Characterization of monodisperse copolymer submicrospheres with branched structures and different glass-transition temperatures prepared by soap-free emulsion polymerization
✍ Scribed by Yi-Yu Liu; Ming-Yu Lo; Hui Chen
- Publisher
- John Wiley and Sons
- Year
- 2011
- Tongue
- English
- Weight
- 661 KB
- Volume
- 120
- Category
- Article
- ISSN
- 0021-8995
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✦ Synopsis
This study was focused on the synthesis of monodisperse poly(n-butyl methacrylate-co-methyl methacrylate) submicrospheres via soap-free emulsion polymerization and on their characterization. The glasstransition temperatures of poly(n-butyl methacrylate) and poly(methyl methacrylate) were approximately 25 and 110 C, respectively. Therefore, submicrospheres with different glass-transition temperatures could be obtained through the variation of the copolymer composition. In addition, relationships between the monomer feed concentration (M 0 ) and the Mark-Houwink constant (a) for the copolymer submicrospheres were proposed. The molecular weights of the copolymer submicrospheres decreased sharply with an increase in the weight fraction of n-butyl methacrylate. On the contrary, the particle diameter increased linearly from 277 to 335 nm with an increase in the weight fraction of n-butyl methacrylate. The a values decreased with an increase in M 0 , and this indicated that the branched structures of the copolymer submicrospheres were easily obtained when M 0 was higher than 0.11 g/mL of water. Consequently, the results of this study are expected to provide useful information for the synthesis of monodisperse copolymer submicrospheres by soap-free emulsion polymerization. V