醇解过程中微量水的引入对聚乙烯醇颗粒中甲醇含量的影响  

Influence of the Introduction of TraceWater on the Methanol Content of Polyvinyl Alcohol During Alcoholysis Process

作　　者：贺玉舜 周容 杨胜都 张军华[1] Yushun He;Rong Zhou;Shengdu Yang;Junhua Zhang(Polymer Research Institute of Sichuan University,State Key Laboratory of Polymer Materials Engineering,Chengdu 610065,China;Sichuan Sanlian New Material Co.,Ltd.Chengdu 610000,China)

机构地区：[1]四川大学高分子研究所高分子材料工程国家重点实验室,四川成都610065 [2]四川三联新材料有限公司,四川成都610000

出　　处：《高分子材料科学与工程》2025年第2期35-41,共7页Polymer Materials Science & Engineering

摘　　要：聚乙烯醇(PVA)的醇解以甲醇做溶剂,因此成品PVA颗粒中一般含有不低于2.0%的甲醇,如何降低PVA中甲醇含量是一个值得研究的问题。文中针对PVA 24-88中甲醇含量降低的问题,采用在醇解过程中引入少量水分的方法详细研究了干燥后PVA的醇解度及甲醇含量。结果表明,在1.0%的加水量下,PVA产物中的甲醇含量降低至0.26%。此外,详细讨论了加水量对醇解PVA样品在不同气体氛围中的热失重行为及醋酸钠含量的影响,当加水量分别为1.0%和2.0%时,醋酸钠含量仅为1.53%和1.24%,均低于无水醇解样品。同时气相色谱-质谱联用分析表明,醇解后的溶剂中甲醇和醋酸甲酯含量随加水量增加分别呈升高和降低的趋势。最后探究了干燥时间与PVA 24-88未加水醇解湿料的挥发分组成之间的关系,结果表明,随时间延长,冷凝回流组分中的甲醇和醋酸甲酯的含量分别呈现单调增加和递减趋势,且其各自含量均随干燥时间延长而逐渐降低,该结果可为聚乙烯醇实际生产难题提供指导性建议。Methanol(CH3OH)is used as solvent in the alcoholysis of polyvinyl alcohol(PVA),so the PVA particles generally contain no less than about 2.0%CH3OH.How to remove CH3OH from PVA is a problem worth studying.Aiming at the problem of CH3OH content reduction in PVA 24-88,the alcoholysis degree and CH3OH content of PVA after drying were figured out by introducing a trace water in the alcoholysis process.The experimental results demonstrate that the CH3OH content of PVA products decreases to 0.26%under the addition of 1.0%water.In addition,the effects of water addition on the thermogravimetric behavior and sodium acetate content of alcoholysis PVA in different atmospheres were discussed in detail.When the water addition is 1.0%and 2.0%,the sodium acetate content is only 1.53%and 1.24%,both lower than that of alcoholysis samples.Meanwhile,the results of GC-MS show that the contents of methyl alcohol and methyl acetate in the solvent after alcoholysis increase and decrease with the increase of water addition,respectively.Finally,the relationship between the time of drying process and volatilization of PVA 24-88 without adding water was explored.The results reveal that the percentage of CH3OH and methyl acetate in the condensation reflux component increases and decreases monotonously with the extension of time,and their respective contents gradually decrease with the extension of drying time.The results are conducive to providing guidance for the practical production problems of PVA.

关 键 词：聚乙烯醇 含水量 醇解度 溶剂组成 

分 类 号：TQ325.9[化学工程—合成树脂塑料工业]