Preparation,Characterization And Stabilization Of Emulsifier-free Homopolymer Cationic Latex Nanoparticles With Solvothermal Method

The cationic polymerization plays an important part in sewage treatment as flocculants. And it is widely used in gooey, water paint, fabric treating, sheet additive etc. Solvothermal method was combined with emulsifier-free emulsion polymerization to prepare PSt and PMMA nanoparticle latex with AIBA as initiator. The conversion was followed gravimertrically at different stage during reaction and nanoparticle was characterized with TEM, GPC, DTA and 1~H-NMR. The influence of temperature and content of solvent and initiator on the size and its dispersion of polymer particle, the optimal condition for preparation of the latex is discussed and explored. The test of stability including storage stability at normal or low temperature and stability to electrolyte is performed. The mechanism of emulsifier-free emulsion polymerization with solvothermal method was discussed .The result showed: 1. Through analyzing several kinds of factors affecting the emulsifier-free polymerization, reaction conditions and optimal proportioning had explored. 2. As temperature increasing, sizes of PSt nanoparticles decreased in the beginning and then increased and sizes of PMMA nanoparticles decreased continuously. The smallest size of nanoparticles is about 25nm for PSt samples, 30nm for PMMA samples; dispersion of molecule weigh is good. 3. The polymer was characterized by 1~HNMR,DTA,FT-IR. The results reveal that the content of syndiotactic polymer is high 4. The polymerization with solvothermal method are in accordance with mechanism of homogeneous nucleation and micelle nucleation, but different pressure for different temperature posed influence on the nucleation of nanoparticles.