Abstract
There is a cationic group that makes sure waterborne polyurethane self-emulsify on the main or side chain of cationic waterborne polyurethane (CWPU), which brings excellent function to cationic polyurethane, simultaneously it reduces water resistance. In this research, the good stability of CWPU was prepared as well as the water resistance and softness of cationic waterborne polyurethane film was improved. Elasticity, extensibility, weight gain rate, contact angle, TG, and structure of polyurethane had been tested and evaluated. Also, emulsion stabilities of polyurethane were tested, including storage stability, high-temperature stability, freeze-thaw stability, electrolyte stability, acid stability, and dilution stability; In addition to that, particle size and its distribution were tested. The test showed that the emulsion stability of polyester polyurethane illustrated a good result, while the mechanical property, water resistance, and water repellency were poor. Moreover, mechanical property and water resistance of polyether polyurethane film were good, but high-temperature stability, acid and alkali resistant, and water repellency of emulsion showed poor. For the synthesis of polyurethane, mixed soft segments of polyester (PE2348) and polyether (ZC330) were used, when mass ratio of (PE2348) to (ZC330) is not less than 1, that helped to improve the emulsion stabilities, increased contact angle, decreased particle size. But the water-resistance of film weakened when mass ratios of PE2348 to ZC330 were increased and the mechanical property was poorer. TG showed that thermal stability became poor. The introduction of hydrophilic chain extender (N120) can reduce the water resistance and water repellency of polyurethane. When the mass fraction of N-methyl diethanolamine (MDEA) was about 6% to 7%, the smallest particle size was 61 nm, and the water repellency was larger. The increase of MDEA content would reduce the water-resistance of the film. Finally the effect of hydrophilic chain extender on waterborne polyurethane was studied.
Highlights
Polyurethanes characteristic functional group is the repeated urehtane (-NHCOO-) on the main chain of the polymer
Two cationic water-borne polymers were synthesized by using 58% of polyester diol (PE2348) and ZC330 of polyether triol as soft segments, 30% of IPDI of isophorone diisocyanate as hard segments, 6% of BDO of 1,4-butanediol and N220 of polyether diol as chain extenders, and 6% of MDEA of N-methyl diethanolamine as cationic chain extenders
After polyether polyurethane modified by hydroxyl alkyl polysiloxane (PPC), the emulsion has good acid and alkali stability, soft handle, good water resistance, and water repellency, but the emulsion and film become yellowing, and the mechanical properties become worse
Summary
Polyurethanes characteristic functional group is the repeated urehtane (-NHCOO-) on the main chain of the polymer. The research shows that the waterborne polyurethane emulsion modified by air drying vegetable oil is stable, with strong flexibility, high hardness, high adhesion, and strong water resistance. The novelty of this work is that the application of waterborne polyurethane in fabric finishing agent which contains cationic group in the main chain can improve the hand feel, wrinkle resistance, waterproof and moisture permeability of the fabric. Because of its positive charge, it has the good anti-static effect, can improve the antipilling phenomenon of fabric, and the fabric after polyurethane treatment, improve the adhesion between fibers, and enhance the washing resistance This strategy might provide a novel method in terms of synthesizing cationic waterborne polyurethane which is synthesized with soft and hard segments. Because the molecular structure of cationic waterborne polyurethane is mainly linear, and the molecular chain contains hydrophilic links and ionic groups on the side chain, which results in the poor heat resistance and water resistance. To improve the handle of cationic waterborne polyurethane and improve the mechanical properties of polyurethane film, a series of modified cationic waterborne polyurethane emulsions were prepared, and their properties and characterization were evaluated
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
