| In order to obtain aqueous polymers, the aqueous polyurethane was prepared without any organic solvents. Due to waterborne polyurethane film with the poor performance of water resistance and glossiness, and acrylate with disadvantage of low elasticity, wear resistance and temperature sensitive, aqueous polyurethane-acrylic hybrid emulsions interpenetrating polymer network were researched.A series of aqueous polyurethane dispersions with network structure and carbon-carbon double bonds were synthesized by adding polyether-tribasic alcohol(310) and partial blockaded with hydroxyethyl acrylate(HEA) without any organic solvents and metal catalysts. Then under the premise of without any emulsifiers, a series of waterborne polyurethane-acrylic hybrid emulsion interpenetrating network were prepared with the method of preemulsification semi-continuous. The structure and performance index of the hybrid latex were characterized by FTIR, GPC, particle size analysis and viscosity measurement. The hybrid latex films were measured by TGA, DSC, tensile tests and waterproof capacity. The effects of R value, DMBA content, soft segment components mass ratio, category and dosage of acrylic monomers, neutralization, EDA content, GMA content on hybrid emulsion synthesis and properties were investigated. Finally, the pilling resistance finishing agent,WPUA, was applied to cotton knitted fabric, polyester/wool and poly/cotton blended woven fabrics. The finishing agent content, curing temperature and time were optimized.The optimized preparing process of stable WPUA hybrid latexes with solid content of(50±2)%, water absorption of 4.8%, viscosity of 52.4m Pa.s, tensile strength of 8.6MPa and break elongation of 352.6% was indicated as follows: R value of 1.8 to2.0, DMBA content of 3.5% to 4.5%, 218/310 mass ratio of 8/2 or 7.5/2.5, BA/MMA mass ratio of 7/3, PA content of no higher than 40%, neutralization of 90%, EDA content of no higher than 75% and GMA content of 3%. The curing for cotton knitted fabric was operated at 100℃ for 3min using WPUA of 40g/L with the result that the pilling resistance was 4 levels higher and good stability under washing. The curing for blended woven fabrics of polyester/wool and polyester/cotton was operated at 120℃for 3min using WPUA of 80g/L with the result that the pilling resistance was respectively 4 and 3 levels higher and good stability under washing. The handle and white degree were the same with that of the original fabric.Scanning electron microscopy(SEM) showed that the yarns of fabrics finished by WPUA were neatly arranged while the original fabrics were tangly, which conformed that the former fabrics embodied good pilling resistance properties.Fourier-transform infrared spectrum analysis showed that WPU curve graph had the absorption peak of carbon-carbon double bonds. Using chemical analysis method,the actual content and the theoretical content of carbon-carbon double bonds were similar. Because of the carbon-carbon double bonds had been found in WPUA curve graph, it suggested that all acrylate monomers had reacted compeletly, and WPUA hybrid emulsion had been prepared successfully.GPC analysis indicated that number-average and weight-average molecular weight were respectively 1.4230×106g/mol and 1.4997×106g/mol, and dispersion coefficient was 1.054 in the WPUA hybrid emulsions. These suggested that the molecular weight distribution were relatively uniform.TGA analysis discovered that thermal stability of WPUA was better than WPU polymers.DSC analysis indicated that WPUA hybrid latexes had two glass transition temperature, namely soft-segment phase was-40.6℃and hard-segment phase was80.7℃. The micro-phase separation was obvious in the WPUA hybrid emulsions.Particle size distribution analysis showed that average particle was 169.3nm and dispersion coefficient was 0.096 in the WPUA hybrid latexes. The results mentioned above suggested good partical monodispersity, compatible phases between polyurethane and acrylate and satisfactory hybrid emulsion stability. |
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