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Direct synthesis and characterization of crosslinked polysiloxanes via anionic ring‐opening copolymerization with octaisobutyl‐polyhedral oligomeric silsesquioxane and octamethylcyclotetrasiloxane
Author(s) -
Li Hongying,
Zhang Junying,
Xu Riwei,
Yu Dingsheng
Publication year - 2006
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.24876
Subject(s) - octamethylcyclotetrasiloxane , silsesquioxane , copolymer , polymer chemistry , thermal stability , tetramethylammonium hydroxide , materials science , monomer , ring opening polymerization , hydrosilylation , glass transition , polybutadiene , hydroxide , potassium hydroxide , chemistry , catalysis , organic chemistry , polymer , composite material , nanotechnology
The crosslinked polysiloxanes were directly synthesized by anionic ring‐opening copolymerization of octaisobutyl‐polyhedral oligomeric silsesquioxane (POSS) as a multifunctional monomer with octamethylcyclotetrasiloxane (D 4 ) under base catalysts such as potassium hydroxide (KOH) or tetramethylammonium hydroxide (Me 4 NOH) siloxanolate. The mechanism of anionic ring‐opening copolymerization of octaisobutyl‐POSS and D 4 was discussed and the influences of the polar additive N , N ‐dimethylacetamide on gelation time at different temperatures were investigated. The results of gel content and swelling ratio, GPC, solid‐state 29 Si and 13 C NMR, FTIR, XRD show that octaisobutyl‐POSS is reacted and most of the product is crosslinked. The DSC and TG results indicate that the crosslinked polysiloxanes exhibit distinct glass transition temperatures ( T g ) and excellent thermal stability. Compared to that under KOH siloxanolate, the crosslinked polysiloxane synthesized with Me 4 NOH siloxanolate has better preferable thermal stability. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3848–3856, 2006