羟乙基封端聚二甲基硅氧烷改性水性聚氨酯的合成

Synthesis of Hydroxyethyl-terminal Siloxanes Modified Waterborne Polyurethane

以聚四氢呋喃二醇、异佛尔酮二异氰酸酯(IPDI)和2,2-二羟甲基丙酸(DMPA)为主要原料,羟乙基封端聚二甲基硅氧烷(SHG)为改性剂,采用自乳化法合成了阴离子型有机硅改性水性聚氨酯(WPU)。考察了异氰酸酯基与羟基的量之比(R值)、DMPA用量及SHG用量对WPU及其胶膜性能的影响;通过荧光显微镜分析了改性前后WPU的结构。结果表明:当异氰酸酯基与羟基的量之比为1.2、DMPA质量分数为4%、SHG质量分数为2%时,改性WPU的黏度低、稳定性好;其胶膜的吸水率从17%下降至6%,接触角从30.3°提高至75.7°,耐热性提高;微观形态更规整。

Using polytetrahydrofuran glycol,isoflurane ketone diisocyanate（IPDI） and dimethylolpropionic acid（DMPA） as the main raw materials,a waterborne polyurethane（WPU） was synthesized by the self-emulsion method.The effect of processing conditions,such as the molar ratio of NCO/OH（R value）,the amount of the silicone and DMPA,on the quality of WPU emulsion and films,was also investigated.The structures of the product before and after adding silicone were characterized and compared by thermogravimetric analysis（TGA） and contact angle（CA） measurements.The results showed that a WPU emulsion with low viscosity,good stability,good water resistance was synthesized with the R value of 1.2,4% of DMPA,and 2% of hydroxyethyl-terminal siloxanes,The water absorption of the films was decreased from 17% to 6% and the contact angle was increased from 30.3°to 75.7°,while the thermal stability was improved.The morphology study of modified waterborne polyurethane showed an ordered structure.