水性聚氨酯结构与胶膜性能的关系

为制备一种性能优异的水性聚氨酯涂层,以聚丙二醇和异佛尔酮二异氰酸酯为主要原料,用本体聚合法制备了水性聚氨酯,考察了结构组元对胶膜性能的影响,并用激光粒度仪、微机控制电子万能试验机和同步热分析仪进行了表征。结果表明:当硬段含量增加时,乳液粒径增大,胶膜拉伸强度增加,吸水率升高;当异氰酸根指数增大时,乳液粒径增大,胶膜拉伸强度增加,吸水率降低;当亲水性扩链剂含量和中和度增大时,乳液粒径减小,胶膜的拉伸强度增加,吸水率升高;在硬段比例为50%、异氰酸酯指数为1.35、亲水性扩链剂含量为5%、中和度为1的条件下,胶膜性能较佳(拉伸强度为16MPa,断裂伸长率为556%,吸水率为6.2%)且在丙酮和甲苯中均表现出溶胀现象。

Relationship between waterborne polyurethane structure and film properties

In order to prepare a waterborne polyurethane coating with excellent properties,polypropylene glycol and isophorone diisocyanate were used as main raw materials to prepare waterborne polyurethane by bulk polymerization,and the effect of structural components on the properties of the film was investigated.It was characterized by laser particle size analyzer,microcomputer controlled electronic universal testing machine and synchronous thermal analyzer.Results showed that as the hard segment content increases,emulsion particle size,film tensile strength,and water absorption are all increase,When the isocyanate index increases,emulsion particle size and film tensile strength increase,while water absorption decreases When the content and neutralization degree of the hydrophilic chain extender increase,The emulsion particle size decreases,the tensile strength and water absorption of the adhesive film increase;Under the conditions of hard segment ratio of 50%,isocyanate index of 1.35,hydrophilic chain extender content of 5%,and degree of neutralization of 1,the film performance is better(tensile strength is 16MPa,elongation at break is 556%,water absorption is 6.2%)and swelling is exhibited in both acetone and toluene.