聚氨酯硬段含量变化对酪素/聚氨酯乳液及胶膜性能的影响

以异佛尔酮二异氰酸酯(IPDI)、聚四氢呋喃醚二醇(PTMEG1000)、二羟甲基丙酸(DMPA)、一缩二乙二醇(DEG)等为主要原料,固定酪素与聚氨酯的比例,通过改变聚氨酯硬段含量,制备出系列酪素/聚氨酯乳液(CWPU)。讨论了聚氨酯硬段含量的变化对CWPU状态、胶膜力学性能和热机械性能的影响。结果表明,随着聚氨酯硬段含量增加,聚氨酯分子之间、聚氨酯与酪素分子之间的氢键作用力增大,CWPU的粒径增大,分布变宽,乳液的粒径主要分布在100 nm左右;拉伸性能先增大后减小,硬段含量为64.61%时的拉伸强度达到41.75 MPa,断裂伸长率为344.75%。

Effect of Polyurethane Hard Segment Content on Casein/Polyurethane Emulsion and Film Properties

A series of polyurethane （PU） prepolymers were synthesized using polyethylene isophorone diisocya- nate （IPDI）, polytetramethylene ether glycol （FFMEG1000）, dihydroxy methyl propionic acid （DMPA） and shrinkage diethylene glycol （DEG） as raw materials. A series of casein/polyurethane （CWPU） emulsions were prepared with the proportion of casein and polyurethane fixed and changing the content of hard segment. The influ- ences of hard segment content on the state of emulsion, the film thermal and mechanical properties were discussed. The results showed that, with the hard segment content increasing, hydrogen bond force in casein/polyurethane in- creased, CWPU emulsion particle size increasing and having wider distribution. The particle size of emulsion was mainly distributed at around 100 nm. Tensile properties increased firstly and then decreased. The tensile strength arrived at 41.75 MPa, the elongation at break was 344. 75% when the hard segment content was 64.61%.