Preparation of polyvinylpyrrodione microspheres by dispersion polymerization |
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Authors: | Linfeng Zhai Tiejun Shi Hualin Wang |
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Institution: | (1) School of Chemical Technology, Hefei University of Technology, Hefei, 230009, China |
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Abstract: | The preparation of polyvinylpyrrolidone (PVP) microspheres in ethyl acetate by dispersion polymerization with N-vinylpyrrolidone (NVP) as initial monomer, poly(N-vinylpyrrolidone-co-vinyl acetate) (P (NVP-co-VAc)) as dispersant, and 2, 2′-azobisisobutyronitrile(AIBN) as initiator is reported. The influences of monomer concentration,
dispersant concentration and initiator concentration on the size of PVP microspheres as well as the monomer conversion were
studied. The structure and properties of PVP microspheres were analyzed. The results show that the prepared PVP microspheres
have a mean diameter of 3-4 μm. With an increase in NVP concentration, the size and the molecular weight of the PVP microspheres
as well as the monomer conversion all increase. With increasing P(NVP-co-VAc) concentrations, the PVP molecular weight and monomer conversion both increase while the size of the microspheres becomes
smaller. As the concentration of AIBN increases, the microsphere size and monomer conversion increase whereas the PVP molecular
weight decreases. The PVP prepared by dispersion polymerization has a crystal structure, and its molecular weight is lower
compared to that prepared by solution polymerization.
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Translated from Acta Polymerica Sinica, 2007, 11 (in Chinese) |
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Keywords: | polyvinylpyrrolidone microsphere dispersion polymerization preparation |
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