羧酸型水性聚氨酯分散液的制备与性能研究

Study on preparation and performance of carboxylic-type waterborne polyurethane dispersion

以聚己二酸丁二醇酯二醇(PBA3000)、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,合成了羧酸型水性聚氨酯(WPU)。结果表明:一步法和两步法制成的WPU分散液及其胶膜特性相近,但一步法制备工艺更加简单;随着DMPA含量不断增加,预聚过程中体系黏度和分散液电导率上升,WPU胶膜的拉伸强度、硬度和吸水率增大,断裂伸长率和分散液粒径(<100 nm)减小;当n(PBA)∶n(DMPA)=2∶3时,R值越大,预聚过程中体系黏度越低,WPU胶膜的拉伸强度和硬度越大,而断裂伸长率和吸水率越小;当w(-COOH)=1.09%～2.37%时,WPU分散液的稳定性较好。

The carboxylic-type waterborne polyurethane（WPU） dispersions were made from polybutylene glycol adipate（PBA3000）,isophorone diisocyanate（IPDI） and dimethylol propionic acid（DMPA） as main raw materials.The results showed that the characteristics of WPU dispersions and films synthesized by one-step method were similar than those by two-step method,but one-step method was more convenient.The viscosity and conductivity of WPU dispersions,tensile strength,water absorption and hardness of WPU films were increased,but elongation at break of WPU films and particle diameter（100 nm） in dispersion were decreased when the mass fraction of-COOH group was increased.The tensile strength and hardness of WPU films were increased,but the viscosity of WPU dispersions,elongation at break and water absorption of WPU films were decreased when the R value was increased and the molar ratio of n（PBA）∶n（DMPA） was 2∶3.The WPU dispersions had well stability when mass fraction of-COOH group was between 1.09% and 2.37%.