The Synthesis Of Reactive Surfactant And Its Application In Styrene-acrylic Emulsion

The nonionic reactive surfactant was prepared with R-MA and EOn-AA at 200℃,15mmHg for 5 h, R-MA was synthesized by maleic anhydride and fatty alcohol at 80℃for 4 h, EOn-AA was composed by poly(ethylene oxide) and crylic acid at 120℃for 4h.The chemical structure of the reactive surfactant was confirmed by FTIR and1H-NMR after purified. The emulsification,cloud point and the critical micelle concentrations was measured by emulsification test and surface tension. The experiment results show that the cloud point of C12MAPEG200AA is 44.3℃, its critical micelle concentration(CMC) is 1.47×10-4 mol.L-1 at 25℃, and the corresponding surface tensionγCMC is 31mN.m-1,which displays that C12MAPEG200AA possesses higher surface activity.The polymerization kinetics of C12MAPEG200AA in aqueous solution has been studied with KBrO3-KBr method. The effects of monomer concentrations initiator, concentrationsand temperature on kinetics of C12MAPEG200AA polymerization in aqueous solutions have been studied, the polymerization rate equation was determined, and the polymerization active energy was measured, at the same time the polymerization mechanism was discussed; The research indicated that the polymerization rate equation for C12MAPEG200AA is Rp=k[M]1.01[I]0.47, which displays that the chain termination reaction is the bimolecular mode, and the inititate process is independed on monomer concentration, and the apparent polymerization active energy is 62.34kJ/mol, so the rate of polymerization is slow and conversion rate is 73% within 3h. The reaction mechanism can explain the ploymerization process correctly.In comparision with sodium dodecyl sulfate in the emulsion copolymerization of styrene/butyi acrylate/ methyl methacrylate. The influence of the kinds and amounts of emulsifier and on properties of styrene-acrylic emulsion were researched. The water resistance, ion stability, freeze-thaw stability, storage stability and electrolyte stability were also investigated. The styrene-acrylic emulsion products were characterized by TEM, DSC and particle size analyze.The results showed that: when the amount of total surfactants are 4.5%, solid content of styrene-acrylic emulsion is 42.5%, the monomer conversion rate is 95.8%, gel fraction is 0.09% , the average partical size is 92nm,PDI is 0.09. The polymerization stability, storage stability, water resistance and single-dispersion of styrene-acrylic emulsion is better than which prepared by SDS. Investigated the relationship of monomer conversion, the latex particle size with the polymerization time by using a one-time feeding. Analysis the reasons of small particle size and narrow size distribution of reactive surfactant emulsion.