Preparation And Application Of Modified Styrene-acrylic Latex And Water-based Coatings

With the continued strengthening of social environmental protection, low VOC waterborne coatings are paid attention gradually. Waterborne coatings has been widely used in architectural coatings, and in the field of wood coating and metal corrosion protective coatings are being developed. This paper prepared epoxy resin grafting styrene-acrylic latex and epoxy resin grafting styrene-acrylic-PU complex latexes aiming at developping novel waterborne thermal insulation and wood coatings respectively with high performance. This thesis is mainly consisted of three contents:(1) Epoxy-grafted styrene-acrylic latex (SA-g-EP):The attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), transmission electron microscopy (TEM), dynamic light scattering (DLS), thermogravimetric (TGA), differential scanning calorimetry (DSC), dynamic mechanical thermal technology (DMA) were used to characterize the (SA-g-EP) latex structure, size, and thermal decomposition stability and so on, the results indicated the molecular weight of the epoxy resin has a great influence on the grafting efficiency, E-20with a moderate molecular weight has the highest graft efficiency. The introduction of rigid epoxy resin can effectively improve the glass transition temperature of styrene-acrylic latex, wherein the crosslinking density of the SA-g-EP20latex film having excellent solvent resistance. Thermal mechanical properties of the epoxy-grafted styrene-acrylic latex film were strongly dependent on the molecular weight of the epoxy resin, and the SA-g-EP20latex film exhibits excellent thermal mechanical properties and thermal stability even though no cross-linking agent added.(2) Investigation of PU shell-styrene-acrylic grafted epoxy resin nuclear latex (PU-PSAEP) and its application in water-based wood coatings:the effects of PU content, epoxy resin content, enhancers, anti-wear agent, and functional additives on the performance of wood coatings were studied. The complax latexes were characterized by the impact stretching, DMA, FT-IR, and so on. The results indicated that the latex film made from15wt%PU,20wt%E-51has good tensile strength, water resistance, and hardness properties. The addition of3wt%nano-TiO2and8wt%wax emulsion can greatly improve the hardness, impact-resistant, scratch-resistant performance of the resulting water-based wood coating; when the ethylene glycol butyl ether was selected as the coalescent, the resulting coating has high hardness, high gloss and smooth appearance; RM-8W and RM-2020were used as thickening agent and flatting agent respectively, the obtained coating not only has excellent workability and storage stability.(3) SA-g-EP water-based thermal insulation coatings:the effects of adhesion materials, pigments and fillers, PVC on the performance of the water-based insulation coating were investigated. The coatings were characterized by the pencil scratch hardness tester, adhesion tester, hydraulic universal testing machine, microscopic infrared spectroscopy, thermal conductivity detector. The results indicated that the coating with60%PVC,12%hollow ceramic beads,2%infrared powder and using rutile-type titanium dioxide, has good heat insulation and mechanical propertoes.