Preparation and characterization of high-solid carboxylate/sulfonate waterborne polyurethane and its application in novel water-based superfine fiber synthetic material

With isophorone diisocyanate and polytetrahydrofuran as basic raw materials, dimethylolpropionic acid and 2,3-dihydroxypropanesulfonic acid triethylamine salt (DHPSTEA) as chain extension agents, trimethylolpropane as crosslinking agent, N, N-dimethylethanolamine as neutralizer, the high-solid carboxylate/sulfonate waterborne polyurethane (SC-HWPU) was synthesized. The effect of -COO-/-SO3- molar ratio on the properties of SC-HWPU was studied. Fourier transform infrared and x-ray photoelectron spectroscopy results demonstrated that the SC-HWPU molecular chain contained carboxylate and sulfonate groups. The results of thermogravimetric analysis, dynamic mechanical analysis, and mechanical properties of SC-HWPU film indicated that higher DHPSTEA content was favorable for the thermostability and mechanical properties when the total dosage of hydrophilic groups was invariable. When the mole ratio of -COO-/-SO3- is 8:2, the solid content of the prepared SC-HWPU3 emulsion can reach to 51.6%, which has excellent storage stability and alkali resistance stability. Subsequently, the application of SC-HWPU emulsion on the fixed-island type polyamide/polyethylene terephthalate copolymer superfine fiber non-woven fabric single-coating process was analyzed, and the water-base superfine fiber non-woven fabric was prepared. Scanning electron microscopy showed that there was still a large amount of SC-HWPU filled in the superfine fiber gap after alkali-decrement, indicating that SC-HWPU has excellent alkali resistance.