【作者】 许东颖；

【导师】 苏涛；

【作者基本信息】 广西大学 ， 应用化学， 2003， 硕士

【摘要】 本文主要研究了以下内容：(1)低聚合度聚醋酸乙烯酯的制备；(2)低聚合度聚醋酸乙烯酯溶液醇解和悬浮醇解工艺；(3)醋酸乙烯酯聚合机理和低聚合度聚乙烯醇结构与性能。 首先，探讨了溶液聚合法制备低聚合度聚醋酸乙烯酯过程中各种因素对聚合反应的影响。聚合温度，引发剂浓度，单体：溶剂体积比等因素，均影响低聚合度聚醋酸乙烯酯的生成，同时发现通过改变醋酸乙烯酯浓度来制备低聚合度聚醋酸乙烯酯是一个行之有效的方法。 其次，探讨了低聚合度聚醋酸乙烯酯溶液醇解工艺和悬浮醇解工艺。分析了催化剂、醇解温度、反应物浓度等对醇解度的影响。悬浮醇解法通过调节催化剂浓度、悬浮剂用量等，能有效地控制醇解度的大小，且悬浮醇解得到的聚乙烯醇产品后处理简单，生产成本低。同时，GPC结果表明两种醇解法得到聚乙烯醇的聚合度、分子量分布基本一致。 最后，对低聚合度低醇解度聚乙烯醇的结构进行了表征。FTIR和NMR表明所合成的聚乙烯醇中头-头、头-尾两种连接的方式同时并存，并据此探讨了醋酸乙烯酯的聚合机理。此外，对低聚合度聚乙烯醇的水溶性、表面张力、相变温度、拉伸强度等性能做了初步探讨。更多还原

【Abstract】 In this paper, the preparation and alcoholysis of polyvinyl acetate of low degree polymerization were studied, and the structures and properties of the resulting polymers were studied.First, the preparation of polyvinyl acetate of low polymerization through the solution polymerization method was studied. It was found that the temperature, the concentration of initiator and the ratio of vinyl acetate/solvent affect the polymerization seriously.Next, the solution alcoholysis and suspension alcoholysis process were discussed. The effect of the reaction time, temperature, the concentration of reactant and catalyst on the alcoholysis process were investigated. In the suspension alcoholysis process, the degree of alcoholysis could be efficiently controlled by changing the concentration of catalyst and suspension agent.Then, the structures of low degree of polymerization polyvinyl acetate and polyvinyl alcohol with FTIR, 1H NMR , 13C NMR and GPC were characterized. The results showed that head-head and head-tail connection coexist in either polyvinyl acetate or polyvinyl alcohol. In view of the results, we investigated the polymerization mechanism of vinyl acetate.Finally, the properties of the resulting polymers, such as solubility, tensile strength, temperature of transformation, surface tension were investigated.更多还原