脂肪族水性聚氨酯胶膜的合成和性能研究

用傅里叶变换红外光谱以及凝胶渗透色谱对异氟尔酮二异氰酸酯（IPDI）型脂肪族水性聚氨酯胶膜进行了结构表征及分子量分布测试。在此基础上，详细研究了影响胶膜拉强度，断裂伸长率，24h吸水率等性能的关键因素。结果表明：用IPDI为原料合成的脂肪族中性聚氨酯胶膜的耐光性比用甲苯二异氰酸酯为原料合成的芳香族水性聚氨酯胶膜强；异氰酯基/羟基（NCO/OH，摩尔比）对胶膜的拉伸强度和断裂伸长率有显著影响。NCO/OH增大，胶膜的拉伸强度也增大；NCO/OH越大，胶膜越硬，断裂伸长率越小，亲水基团含量越大，胶膜24h吸水率也越大，胶膜的耐水性越低。

Synthesis and properties of aliphatic waterborne polyurethane

The structural characterization and molecular weight distribution measurement of aliphatic waterborne polyurethane film, a type of isophorone diisocyanate (IPDI) resin, was carried out by means of Fourier infrared spectrometer and gel permeation chromatograph. The key factors affecting tensile strength, elongation at break and the water absorption in 24 h of the films were discussed. The results show that the UV resistance of aliphatic waterborne polyurethane synthesized with IPDI as raw material is superior to that of aromatic waterborne polyurethane prepared from tolylene diisocyanate (TDI). The molar ratio of isocyano-to hydroxy (NCO/OH) has a significant influence on the tensile strength and elongation at break of the film. The tensile strength of the film rises as the NCO/OH ratio goes up; the higher the ratio, the harder the film and the lower the elongation at break. Furthermore, the higher the content percentage of COOH, the higher the water absorption while the lower the resistance to water of the film.