Preparation and performance of silicone-acrylic latex for exterior wall coating of dirt pickup resistance

A self-cross-linkable core-shell silicone-acrylic latex and coatings with excellent dirt pickup resistance were studied to solve the pollution problem for the exterior wall. This article focused on adding two silicon compounds with C C in the core and shell at the influence on latex and coating performance, respectively. First, the octamethylcyclotetrasiloxane (D 4 ) and tetramethyltetraethylcyclotetrasiloxaneand ( D 4 V ${\text{D}}_4^{\text{V}}$ ) were used to synthesize silicone copolymer (PVMS) by cationic ring-opening polymerization as the core. Next, in this silicone latex, butyl acrylate (BA), methyl methacrylate (MMA), methacrylic acid (MAA), and γ-methacryloxypropyltrimethoxysilane (A174) were copolymerized to form the silicone-acrylic latex (PVMS/ASI). Fourier Transform Infrared Spectrometers proved that PVMS was successfully grafted onto acrylic copolymer (ASI). The morphology of particles exhibited core-shell structure, which was clearly shown in TEM. Finally, a comprehensive study of the effect of D 4 V ${\text{D}}_4^{\text{V}}$ in the PVMS/ASI was conducted on the properties of such latexes, films, and coatings. It was found that the D 4 V ${\text{D}}_4^{\text{V}}$ content influenced quite significantly the properties of latexes and films (water absorption, contact angle, crosslinking degree) as well as the properties of coatings (dirt pickup resistance, water resistance, hardness, adhesion, water scrub resistance). Ultimately, it found that D 4 V ${\text{D}}_4^{\text{V}}$ had a positive effect on dirt pick-up. When D 4 V ${\text{D}}_4^{\text{V}}$ content was 23 wt% in PVMS/ASI, the coating had an excellent dirt pickup resistance with extremely low Δ R (2.65%).