The Synthesis And Characterization Of The Waterborne Damping Coatings

The synthesis and characterization of core-shell latex particles hasbeen a greatly interesting topic with many major developments in the pastfew decades. Among the various structured core-shell latex particles, theparticles with multilayer structure are special, and have been reported tohave potential applications in biology, chemistry and physics. In thiswork, we designed a multilayer latex particle with controlled structures,each layer of the latex particles was composed by poly (styrene-butylacrylate). The preparation of the latex has been optimized and thefunction of different additives on the latex matrix were studied. The mainresearch works are as follows:1. We synthesised core-shell latexes with different layer numbers viastep-by-step emulsion polymerization, Divinylbenzene (K) was added asthe crosslinking agent but with different content. Dynamic laser scattering(DLS) characterization indicated such latexes have soundpolymerization stability. Dynamic mechanical analysis (DMA) showedthe amount and position of K have a great influence on the dampingproperties of the latexes. 2. A multilayer core-shell latex was synthesized but with gradientdecreasing glass temperatures (Tg) from the core (layer1) to the outmostshell (layer4). Combined atom force microscope (AFM) characterizationwith the film appearance formed by the particle emulsion, the resultsindicate such latexes have good film formation performance at ambienttemperature. The influence of the content of K added in the internal layers(i.e., layers1,2, and3), the total mass ratio and sequence between layers3and4, and the Tgof each layer on the damping properties of themultilayer latexes have been studied in details.3. Compared with the emulsion blends and simple core-shell latexes,the multilayer core-shell latex particles have the best damping properties.4. We prepared waterborne coatings by adding necessary additives tothe multilayer core-shell latex emulsion. Turbiscan LAB characterizationshowed that the type and amount of dispersant, anti-setting agent contentcan greatly influence the stability of the coating, DMA characterizationshowed that the filler content and the mixing speed can influence thedamping properties of the coating.