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

Abstract

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.