可生物降解氨基酸衍生拟聚碳酸酯与聚乙二醇600共混的加速水解研究

Accelerated hydrolysis of L-tyrosine-derived biodegradable polycarbonate/polyethylene glycol 600 blend samples

目的:为改善可降解生物材料拟聚碳酸酯的水解状况,将亲水的聚乙二醇作为共混组分制备共混试样,观察混合物的热性质和水解率。方法:①用界面聚合法制备了一种新的拟聚氨基酸-酪氨酸衍生聚碳酸酯,并用溶液共混合法制备了L-酪氨酸衍生聚碳酸酯与相对分子质量为600的聚乙二醇,以不同质量比混合的混合物试样。②用傅里叶红外、核磁共振法表征了混合物的结构;用示差扫描量热法,热重分析表征了混合物的热性质;并将试样置于浓度为1mol/L的碱液中进行加速水解测试。结果:随着PEG聚乙二醇质量分数的增加,混合物的玻璃化转变温度逐渐降低;同时降解率随聚乙二醇质量分数的增加而增加,混合物的水解率增大;混合物的水解对降解环境pH值影响较小。结论:聚乙二醇的引入,有效改善了聚碳酸酯的热性能,同时增加了聚碳酸酯的亲水性,混合物的降解速率明显大于聚碳酸酯。

AIM： Biodegradable polycarbonate is blended with hydrophilic polyethylene glycol （PEG） to improve the hydrolytic property of biodegradable ＇pseudo＇ polycarbonate. And the thermal property and hydrolytic property of the blends are observed. METHODS： ①A novel ＇pseudo＇ poly tyrosine derived polycarbonate was synthesized by interfacial polycondensation. L-tyrosine-derived polycarbonate was blended with PEG of 600 molecular mass according to different mass ratios by solution blend method.②Chemical structure of blend polymer was confirmed by nuclear magnetic resonance and fourier transform infrared spectroscopy. The thermal property was determined by differential scanning calorimeter and thermogravimetric analysis; The accelerated hydrolysis of the blend samples was performed in alkaline condition （1 mol/L concentration）. RESULTS： The glass transition temperature decreased with increasing PEG content. The degradation of blends increased with increasing PEG content. The hydrolysis of blend samples showed slight effect on pH value of degradation environment. CONCLUSION： The thermal property and hydrophilicity of polycarbonate can be improved by introducing PEG. The degradation rate of blend samples is significantly higher than that of polycarbonate.