The Preparation Of Functional Composite Latex And Its Performance Research

Acrylic latex has excellent hydrolytic, light and oxidative stability, organosilicone resin with good hydrophobic breathable, low surface energy characteristics. The epoxy resin has excellent chemical resistance and adhesiveness. Polyurethane has good wear resistance and flexibility. In order to achieve a blend of all the advantages of different resin, three kinds of functional latexes were synthesized through the emulsion polymerization:organosilicone-acrylic latex(OSA), epoxy modified polyacrylate elasticity complex latex (EPA), polyurethane-polyacrylate(PUA) and polyurethane-epoxy-polyacrylat complex latex (PUEA).(1) Organosilicone-acrylic latex (OSA):The influence of emulsifier type and dosage on the size, size distribution, viscosity and morphology of the latexes was systematically investigated. The polymerization stability of latex and the water absorbance, thermal decomposition behavior and the mechanical properties of the latex films dependant on the organosilicone (KH-570) introduction on the latex shell were also studied. A reasonable mechanism for preparation silicon-acrylic complex latex was described. The results indicated that the thermal stability, water absorption and mechanical properties of the latex films were improved with the introduction of1%KH-570in shell compared with that of styrene-acrylic film. The particle size increases and its distribution broadens, while the viscosity decreases with increasing the ratio of non-ionic emulsifier to anionic emulsifiers, The particles had a regular spherical morphology. The tensile-strength and fracture elongation of the JS waterproof coating made from OSA latex comply with a standard of JS waterproof coating (JC/T894-2001).(2) Epoxy modified polyacrylate elasticity complex latex (EPA):The structure, size and property of the EPA latex were characterization by Attenuated total reflectance spectroscpic (ATR-FTIR), Transmission electron microscope (TEM), Dynamic Light Scattering (DLS), Thermal gravimetric analysis (TGA), and Differential scanning calorimetry (DSC). The results indicated that the glass transition temperature (Tg) of complex latex (EPA) decreased with adding10%content of epoxy (EP). Heat resistance, water resistance, alkali resistance and mechanical properties of the EPA films were increased obviously. The tensile-strength, fracture elongation and the stain resistance of the elastic coating made from EPA latex were1.01MPa,426%and26.7%respectively. (3) Polyurethane-polyacrylate(PUA) and polyurethane-epoxy-polyacrylat complex latex (PUEA):The polymerization parameters, the type of initiator and PU, temperature and amount of emulsifier were systematieally studied. The structure, size and property of the complex latex and latex films were characterization by ATR-FTIR, TEM, DLS, DSC and TGA. A reasonable mechanism for preparation complex latex was given. The effect of epoxy resin in PUEA latex film on the crosslinking degree, glass transition temperature (Tg) were discussed in detail. The water resistance, rigidity, solvent resistance of the crosslinked latex film were also studied. The results indicated that the optimum conditions to prepare stable latex are T=84℃, KPS used as initiator,1.3%emulsifier. The PU with double bonds is suitable to achieve stable PUA and PUEA composite latex and the crosslinked latex film with the IPN (interpenetrating network structure) structure has good water resistance and solvent resistance.