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Titolo:
Organic-inorganic hybrid materials XI. Characterization and degradation ofhydrogen-bonded acidic fluorinated poly(siloxane-amideimide-silica) hybrids
Autore:
Chang, TC; Wang, GP; Tsai, HC; Hong, YS; Chiu, YS;
Indirizzi:
NDU, Chung Cheng Inst Technol, Dept Appl Chem, Tahsi 335, Taoyuan, Taiwan NDU Tahsi Taoyuan Taiwan 335 , Dept Appl Chem, Tahsi 335, Taoyuan, Taiwan Chung Shan Inst Sci & Technol, Chem Syst Res Div, Taoyuan 325, Taiwan Chung Shan Inst Sci & Technol Taoyuan Taiwan 325 iv, Taoyuan 325, Taiwan
Titolo Testata:
POLYMER DEGRADATION AND STABILITY
fascicolo: 2, volume: 74, anno: 2001,
pagine: 229 - 237
SICI:
0141-3910(2001)74:2<229:OHMXCA>2.0.ZU;2-6
Fonte:
ISI
Lingua:
ENG
Soggetto:
SOL-GEL PROCESS; STRUCTURE PROPERTY BEHAVIOR; POLYIMIDE-SILICA HYBRIDS; COPOLYMERS; SENSORS; FILMS; ALKOXYSILANE; SEPARATION;
Keywords:
polyamideimide; silica; hybrids; relaxation; degradation;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
35
Recensione:
Indirizzi per estratti:
Indirizzo: Chang, TC NDU, Chung Cheng Inst Technol, Dept Appl Chem, Tahsi 335, Taoyuan, Taiwan NDU Tahsi Taoyuan Taiwan 335 l Chem, Tahsi 335, Taoyuan, Taiwan
Citazione:
T.C. Chang et al., "Organic-inorganic hybrid materials XI. Characterization and degradation ofhydrogen-bonded acidic fluorinated poly(siloxane-amideimide-silica) hybrids", POLYM DEGR, 74(2), 2001, pp. 229-237

Abstract

Hydrogen-bonded acidic fluorinated poly(siloxane-amideimide-silica) hybridmaterials (FPSAI-SiO2) were obtained using the sol-gel technique by polycondensation of tetramethoxysilane (TMOS) in diethoxysilane-terminated amic acid solution. IR, Si-29- and C-13-NMR spectroscopy and thermogravimetric analysis (TGA) were used to study hybrids containing various proportions of TMOS. The abundant Q(4) structures implied that in the absence of HCl the degree of condensation of TMOS was enhanced by hydrogen-bonded acidic fluorinated poly(siloxane amideimide). The microstructure and chain mobility of the hybrids were investigated by measurements of the spin-lattice relaxation time in the rotating frame (T-1 rho(H)) and the time constant for energy exchange between H-1 and Si-29 spin systems (T-SiH). The results suggested that the rate of polarization transfer in FPSAI-SiO2 hybrids was dependent onthe local motion. On the other hand, the spin-diffusion path length (L) inFPSAI-SiO2 hybrids was around 3.6 nm. The apparent activation energy (E-a)for degradation of the hybrids was studied by the van Krevelen method. TheEd values of the FPSAI-SiO2 hybrids in thermal degradation decreased with increasing silica content, whereas those for thermo-oxidative degradation were almost unchanged. (C) 2001 Elsevier Science Ltd. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 15/07/20 alle ore 14:15:03