Synthesis And Application Of Polymer Emulsifiers Used In The Emulsion Polymerization Of Acrylate

Four polymer emulsifiers were synthesized and characterized in this thesis. These four polymer emulsifiers were P(BA/AA) (the coporymer of butyl acrylate (BA) and acrylic acid (AA)), P(St/AA) (the copolymer of styrene (St) and AA), and P(BA/St/AA) (the copolymer of BA, St and AA) which were synthesized in water, and P(BA/AA) which was synthesized in alcohol. As emulsifiers they were used in the emulsion polymerization of BA and methyl methacrylate (P(BA/MMA)). The factors which effected on the synthesis of these four copolymcrs and their properties such as the ratio of the monomers to the medium, pli, the kind of alkali, the weight ratio of monomers, the amount of initiator and the way of polymerization were discussed. The factors which effected on the properties of P(BA/MMA) emulsion and the water-resistance property of its coating such as the kind of emulsifiers, the amount of emulsifiers, the ratio of the emulsifiers when using the mixtures of P(BA/AA) and low molecule surfactant Tx-10 as emulsifiers , and the composition of polymer emulsifiers also were discussed.It was shown that P(St/AA) which was synthesized in water had no good property. When alkali was NaOH, pH was 6-8, the amount of initiator was 0.5 ).6)% weight of monomers, and the ratio of BA to AA was 35/65-45/55, PtBA'AA) which was synthesized in water had yood properties. Its lowest surface tension was 38mN/m,and the critical micelle concentration (CMC) of its aqueous solution was 1.0 X 10"2g/ml. When usinii this copolymer as emulsilier for emulsifying the monomer of acrylale, it luul good stability. When the ratio of AA was 65l'o and the ratio of BA was ilO-3i)p or when the ratio of AA was 60% and the ratio ot'B A was (15-35)%, P(RA7St/AA whieh was synthesi/ed in water had nogood solution property but when used as emulsifier for emulsifying the monomer of acrylate, it had good stability. When using alcohol as monomers' solvent, P(BA/AA) with good property could be synthesized. The lowest surface tension of its aqueous solution was 40mN/m, and its CMC was l.OX 10"2g/m' When using this copolymer as emulsifier for emulsifying the monomer of acrylate, it had good stability.P(BA/MMA) emulsion with good stability could be synthesized when using these copolymer (or P(BA/AA)/Tx-10 mixtures) as emulsifiers except using P(St/AA) as emulsifier and the average diameter of P(B A/MMA) latexes had narrow distributions. When the amount of emulsifiers was 3% weight of monomers, the coating of P(BA/MMA) emulsion had good water-resistance property. But P(BA/AA) which was synthesized in alcohol was the best in developing the water-resistance of the coating of P(BA/MMA) emulsion in these four emulsifiers, and the lowest water-absorbing amount of the coating was about 4%, which was much lower than that (25%) when using the mixtures of K12 and Tx-10 as emulsifiers.