Design of Polyurethanes and Poly(urethanurea)s Derived from Saccharides and Amino Acids and Control of Their Hydrolyzability

天然聚合物及其复合材料再次被认为是可再生资源。最近，一些研究人员报道了从单糖和氨基酸等重复单元进行大分子合成的报道。本工作以L-古龙内酯为原料合成了2，3-和5，6-0-异亚丙基-L-古龙基-1，4-内酯(1和2)。通过糖基二醇(1和2)与L-赖氨酸二异氰酸酯、S-2，6-二异氰酸甲酯(3)和脱亚丙叉反应，合成了侧链和主链上含有内酯基团的新型聚氨酯(4，5，6，7)。在pH分别为8.0时和7.0时27℃的缓冲溶液中，含侧内酯基团(4和6)的聚氨酯比主链上含有内酯基团的氨酯(5和7)的水解速度更快。通过L-丝氨酸甲酯与3的加成，合成了一种新的聚合物--L-丝氨酸甲酯(8)，它们也可以在pH值为8.0或7.0的缓冲溶液中进行水解，但8的水解率远低于聚氨酯(6和7)。

Naturally occurring polymers and their composites have been noted again as renewable resources. Recently macromolecular syntheses from their repeating units such as monosaccharides and amino acids have been reported by several investigators. In the present work we synthesized two kinds of diols (2,3- and 5,6-0-isopropylidene-L-gulono-1,4-lactones(1 and 2) from L-gulonolactone. New polyurethanes (4, 5, 6, 7) having lactone groups in the pendants and main chains were synthesized through the polyaddition of the saccharide-derived diols(1 and 2) with L-Lysine-derived diisocyanate, methyl(S)-2,6-diisocyanatohexanoate (3), and the following deisopropylidene reaction. The polyurethanes having pendant lactone groups (4 and 6) were found to be hydrolyzed more rapidly than those having lactone groups in the main chains (5 and 7) respectively, in the buffer solution of which the pH value was 8.0 or 7.0 at 27℃. The hydroxyl groups generated by the deprotection of isopropylidene groups in the polyurethanes also enhanced their hydrolyzability.Another new polymers, poly(urethanurea)s (8), were synthesized through the polyadditon of L-serine methyl ester with 3. They were also hydrolyzed in the buffer solution of which the pH value was 8.0 or 7.0 although the rate on the hydrolysis of 8 was much lower than that of the polyurethanes (6 and 7).