MDI-50型水性聚氨酯的合成及应用

Synthesis and Application of MDI-50 Based Waterborne Polyurethane

以2,4’-二苯基甲烷二异氰酸酯和4,4’-二苯基甲烷二异氰酸酯的混合物(MDI-50)为硬段,二羟甲基丙酸(DMPA)为水性扩链剂,聚碳酸酯二醇(PCDL)和聚丙二醇(PPG)为软段,合成了一系列的单组分水性聚氨酯乳液;研究了-NCO与-OH的摩尔比、DMPA的含量以及PCDL与PPG质量比对固化胶膜力学性能的影响,并将其涂覆在棉织物表面后,对涂层织物进行了扫描电镜观察、表面接触角测试。结果表明,随着-NCO与-OH的摩尔比、DMPA的含量以及PCDL与PPG质量比的增大,胶膜的拉伸强度都随之增大,断裂伸长率都随之减小;而涂覆有水性聚氨酯乳液的织物表面形貌平整,且接触角均大于90°,表现出良好的疏水性。

A series of single-component waterborne polyurethane were synthesized using 2,4′-diphenylmethane diisocyanate and 4,4′-diphenylmethane diisocyanate mixture(MDI-50)as its hard segments,dimethylol propionic acid(DMPA)as water-based chain extender,polycarbonate diol(PCDL)and polypropylene glycol(PPG)as its soft segments.The effect of the n(-NCO)/n(-OH)ratio,content of DMPA and PCDL/PPG mass ratio on the mechanical performance of the cured film was analyzed.It was also applied on cotton fabric surface,and the treated cotton fabrics were characterized through SEM and contact angle analysis.The results indicate that with increasing the NCO/OH mole ratio,content of DMPA and PCDL/PPG mass ratio,the tensile strength of the film increases and breaking elongation of the film decreases;the surface morphology of coated fabrics is smooth and the contact angle is greater than 90°,suggesting that the coated fabrics exhibit good hydrophobicity.