St-BA-qBVPBr无乳阳离子共聚物乳胶粒研究

Stable functional cationic latices were synthetized by Emulsifier-free emulsion copolymerization of styrene (St) and butyl-acrylate (BA) with 1-butyl-4-vinylpyridinium bromide (qBVPBr) as functional comonomer using azo-bis (isobutyramidine hydrochloride) (AIBA) as initiator at 70±1℃. The distribution of cationic groups on the latex particle surface were determined by conductometric titration method. The influence of reaction temperature, the initiator amount, the comonomer amount and St/BA main monomer ratio on the monomer conversion, the particle size (Dp), number (Np), particle size distribution (PDI), and the surface properties of particles are investigated. The results indicate that Dp decrease with increasing reaction temperature and qBVPBr comonomer concents, the surface cationic group contents increase with increasing qBVPBr and AIBA contents; but with increasing AIBA concentrations, Dp decrease at first and then increase. In same recipe condition, the size of the particles by semicontinuous operations is bigger than one by batch operations and the particle are of obvious core/shell structure by semicontinuous operations.