IADR Abstract Archives

Synthesis of Silicon Containing Monomers

Silicon-based-epoxy resins (siloranes) have been identified as key targets for use in cationically-cured composites. The monomers, bis[2-(3{7-oxabicyclo[4.1.0]heptyl})-ethyl]methylphenyl silane (PHEPSI)1 and 2,4,6,8-tetrakis(2-(7-oxabicyclo[4.1.0]heptan-3-yl)ethyl)-2,4,6,8-tetramethyl-1,3,5,7,2,4,6,8-tetraoxatetrasilocane (CYGEP),2 have been selected as our initial targets for such systems. Objectives: We will develop and optimize the synthesis of relevant silorane monomers for use in the healthcare field.

Methods: PHEPSI was synthesized by heating solution of 4-vinyl-1-cyclohexene-1,2-epoxide, methylphenylsilane, toluene, and Wilkinson's catalyst to 100°C for 24h. Column chromatography was used (silica gel; solvent, 90:10 hexane:ethyl acetate) to isolate PHEPSI. CYGEP was synthesized by refluxing solution of 4-vinyl-1-cyclohexene-1,2-epoxide, 2,4,6,8-tetramethylcyclotetrasiloxane, and toluene with a Dean-Stark trap for 2h, then cooled (5-9°C). After Lamoreaux's catalyst3 (1 drop) was added, resulting mixture was allowed to warm to room temperature (17h). Column chromatography (silica gel; solvent gradient,hexanes,90:10,80:20,ethyl acetate) was used to isolate CYGEP. Extent of reaction monitored by IR spectroscopy for disappearance of Si-H peaks for PHEPSI and CYGEP (2160 and 2100cm-1), respectively. Excess ethyl acetate removed via vacuum for both monomers. Results: Disappearance of Si-H peaks indicated completion of reactions. After purification, PHEPSI isolated in average yield (41%) as confirmed by 1H-and 13C-NMR spectroscopy. Addition of the catalyst to the resulting mixture below 5°C resulted in polymerization of solution to a gel, due to the freezing of toluene and temps above 9°C due to activation of the catalyst. After purification, CYGEP was isolated in average yield (61%) as confirmed by NMR spectroscopy. Conclusion: Two silorane monomers of interest were reproducably synthesized using modified procedures. This work was supported in part by NIH/NIDCR Grant R21 DE018336, NIH/NIDCR T32 (DE07294), and Missouri Life Science Research Board Grant (#13234-2007). 1. J.V. Crivello and D. Bi, J. Poly. Sci.: Part A: Poly Chem. 1994,32,683-697. 2. J.V. Crivello and J. L. Lee, J. Poly Sci.: Part A: Poly Chem. 1990,28,479-503.

3. H. F. Lamoreaux,U.S. Patent 3,220,972,1965.


Division: IADR/AADR/CADR General Session
Meeting: 2009 IADR/AADR/CADR General Session (Miami, Florida)
Location: Miami, Florida
Year: 2009
Final Presentation ID: 1018
Abstract Category|Abstract Category(s): Dental Materials 6: Polymer-based Materials-Chemistry and Composition
Authors
  • Miller, Bradley D.  ( University of Missouri -Kansas City, Kansas City, MO, USA )
  • Burneson, James A.  ( University of Missouri -Kansas City, Kansas City, N/A, USA )
  • Weiler, Rachel A.  ( University of Missouri -Kansas City, Kansas City, MO, USA )
  • Kilway, Kathleen V.  ( University of Missouri- Kansas City, Kansas City, MO, USA )
  • SESSION INFORMATION
    Poster Session
    Dental Polymers Poster I
    04/02/2009