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

天然存在的聚合物及其复合材料再次被视为可再生资源。近年来，一些研究者报道了从单糖和氨基酸等重复单元合成大分子的方法。本文以L-古洛糖酸内酯为原料，合成了两种二醇（2，3-和5，6-O-异亚丙基-L-古洛糖酸-1，4-内酯（1和2））。通过糖衍生的二醇（1和2）与L-赖氨酸衍生的二异氰酸酯、（S）-2，6-二异氰酸基己酸甲酯（3）的加聚和随后的脱异亚丙基反应，合成了在侧基和主链中具有内酯基团的新聚氨酯（4，5，6，7）。在27℃、pH值为8.0或7.0的缓冲溶液中，含内酯侧基（4和6）的聚氨酯比主链含内酯侧基（5和7）的聚氨酯水解得快。通过L-丝氨酸甲酯与3-羟基苯甲酸酯的加成反应，合成了另一种新的聚氨酯聚合物--聚（脲）（8）。它们也在pH值为8.0或7.0的缓冲溶液中水解，尽管8的水解速率远低于聚氨酯（6和7）的水解速率。

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).