| Two different morphologies of poly(4-vinyl pyridine) submicron particles were prepared by the self-stable precipitation polymerization, such as monodisperse microspheres and string-like particles. Effects of reaction media, reaction temperature, monomer concentrations, initiator concentrations and reaction time on the size and morphology of P4VP polymer particles prepared by the self-stable precipitation polymerization were investigated.A number of factors which affect the monodispersity of P4VP microspheres were studied. Influences of solubility parameter on the size and morphology of microspheres were analyzed by studying the solubility of reaction media. By exploring the reaction temperature, monomer concentration, initiator concentration and other factors, change rules of diameter of particles, size distribution and yield of P4VP monodisperse microspheres were researched. By polymerization experiment under different reaction time, this paper analyzes the growth process of monodisperse P4VP microspheres in single solvent medium, the mechanism of monodisperse microspheres was also investigated. And it's demonstrated that the curve of polymerization conversion versus time consistent with the feature of precipiation polymerization.The article also explores a series of factors which were the reason formed string-like P4VP particles. And the results of experiment indicate that the choice of mixed solvent is essential to the formation of string-like particles by self-stable precipitation polymerization. In based on obtaining string-like P4VP particles, the influences on serial morphology and size of P4VP particles were studied by controlling the monomer concentration, initiator concentration and reaction temperature. By polymerization experiment under different reaction time, this thesis discusses the growth process of serial type P4VP particles in mix solvent medium, the mechanism of string-like particles was also investigated. |
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