Synthesis and properties of cationic polyurethane-fluorinated acrylic hybrid latexes by emulsifier-free emulsion polymerization and the solvent-free method

A series of cationic polyurethane-fluorinated acrylic hybrid latex (PUFA) have been synthesized by solvent-free method. In the method, vinyl monomers acted as dilution agent and the polyurethane (PU) having quaternary ammonium groups acted as macromolecular emulsifier without using any other solvent and surfactant. The structure and properties of PUFA were characterized by Fourier transform infrared spectroscopy (FT-IR), F¹⁹ nuclear magnetic resonance (F¹⁹ NMR), particle size distribution (PSD) analysis, transmission electron microscopy (TEM), contact angle (CA), surface free energy analysis, scanning electron microscope (SEM) equipped with energy dispersive X-ray spectrometry (EDS), and thermogravimetric (TG) analysis. The FT-IR, F¹⁹ NMR, and EDS confirmed that the FA monomer had been introduced into the chain of the PUFA hybrid polymer. The PSD analysis indicated the particles of PUFA were smaller than corresponding pure PU dispersion and narrower in particle size distribution. The CA and surface free energy analysis proved the PUFA hybrid latex film with fluorine possessed higher contact angle and lower surface free energy in contrast with the film without fluorine. The FPUA films exhibited good surface property which could be enhanced at higher annealing temperature. The EDS of PUFA confirmed the fluorine enrichment on the surface of PUFA. TG analysis suggested the PUFA hybrid latex film had a better thermal stability than pure PU.