双羟基四配位硅改性水性聚氨酯乳液的制备及其性能

Research on di-hydroxy tetra coordinated water-borne polyurethane emulsion and its properties.

通过二步法制备了双羟基四配位硅（DHTS）改性水性聚氨酯，研究了n（NCO）／n（OH）、二羟甲基丙酸（DMPA）的含量、DHTS含量对水性聚氨酯乳液及成膜性能的影响。结果发现，确定n（NCO）／n（0H）在1．5～1．7之间，DMPA质量分数在5％左右，DHTS质量分数为2．6％时，制得的乳液外观呈蓝光半透明，稳定性高；涂膜耐热性高、吸水率低。与乙二胺作扩链剂时相比，用双羟基四配位硅作扩链剂合成出来的水性聚氨酯各方面性能均有所提高。

The water-borne polyurethane modified by the di-hydroxy tetra coordinated silicon was prepared by a two-step method.The influences of the ratio of NCO/OH,the content of DMPA and DHTS on the water-borne polyurethane emulsions and films were studied.It was found that the emulsion was blue,semi-transparent and stable,the particle size is small,and the thermal performance of the films was high,and water-absorption ratio was low when the ratio of NCO/OH was between 1.5～1.7,the content of DMPA was about 5%,the content of the di-hydroxy tetra coordinated silicon was less than 3%.The studies showed that the performances of the water borne polyurethane were improved with the di-hydroxy tetra coordinated silicon as chain extension agent compared to ethylene diamine.