Hybrid polymer latexes: acrylics-polyurethane from miniemulsion polymerization: properties of hybrid latexes versus blends

Hybrid polymer latexes polyurethane/polyacrylic esters, are prepared through miniemulsion polymerization of polyurethane solutions in acrylic monomers. The polyurethanes are prepared by condensation of isophorone diisocyanate on polypropylene glycol (M-n = 1000) and butane diol as chain extender. The NCO chain ends being reacted with water (which act as a further chain extender producing some urea bonds). They are miniemulsified in a mixture of methylmethacrylate and butylacrylate monomers, and the miniemulsion are polymerized using benzoylperoxide as initiator. Films were obtained for different hybrid latexes of various compositions. Their mechanical properties have been compared with those of films from the basic components (polyurethane and acrylic latexes), as well as films from blends of these components. Some specific features of the surface of these films are also discussed from microscope images (TEM and AFM) as well as from contact angle measurements. (C) 2004 Elsevier Ltd. All rights reserved.