无溶剂法合成高固含量水性聚氨酯

Waterborne polyurethane with high solid content synthesized by solvent-free

以混合二异氰酸酯[六亚甲基二异氰酸酯(HDI)/异佛尔酮二异氰酸酯(IPDI)]和聚己二酸丁二醇酯(PBA-2000)为基本原料、二羟甲基丁酸(DMBA)为亲水性单体[代替目前常用的二羟甲基丙酸(DMPA)]、三乙胺(TEA)为中和剂和乙二胺(EDA)为扩链剂,反应过程中不添加有机溶剂和催化剂,采用先乳化后扩链的预聚体分散法制备了固含量为50%左右的水性聚氨酯(WPU)。采用单因素试验法优选出制备WPU乳液的较佳工艺条件。结果表明:当R=n(-NCO)∶n(-OH)=1.88∶1、w(DMBA)=4.1%和n(EDA)∶n(-NCO)=0.37∶1时,WPU胶膜的强度(拉伸强度为23 MPa)和韧性(断裂伸长率为740%)俱佳。

With mixed diisocyanate[hexamethylene diisocyanate（HDI）/isophorone diisocyanate（IPDI）] and polybutylene glycol adipate（PBA-2000） as basic raw materials,dimethylolbutyric acid（DMBA） as a hydrophilic monomer[instead of common dimethylolpropionic acid（DMPA）],triethylamine（TEA） as a neutralizer and ethylenediamine（EDA） as a chain extender,a waterborne polyurethane（WPU） with about 50% solid content and without organic solvent and catalyst was prepared by emulsifing prepolymer before chain extension.The better process conditions of preparing WPU emulsion were preferred by single-factor experiment.The results showed that the strength（tensile strength by 23 MPa） and toughness（elongation at break by 740%） were all better for WPU film when mass fraction of DMBA was 4.1%,molar ratios of n（-NCO）∶n（-OH） and n（EDA）∶n（-NCO） were 1.88∶1 and 0.37∶1 respectively.