Preparation and Characterization of Waterborne Polyurethane Modified by 4-Maleimidophenol to Enhance the Mechanical and Thermal Properties

Abstract

A series of 4-maleimidophenol (4-HPM) modified waterborne polyurethane (MWPU) emulsions were successfully synthesized, using isophoronediisocyanate (IPDI), polycaprolactonediol (PCL, Mw = 1000), 1,4-butanediol (BDO), 2,2-dimethylolpropionic acid (DMPA), trimethylolpropane (TMP) and triethylamine (TEA) as raw material. The effects of 4-HPM content on the structure, morphology and physical properties of the MWPU were characterized by Fourier transform infrared spectroscopy, dynamic light scattering, transmission electron microscope, X-ray diffraction, thermogravimetric analysis, water absorption measurement, water contact angle measurement and tensile testing. The results revealed that with 4-HPM introduced into the WPUs backbones, the crystallinity, the hardness, tensile strength, water resistance and thermal stability of MWPU films were significantly augmented. Moreover, when the content of 4-HPM was 4.0 wt %, the tensile strength of the MWPU film was up to 46.4 MPa, improved about 134.19% (measurement error ±0.001) compared with WPU (19.8 MPa). When the content of 4-HPM was 6.0 wt %, the end decomposition temperature of the film was up to 489.6°C, improved 12.6% compared with WPU (434.8°C).