Self‐assembled polyurea macromer nanodispersion and resulting hybrid polyurea‐acrylic emulsions and films

Abstract

A polyurea macromer (PUM) was synthesized and dispersed in basic conditions to form self‐assembled nanoparticles (<20 nm dispersions, up to 30 wt % aq. soln.). These nanoparticles enabled surfactant‐free emulsion polymerization to form hybrid polyurea‐acrylic particles despite the absence of a measureable water‐soluble fraction. The Tg of the starting PUM material was a strong function of the PUM's extent of neutralization and hydration (varying between 100 °C and >175 °C) due to changes in hydrogen and ionic bonding. Two separate hybrid polyurea‐acrylic emulsion systems were prepared: one by direct polymerization of (meth)acrylic monomers in the presence of the nanodispersion and a second by a physical blend of PUM nanodispersion with an acrylic latex control. The direct polymerization method resulted in a hybrid emulsion particle size that developed by a mechanism resembling conventional emulsion polymerization and was unlike that described for seeded polyurethane dispersion systems. Film hardness was shown to increase with increasing coating thickness for the hybrid film prepared by direct polymerization. The resulting mechanical properties could be explained by applying mechanical models for a composite foam structure. These results were unprecedented for normal elastomer films. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1373–1388

Electroactive additives into polyurethanes for high corrosion resistance coatings for mild steel

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Design and Fabrication of Polyolefin–Acrylic Hybrid Latex Particles

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Investigation of segmental reorganization within amphiphilic block polymer nanoparticles derived from shell crosslinked micelle templates: Shell crosslinked knedel‐like inversion

“…In the 1990's, supramolecular assembly of amphiphilic block polymers in selective solvents, which thermodynamically favor one of the blocks, emerged as a general technique for the generation of micellar structures having morphological diversity . Over the past couple of decades, tuning the composition and architecture of the block polymer building blocks and incorporating environmentally responsive chemical functionalities have been shown to promote morphological switching and lead to enhanced behaviors and functions . The covalent stabilization of micelles and other supramolecular assemblies was also recognized as a powerful method, analogous to that utilized in biology, for the rapid and large‐scale preparation of intricate and stable nanostructured materials .…”