基于NaOH中和剂制备羧酸型水性聚氨酯及其性能分析

Preparation and Performance of Carboxylic Acid Type Waterborne Polyurethane with NaOH Neutralizer

以二羟甲基丙酸(DMPA)为亲水扩链剂,与异佛尔酮二异氰酸酯、聚己二酸-1,4-丁二醇酯二醇等反应合成聚氨酯预聚体,以NaOH为中和剂,制备了一系列羧酸型水性聚氨酯(WPU)。通过观察乳液外观,测试乳液的粒径和离心稳定性及胶膜的傅里叶变换红外光谱(FTIR)、力学性能、水接触角和吸水率,探究了DMPA含量对基于NaOH中和剂的水性聚氨酯性能的影响。结果表明,采用NaOH作为中和剂制备稳定的WPU乳液,并且,随着预聚体中亲水基团含量的增加,乳液的平均粒径和胶膜的水接触角逐渐减小,水性聚氨酯膜的拉伸强度逐渐增大,当亲水基团含量为1.1%时,WPU乳液粒径为43.95 nm,胶膜拉伸强度为51.85 MPa。

A series of carboxylic acid type waterborne polyurethane(WPU)were prepared by using dimethylol propionic acid(DMPA)as hydrophilic chain extender to react with isophorone diisocyanate,poly(1,4-butanediol adipate)diol and so on to synthesis polyurethane prepolymer.The NaOH was used as neutralizer.The effect of the content of hydrophilic group on the properties of NaOH nutralizer based waterborne polyurethane emulsion and films was investigated through observation of emulsion appearance,particle size analysis,centrifugal stability test,Fourier transform infrared(FTIR),mechanical properties measurement,water contact angle and water absorption test.The results showed that stable waterborne polyurethane emulsions could be prepared with NaOH as neutralizer.With the increase of the content of hydrophilic groups in the prepolymer,the emulsion particle size and water contact angle decreased and the tensile strength of the adhesive film increased.The particle size of WPU emulsion was 43.95 nm and the tensile strength of the film reached 51.85 MPa when the hydrophilic group content was 1.1%.