Photo Cross-linking of Polyvinyl Alcohol Containing Uracil

Water-soluble polyvinyl alcohol (PVA) was modified by uracil derivatives which gave photodimer by UV irradiation. Photo cross-linking of the polymer (PVA-Ura) was carried out in film state on quarz plate by irradiation at 265nm. Photo cross-linking of the polymer was evaluated by development in water The cross-linking was found to be affected by irradiated energy, degree of polymerization of PVA, and kind of uracil derivatives used. High sensitivity was obtained for the polymer having high degree of polymerization. Cross-linking occured at low conversion of photodimerization (1-3%).This result indicated that photodimerization of one uracil unit in one polymer chain caused effective cross-linking of the polymer