不同内交联水性聚氨酯的合成与性能

Synthesis and Properties of Different Internal Crosslinking Waterborne Polyurethane

分别以三羟甲基丙烷(TMP)、二乙烯三胺(DETA)和N-(β-氨乙基)-γ-氨丙基三甲氧基硅烷(KH-792)为内交联单体合成水性聚氨酯(WPU),探讨不同交联单体及用量对WPU乳液性能、胶膜力学性能和热性能的影响。研究发现随着内交联单体的增加,WPU粒径先较小后增大,当TMP的量超过16%后,WPU乳液稳定性开始下降,而采用后扩链方式的DETA和KH-792则对乳液的稳定性影响要小。WPU胶膜力学性能数据表明,随着TMP增加,胶膜模量升高,但是伸长率和断裂应力下降;而随着DETA增加,胶膜模量升高,断裂应力下降,伸长率和拉伸强度先升高后降低;随着KH-792的增加,胶膜模量升高,断裂应力、伸长率和拉伸强度都是先升高后降低。DSC分析表明交联后WPU胶膜的微相分离程度都有所增加,TMP交联方式WPU微相分离程度最高。

Waterborne polyurethane(WPU)was synthesized by using trimethylolpropane(TMP),diethylenetriamine(DETA),and N-(β-Aminoethyl)-γ-Aminopropyl trimethoxysilane(KH-792)as internal crosslinking monomer.The effects of different internal crosslinking monomers and their content on the properties of WPU dispersion,mechanical properties and thermal properties of the films were investigated.It was found that particle size of WPU first decrease and then increase with the increase of internal crosslinking monomer.When the amount of TMP exceeded 16%,the stability of WPU began to decline,while DETA and KH-792,which use as post chain extender,had little effect on the stability.The mechanical data of WPU film shows that with the increase of TMP,the modulus of WPU film increases,but the elongation and breaking stress decrease;As DETA increases,the modulus of WPU film increases,the breaking stress decreases,and the elongation and tensile strength first increase and then decrease;With the increase of KH-792,the modulus of WPU film increases,and the fracture stress,elongation,and tensile strength first increase and then decrease.The DSC analysis shows that the microphase separation degree of WPU film increases after crosslinking,and the TMP crosslinking method has the highest microphase separation degree of WPU film.