Influence of Ionic Groups and Hydrogen Bonding Degree between Chain Segments on the Properties of Anionic Polyurethane

A series of polyurethanes, which have similar structures, bearing sulfonated soft segments (SSSPU), sulfonated hard segments (SHSPU) and carboxylated hard segments (CHSPU) are synthesized successfully by polymerization between polyester polyol, toluene diisocyanate (TDI) and diethylene glycol (DEG). Effects of hydrogen bonding degree between chain segments, the location and the type of ionic groups on properties of polyurethane (PU) film were studied via FT-IR, DSC, TG and mechanical property test. According to results, obvious micro-phase separation is observed in SSSPU film, as well as high mechanical property and heat resistance, resulting from strong hydrogen bond interaction between hard segments. On the contrary, the week hydrogen bond interaction in SHSPU film leads lower mechanical property and the formation of micro-phase mixing. Micro-phase mixing occured in CHSPU film is attributed to the hydrogen bond interaction forms not only between hard segments but also between hard segments and soft segments. In addition, hydrogen bond interaction and ion association of carboxylate also give CHSPU film the highest mechanical property.