羧甲基壳聚糖在不同介质中的降解性能

Degradation Properties of Carboxymethyl Chitosan in Different Media

研究了羧甲基壳聚糖在磷酸盐缓冲液和0.01 mol/L NaOH水溶液中的降解.用乌氏黏度计测定了样品的分子量,用红外光谱分析了样品的分子结构.考察了分子量、质量、熔点的变化规律及羧化度对降解性能的影响,建立了降解动力学方程.结果表明,样品分子量、质量和熔点均随着时间的增加而降低,降解前后分子结构无变化.降解过程中,羧甲基壳聚糖在0.01 mol/L NaOH水溶液中的降解速度均比在磷酸盐缓冲溶液中快.分子量-时间动力学方程符合线性函数,质量-时间和熔点-时间动力学方程均符合指数函数.

Carboxymethyl chitosan was degraded in phosphate buffer and 0.01 mol/L NaOH aqueous solution.The molecular weight of the sample was determined by Obblehode Viscometry.The molecular structure was analyzed by infrared spectrum.The change of molecular weight,mass,and melting point were investigated for carboxymethyl chitosan.The kinetic equations between molecular weight,mass as well as melting point and degradation time were established.The results indicate that molecular weight,mass and melting point decrease gradually with increase of time.The molecular structure has no change before and after degradation.During degradation,the reduction quantities of molecular weight,mass and melting point of both carboxymethyl chitosan are all higher in 0.01 mol/L NaOH aqueous solution than in phosphate buffer.This indicates that carboxymethyl chitosan degraded faster in 0.01 mol/L NaOH aqueous solution than in phosphate buffer solution.The kinetic equations of molecular weight obey linear function,and the kinetic equations of mass and melting point can be expressed with exponential function.