Hybrid polymer latexes—acrylics‐polyurethane: II. mechanical properties

Abstract

AbstractPolyurethanes were prepared from reaction of isophorone diisocyanate (IPDI) with polypropylene glycol (PPG), with chain extension with butanediol (BDO). Their end groups are either methoxy, or methacrylic groups. These polyurethanes (PUs) are dissolved in mixtures of acrylic monomers (methylmethacrylate, MMA, and butylacrylate, BA). The solutions are sonicated to produce miniemulsion droplets, using sodium dodecyl sulfate (SDS) as surfactant, the PU being the hydrophobe. These miniemulsions were polymerized, with an oil‐soluble peroxide initiator. Those latexes with methoxy end groups in the PU are fully soluble, while those containing the acrylic end groups are almost fully crosslinked, but can easily form smooth films. The mechanical properties of these films were studied from their stress–strain curves, and compared with those films formed from the uncrosslinked hybrid latexes. Copyright © 2005 John Wiley & Sons, Ltd.