Syntheses of Functional Polymers Using Natural Products and Their Applications.

从新型功能高分子应与自然环境相协调的角度出发，以天然产物为原料，合成了新型水溶性光功能高分子，并对其应用进行了研究，以聚乙烯醇（PVA）和甲基乙烯基酮（MVK）为原料，在碱存在下合成了含饱和羰基和α，β-不饱和羰基的PVA（PCPVA）。发现PCPVA薄膜在254 nm的UV照射下变得不溶于水。通过对PCPVA光致不溶过程的光谱分析，发现侧链α，β-不饱和羰基的光二聚作用是导致不溶的主要原因。本文还对淀粉、甲基纤维素、支链淀粉等天然高分子及其衍生物的反应进行了研究。α，β-不饱和羰基容易地引入到这些聚合物中，并且光交联类似地进行。虽然普鲁兰多糖衍生物（PCPln）的膜是坚韧的，以及那些PCPVA，淀粉和甲基纤维素的衍生物的膜是非常脆的。PCPln可被普鲁兰酶降解，而PCPVA在乙酸钠存在下不溶于热。从光谱分析，它被澄清，通过α，β-不饱和羰基与饱和羰基的羟醛缩合进行交联。从结构上看，PCPln的热交联反应也是相似的，因此，天然高分子是制备水溶性光功能高分子的理想材料。

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.