Dirt-pickup resistant waterborne coatings based on acrylic/PDMS polymers blends

This article focuses on hydrophobic character of resin used in the coatings with the aim of enhancing dirt pick up resistance, and presents initially synthesizing of an acrylic (BA-St-AA) copolymer latex via emulsion polymerization and also, a polydimethylsiloxane (PDMS) homopolymer via cationic ring opening emulsion polymerization of octamethyl cyclotetrasiloxane (D4). The optimized latexes were then blended in different ratios (0/100 to 100/0) and the properties of the films were assessed using optical microscopy, Si-mapping EDX analysis, contact angle measurement and water uptake. It was found that 10-28 wt% PDMS in blends could provide continuous and clear films. The optimized latex blend film showed a drying time of 25 min, contact angle of 96o and water uptake of 27% after 6 days.

Keywords:

acrylic latex , PDMS latex , octamethylcyclotetrasiloxane , emulsion polymerization , film formation , acrylic/PDMS blends