在乙酸钠存在下热不溶。由光谱分析可知，交联是通过α，β-不饱和羰基与饱和羰基的羟醛缩合进行的。从结构上看，PCPln 的热交联预计会发生类似的情况。从这些结果来看，发现天然聚合物作为水溶性光功能聚合物的资源非常有前途。

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.