Formation and polymerization of cyclic disilsesquioxanes

American Chemical Society, Polymer Preprints, Division of Polymer Chemistry

Volumn 37, Issue 2, 1996, Pages 398-399

  Loy, Douglas A ^a   Carpenter, Joseph P ^a   Myers, Sharon A ^a   Assink, Roger A ^a   Small, James H ^b   Greaves, John ^b   Shea, Kenneth J ^b  

^a SANDIA NATIONAL LABORATORIES   (United States)

^b UNIVERSITY OF CALIFORNIA   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

CONDENSATION REACTIONS; GELATION; HYDROLYSIS; MASS SPECTROMETRY; MONOMERS; NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY; SOL-GELS; SYNTHESIS (CHEMICAL);

CYCLIC DISILSESQUIOXANES;

POLYMERIZATION;

EID: 0030204822     PISSN: 00323934     EISSN: None     Source Type: Conference Proceeding    
DOI: None     Document Type: Article

References (11)

1. Review on hydrocarbon-bridged polysilsesquioxanes: Loy, D. A.; Shea, K. J. Chem. Rev. 1995, 95, 1431-1442.
2. a) Small, J. H.; Shea, K. J.; Loy, D. A. J. Non Cryst. Solids 1993, 160, 234-46.
3. b) Oviatt, Jr., H. W.; Shea, K. J., Small, J. H. Chem. Mater. 1993, 5, 943-50.
4. c) Loy, D. A.; Jamison, G. M.; Baugher, B. M.; Russick, E. M.; Assink, R. A.; Prabakar, S.; Shea, K. J. J. Non Cryst. Solids 1995, 186, 44-53.
5. Sol-gel polymerizations were carried out at 0.4 M monomer concentration. It is significant to note that while bridged triethoxysilanes generally gel with a few hours at this concentration, tetraethoxysilane will not gel until the monomer concentration is above 1.8 M.
6. a) Englehardt, G.; Jancke, H.; Magi, M.; Pehk, T. ; Lippmaa, E. J. Organomet. Chem. 1971, 28, 293.
7. b) Burton, D. J.; Harris, R. K.; Dodgson, K.; Pellow, C. J.; Semlyen, J. A. Polymer Commun. 1983, 24, 278-281.
8. c) D. Seyferth; J. Robison, Macromolecules 1993, 26, 407-18.
9. Siloxane (Si-O-Si) bond angles were calculated to be 131.86° for 3 and 141.02° for 4 in comparison with a value of 145° for acyclic siloxanes. Calculations were performed using MM2 in Chemdraw 3D Plus, Cambridge Scientific Computing.
10. 3) siloxane bonds.
11. 29Si NMR signals due to hydrolyzed and cyclic siloxanes. See: Kelts, L. W. ; Effinger, N. J.; Melpolder, S. M. J. Non Cryst. Solids 1986, 83, 353-74.