| As the consciousness of global environmental protection has been enhanced gradually, environmental protection-coating becomes the main development direction of coating industry in the future. Water-borne wood coating takes water as dispersion medium and has many unique advantages such as non-toxic, no environmental pollution and harmless to the human body, which gains a lot popularities from the whole world. Acrylic resin which has an excellent comprehensive performance, is a commonly used resin preparation of waterborne wood coatings. And it has abundant monomer materials and simply synthesis process. However, compared with solvent resin, acrylic emulsion has many impacts need to be improved on chemical resistance and application. Therefore developing more and more high performance acrylic emulsions has become a research hotspot on the application of wood coating.1.In this paper, we mainly polymerized self-crosslinking acrylic emulsion through the Zn2+crosslinking with COOH taking styrene (St), butyl acrylate (BA), methyl acrylate (MA) as main monomers. We also have studied how the ratio of Zn2+ and COOH, initiator, glass transition temperature (Tg) and process etc affect the performance of the resin, which can obtain the best polymerization process and the optimal formula. It turns out that the optimal formula is glass transition temperature of 30℃,latex solid content of 40%,1.5% emulsifier of monomer mass, MAA is 12% of the total quality of monomer, initiator accounted for 0.3% of monomer mass,Zn2+/COOH ratio is 1:4. We found that both of these self-crosslinking acrylic emulsions are fast drying and excellent polishing and have good wetting and closeness when we apply them to wood primer. The Fourier transform infrared spectrometer (FTIR), the differential scanning calorimeter (DSC), the minimum film-forming temperature (MFFT) have been applied to characterize the emulsion polymer’s structure composition, glass transition temperature, the minimum film-forming temperature properties respectively.2.We also report a synthesis of self-crosslinking acrylic emulsion using MMA and BA as main monomers and A-171, DAAM-ADH and TMPTA as cross-linking monomers. We have adopted the design of core-shell structure emulsion in this synthesis. Core-shell ration, the polymerization process and cross-linking monomers have been observed to find out how they affect the coating film’s properties. The results showed that:the crosslinking system of A-171 and DAAM-ADH is good to block resistance and the chemical resistance has been improved significantly. Furthermore, the hardness of paint film was raised obviously using the DAAM-ADH system. The effect of TMPTA on block resistance and chemical resistance was the weakest. Finally through the best polymerization process delivered three cross-linking monomer into the resin system simultaneously, emulsion has low MFT and high Tg, good block resistance and chemical resistance, its hardness can reach 2H. FTIR, DSC, MFFT have been applied to characterize the composition of polymer, Tg, MFT etc.3.At last, we make up the paint using what we have synthesized, wood primer and wood clear-coating,painted two times of primer and one time wood clear-coating on the surface of dark walnut. The results show that this film has good decorative, chemical resistance and high hardness, which is a perfect waterborne wood coating with good comprehensive performance. Also it has a high value of market popularization. |
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