【摘要】 以L-天冬氨酸为原料,采用热缩聚法合成聚琥珀酰亚胺。选用醇钠作为亲核试剂,开环反应得到聚(α,β-烷氧基-L-天冬氨酸)。该聚合物部分水解制备两亲性聚天冬氨酸(PAsp-Na/PAsp-R)。以聚(α,β-L-天冬氨酸丁酯)为例,利用UV、1H NMR等方法研究聚合物的水解降解行为。通过1H NMR中侧链酯基信号的消失和主链游离氨基在紫外光谱中吸光度的变化,证明水解降解过程包括侧链酯键的水解和主链酰胺键的适度裂解两部分,水解过程受环境温度和缓冲溶液pH的共同影响。水解速率具有温度响应性,环境温度越高水解速率越快(37℃时的水解速率>25℃时的水解速率)。缓冲溶液pH对聚合物降解速率的影响顺序为:pH12>pH4>pH7。更多还原

【Abstract】 Novel poly(α,β-alkoxy-L-aspartates) were successfully synthesized by nucleophilic substitution in polysuccinimide which was the thermal polycondensation product of L-aspartic acid.Amphiphilic polymer PAsp-Na/PAsp-R could be obtained by partially hydrolysis of poly(α,β-alkoxy-L-aspartates).Hydrolysis process of poly(α,β-butoxy-L-aspartates)(PAsp-B) was studied by UV spectroscopy and 1H NMR.The results showed that the degradation of PAsp-B included the rapid elimination of butyl side chains and the moderate cleavage of peptide linkages in backbone as well as that the hydrolytic properties of PAsp-B were controlled by hydrolytic environments such as temperature and pH value.The hydrolysis rate of PAsp-B in aqueous solutions decreased in the order of pH 12>pH 4>pH 7 and increased with increasing the environmental temperature(for example,the hydrolysis rate of PAsp-B was higher at 37℃ than that at 25℃).更多还原