Polyhedral Oligomeric Silsesquioxane (POSS) Styrene Macromers
Abstract
Four polyhedral oligomeric silsesquioxane (POSS) macromers, R7Si8O12Styrene (R = isobutyl, cyclopentyl, cyclohexyl or phenyl) containing a single polymerizable styrene unit were synthesized from the POSS-trisilanols R7Si7O9(OH)3 in high yield and purity. The base-assisted reaction to produce these macromers appears to be general for POSS-trisilanols of this type. However, in some cases it may be necessary to control the rate at which base is present during reaction to prevent unwanted side reactions that decompose the trisilanol. Cyclohexyl, cyclopentyl and isobutyl substituted POSS-stryenes (at 30 weight % loadings) undergo free radical bulk polymerizations with styrene to produce polymers with an enhanced modulus above the glass transition temperature. The phenylPOSS-derivative is too insoluble in styrene to undergo this polymerization. The effect on modulus is more pronounced for the copolymers containing 30 weight % cycloalkylPOSS than that seen with isobutylPOSS. The effect of the group at the POSS cage on bulk polymer properties has been noted before and is presumed to arise from differences in polymer microstructure.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 20, 2001
- Accession Number
- ADA410398
Entities
People
- Brent D. Viers
- Shawn H. Phillips
- Timothy S. Haddad