POLY 120 |
| Polymers with alkoxysilane endgroups are useful building blocks for fabricating more complex polymer architectures or hybrid organic/inorganic materials. For example, functional polystyrene polymers have been used to prepare model star polymers and surface modified silica.1,2 The essential chemistry is the acid or base catalyzed hydrolysis (1) and condensation (2) of the alkoxysilane groups: (1) ≡Si-OR + H2O → ≡Si-OH + R-OH (2) ≡Si-OH + ≡Si-OH → ≡Si-O-Si≡ + H2O We have been investigating this chemistry in solution with the aim of preparing star polymers by a one-pot reaction. Initial experiments have examined optimizing the reaction conditions for hydrolysis and condensation of end-functionalized polyisoprene using various acid or base catalysts. The reactions are characterized by examining the products using size-exclusion chromatrography, NMR and FT-IR spectroscopy. In many cases the reactions proceed slowly and a significant amount of uncondensed polymer remains. In addition, conditions have been found where the polymer appears hydrolyzed, but no significant condensation occurs. Therefore, we have also begun experiments to examine if these hydrolyzed polymers are useful as either macro-initiators for polymerizing block copolymers or grafting agents for modifying silicon surfaces. 1. Long, T. E.; Kelts, L. W.; Turner, S. R.; Wesson, J. A.; Mourey, T.H. Macromolecules 1991, 24, 1431-1434. 2. Ohata, M.; Yamamoto, M.; Takano, A; Isono, Y. J. Appl. Polym. Sci. 1996, 59, 399-406. |
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Undergraduate Research in Polymer Science
6:00 PM-8:00 PM, Sunday, April 6, 2008 Morial Convention Center -- Hall A, Poster
Division of Polymer Chemistry |