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Titolo:
INTERACTIONS OF HEXACHLORODIPHOSPHAZENIUM ION WITH ALCOHOL AND WITH SOME SILICON-OXYGEN REAGENTS AND THEIR ROLE IN THE CATALYSIS OF POLYCONDENSATION IN SILANOL-ALKOXYSILANE SYSTEMS
Autore:
CHOJNOWSKI J; CYPRYK M; FORTUNIAK W; KAZMIERSKI K; TAYLOR RG;
Indirizzi:
POLISH ACAD SCI,CTR MOL & MACROMOL STUDIES,SIENKIEWICZA 112 PL-90363 LODZ POLAND DOW CORNING CORP BARRY CF63 2Y1 S GLAM WALES
Titolo Testata:
Journal of organometallic chemistry
fascicolo: 2, volume: 526, anno: 1996,
pagine: 351 - 361
SICI:
0022-328X(1996)526:2<351:IOHIWA>2.0.ZU;2-7
Fonte:
ISI
Lingua:
ENG
Soggetto:
HEXACHLOROPHOSPHATE; CHLORIDE;
Keywords:
OLIGOPHOSPHAZENIUM IONS; CATALYSIS OF SILANOL CONDENSATION; CONDENSATION OF ALKOXYSILANE WITH SILANOL; REACTIONS OF HEXACHLORODIPHOSPHAZENIUM ION; SILICON; PHOSPHORUS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
29
Recensione:
Indirizzi per estratti:
Citazione:
J. Chojnowski et al., "INTERACTIONS OF HEXACHLORODIPHOSPHAZENIUM ION WITH ALCOHOL AND WITH SOME SILICON-OXYGEN REAGENTS AND THEIR ROLE IN THE CATALYSIS OF POLYCONDENSATION IN SILANOL-ALKOXYSILANE SYSTEMS", Journal of organometallic chemistry, 526(2), 1996, pp. 351-361

Abstract

Condensation reactions of trimethylethoxysilane (MOEt) and pentamethyldisiloxanol in n-heptane catalysed by hexachloro-1 lambda-diphosphaza-1-enium salts were studied. Although the substrate conversion vs. time dependences point to domination by heterofunctional condensation, the process is more complex, Homofunctional condensation as well as fastconsecutive hydrolysis and ethanolysis strongly contribute to the overall process. Results of kinetic studies point to inhibition of these component reactions by an excess of MOEt. Interactions of the hexachloro-1 lambda-diphosphaza-1-enium salts with MOEt, ethanol and silanol were studied by P-31 NMR. It was demonstrated that a fast substitution reaction of chloride by ethoxy group takes place when ethanol or ethoxysilane is introduced into solutions of hexachlorodiphosphazenium salts. This process is responsible for the decrease in condensation activity of the catalyst.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 03/07/20 alle ore 16:50:04