ISSN:
0022-3832
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
n-Amyltriethoxysilane and phenyltriethoxysilane were hydrolyzed in organic solvents in the presence of acidic or basic catalysts. The bulky substituents allow relatively large amounts of low-molecular-weight partial hydrolysis products to be isolated and stabilize the silanol functions present against further condensation. Cyclic ethoxypolysiloxanols in the molecular weight range 500-1000 are principal products of acid catalyzed hydrolysis. More extensive condensation occurs under alkaline conditions. Relatively high yields of low-polymeric silsesquioxanes (octamers and possibly hexamers) are then obtained. The major product obtained from phenyltriethoxysilane, when hydrolyzed in a ketone solvent with a quaternary base as catalyst, is an amorphous high polymer virtually free of functional groups. In inert solvents in the presence of traces of catalyst a very facile rearrangement occurs, giving the octamer (and possibly the hexamer) in very high yield.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1958.1202811603
Permalink
