双组份水性聚氨酯的合成及其力学性能

Synthesis and mechanical properties of two-component waterborne polyurethane

用聚碳酸酯二元醇、六亚甲基二异氰酸酯和二羟甲基丙酸合成水性聚氨酯(WPU)乳液,对WPU乳液进行固化获得WPU膜,研究水性聚氨酯乳液中DMPA用量、中和度、OH/NCO摩尔比对水性聚氨酯膜力学性能的影响.结果表明:随着乳液中OH/NCO摩尔比增加,WPU膜的断裂强度、模量先增加后降低,在OH/NCO摩尔比为4∶1时有极大值,而伸长率在此时出现最小值;WPU膜的断裂强度、模量随DMPA用量的增加而增加,伸长率则减小;中和度为100%时WPU膜的断裂强度、模量达到极小值而伸长率出现极大值.

The waterborne polyurethane dispersion is synthesized by using polycarbonate diols,hexamethene diisocyanate（HDI）and dimethylol propionic acid（DMPA）,and the film is obtained through curing the dispersion.The effects of DMPA content,molar ratio of OH/NCO,and the degree of neutralization on the mechanical performance of the film are analyzed.The results show that the tensile strength and the initial modulus of the film increase first and then decrease with increasing of the molar ratio of OH/NCO.The maximum values of the tensile strength and the initial modulus,and the minimum values of elongation are located at 4∶1 of the molar ratio of OH/NCO;the tensile strength and the initial modulus increase with increasing the content of DMPA,but the elongation decreases;and the minimum values of the tensile strength and the initial modulus,and the maximum values of elongation are located at 100% of the degree of neutralization.