| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1993: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1992: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Research Abstract |
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.
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