【摘要】 高分子量、高醇解度的聚乙烯醇(PVA)在自然环境中的生物降解性较差,难以实现水体自净化的要求。为从根本上提高PVA的生物降解性能,采用H2O2与Fe2+的复合体系对PVA进行氧化处理,使PVA分子链上的—OH部分氧化为O结构,为PVA发生主链断裂提供条件。通过对PVA的氧化动力学研究和分子量测定,确定了氧化改性的反应条件;用红外光谱法检测证明了氧化反应使PVA形成了生物降解所需的双酮结构;用紫外分光光度法对氧化改性后的PVA生物降解性进行了测定。结果表明,适当的氧化可大大提高PVA的生物降解性能。更多还原

【Abstract】 Polyvinyl alcohol（PVA） with high molecular weight and high purity is rather difficult to be bio-degraded in the natural environment and to satisfy the requirement of self cleaning of the water system.For improving its biodegradability,hydrogen peroxide and Fe²⁺ system is used to oxide the hydroxyl groups of PVA,thus facilitating the breakage of the main chain of PVA.The oxidative modification reaction conditions are determined through studying the dynamics of oxidation and measuring the molecular weight.Infrared spectrophotometry study has proved that oxidative reaction has rendered PVA the ketone-ketone structure which is necessary for biodegradation,and ultraviolet spectrophotometry is used to determine the biodegrability of the modified PVA.The results indicate that proper oxidation of PVA can significantly improve its biodegradability.更多还原