ISSN:
1022-1352
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
Star-shaped polysiloxanes consisting of SiO2 cores and polydimethylsiloxane (PDMS) branches were successfully prepared by three methods using functionalized solvent-soluble silicates as a starting material. The first method involved the lithiation of a Si—OH functional silicate with butyllithium, followed by reaction with hexamethylcyclotrisiloxane (D3) and termination with a chlorosilane to afford a star polymer. In this case, the chain ends were substituted with vinyl or Si—OH functional groups. In the second method, a Si—Cl functional silicate was used as the source of the SiO2 core. A PDMS chain with a lithium silanolate terminal group was reacted with the Si—Cl functional silicate to provide a star polymer. In the third method, a PDMS chain with a diethylamino group at one chain end was reacted with the Si—OH functional silicate to form a star polymer. The Mark-Houwink constant a of the star polymer was 0,74, which is very close to that of a linear PDMS.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/macp.1994.021950608
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