原料配比对水性聚氨酯耐水及力学性能影响的研究

Effect of Raw Material Ratio on Water Resistance and Mechanical Properties of Waterborne Polyurethane

以异佛尔酮二异氰酸酯(IPDI)、聚氧化丙二醇(PPG)、三羟甲基丙烷(TMP)、二羟甲基丙酸(DMPA)等为主要原料,采用预聚体分散法制备水性聚氨酯(WPU)系列产品,通过对产品性能的分析与表征,研究中和度、异氰酸根指数(R值)、亲水剂用量、交联剂用量等因素对WPU耐水及力学性能的影响。结果表明:随着中和度增大,胶膜拉伸强度增加,吸水率增大;随着R值增大,拉伸强度增大,胶膜吸水率减小;随着亲水剂用量的增加,胶膜拉伸强度、吸水率均增大;随着交联剂用量的增加,胶膜拉伸强度先增大后减小,吸水率先减小后增大。正交试验结果显示,影响WPU膜吸水率因素顺序为:DMPA用量>R值>TMP用量>中和度;当中和度为80%、TMP用量为1%、DMPA用量为4%、R值为1.10时,WPU胶膜的吸水率最小,为8.72%,耐水性最好。影响膜拉伸强度因素顺序为:DMPA用量>TMP用量>R值>中和度;当中和度为90%、TMP用量为3%、DMPA用量为5%、R值为1.20时,WPU胶膜的拉伸强度最高,为12.35 MPa。

A series of waterborne polyurethane(WPU)products were prepared by prepolymer dispersion method using isophorone diisocyanate(IPDI),propylene oxide(PPG),trimethylolpropane(TMP),dihydromethylic acid(DMPA)etc.The effects of neutralization degree,isocyanate index(R value),amount of hydrophilic agent and crosslinking agent on water resistance and mechanical properties of WPU were studied.The results showed that the tensile strength and water absorption increased with the increase of neutralization degree.With the increase of R value,the tensile strength increased and water absorption decreased.The tensile strength and water absorption of the film increased with the increase of the dosage of hydrophilic agent.With the increase of the dosage of cross-linking agent,the tensile strength of the film first increased and then decreased,and the water absorption first decreased and then increased.The results of orthogonal test show that the order of factors affecting WPU film water absorption is:DMPA dosage>R value>TMP dosage>neutralization degree.When the neutralization degree is 80%,the dosage of TMP is 1%,the dosage of DMPA is 4%,and the R value is 1.10,the WPU film has the lowest water absorption(8.72%)and the best water resistance.The order of factors affecting film tensile strength is:DMPA dosage>TMP dosage>R value>neutralization degree.When the neutralization degree is 90%,the dosage of TMP is 3%,the dosage of DMPA is 5%,and the R value is 1.20,the tensile strength of WPU film is the highest(12.35 MPa).