Controlling porosity in bridged polysilsesquioxanes through elimination reactions
- Sandia National Labs., Albuquerque, NM (United States)
- Univ. of New Mexico, Albuquerque, NM (United States). Advanced Materials Lab.
The retro Diels-Alder reaction was used to modify porosity in hydrocarbon-bridged polysilsesquioxane gels. Microporous polysilsesquioxanes incorporating a thermally labile Diels-Alder adduct as the hydrocarbon bridging group were prepared by sol-gel polymerization of trans-2,3-bis(triethoxysilyl)norbornene. Upon heating the 2,3-norbornenylene-bridges polymers at temperatures above 250 C, the norbornenylene-bridging group underwent a retro Diels-Alder reaction losing cyclopentadiene and leaving behind a ethenylene-bridged polysilsesquioxane. Less than theoretical quantities of cyclopentadiene were volatilized indicating that some of the diene was either reacting with the silanol and olefinic rich material or undergoing oligomerization. Both scanning electron microscopy and nitrogen sorption porosimetry revealed net coarsening of pores (and reduction of surface area) in the materials with thermolysis.
- Research Organization:
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 244565
- Report Number(s):
- SAND-96-0010C; CONF-960401-37; ON: DE96010533; TRN: AHC29613%%40
- Resource Relation:
- Conference: Spring meeting of the Materials Research Society (MRS), San Francisco, CA (United States), 8-12 Apr 1996; Other Information: PBD: [1996]
- Country of Publication:
- United States
- Language:
- English
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