合成工艺对PCL型水性聚氨酯性能的影响

Effect of synthetic process on properties of PCL waterborne polyurethane

以异佛尔酮二异氰酸酯、聚己内酯二醇为原料,二羟甲基丙酸为亲水剂,1,4-丁二醇、三羟甲基丙烷为扩链/交联剂,在聚合物异氰酸根指数为1.10、亲水扩链剂用量占树脂总质量5%、扩链/交联剂用量占树脂总质量3%的条件下制备了水性聚氨酯乳液,探讨了不同合成工艺对水性聚氨酯乳液及膜性能的影响。结果表明:采用预聚→引入亲水基→扩链/交联→中和→乳化工艺制备的水性聚氨酯综合性能最优,乳液粒径分布较窄,平均粒径较小,Zeta电位绝对值最高,乳液稳定性较好;膜的软硬段微相分离程度增大,拉伸强度明显增强,吸水率明显降低。

Isophorone diisocyanate and polycaprolactone glycol were used as main raw materials,dimethylol propionic acid as hydrophilic agent,1,4-butanediol and trimethylolpropane as chain extender/cross-linker to prepare waterborne polyurethane emulsion under the conditions as the isocyanate index of polymer is 1.10,the mass fraction of hydrophilic chain extender and the chain extender/crosslinking agent in polymer are 5%and 3%,respectively.The effects of different synthetic processes on properties of emulsion and membrane were investigated.The results show that the properties of waterborne polyurethane prepared by prepolymerization→introduction of hydrophilic group→chain extension/crosslinking→neutralization→emulsific ation are the best,the particle size distribution is narrow,the average particle size is small,and the Zeta potential is the highest absolute value,the stability of the emulsion is better.The degree of microphase separation in the hard and soft segments of the membrane is increased,its tensile strength is increased and its water absorption is decreased obviously.