No abstract

Two series of polyester and polyether waterborne polyurethanes (WPUs) modified with poly[(3,3,3‐trifluoropropyl)methylsiloxane] (PTFPMS) were synthesized by prepolymerization method and the effect of PTFPMS on surface and bulk properties were investigated by a variety of experimental methods. FTIR and DSC results showed that the polyester WPU has better compatibility between soft segments and hard segments than polyether WPU in bulk and the degree of phase separation increased in polyester WPU but decreased in polyether WPU with increasing PTFPMS. ARXPS analysis revealed the migration of PTFPMS to WPU surface and the migration ability of Si element was better than F element. AFM images demonstrated that the surface of WPU films became rougher as PTFPMS content increased. The enrichment of PTFPMS with low surface energy and roughened surface imparted good hydrophobicity and oleophobicity to WPU films and polyether WPU has better surface properties compared with polyester WPU. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46473.

Porous-coated fabrics used for synthetic leather were prepared by mechanical foaming method using blends of waterborne polyurethanes (WPUs) and polyacrylate (AC). The effect of AC on structure and properties of WPU/AC coated fabrics was investigated. Fourier transform infrared spectroscopy and differential scanning calorimetry results indicated that there is hydrogen bonding between WPU and AC and the compatibility of the blend system gets worse after AC/WPU ratio is higher than 30/70. Thermogravimetric analysis demonstrated that the thermal stability of porous coatings is improved with increasing AC. Scanning electron microscopy images showed that porous coatings have semi-open cellular structure with a great number of surface pores and window pores, imparting excellent air permeability and water vapor permeability to coated fabrics. On the basis of morphology analysis, the forming process of cell structure of WPU/AC coated fabrics was proposed. Performance tests showed that the overall performance of coated fabrics is best with AC/WPU ratio ranging from 15/85 to 30/70.