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Titolo:
Molecular design of heat resistant polyimides having excellent processability and high glass transition temperature
Autore:
Yokota, R; Yamamoto, S; Yano, S; Sawaguchi, T; Hasegawa, M; Yamaguchi, H; Ozawa, H; Sato, R;
Indirizzi:
Inst Space & Astronaut Sci, Sagamihara, Kanagawa 229, Japan Inst Space & Astronaut Sci Sagamihara Kanagawa Japan 229 agawa 229, Japan Nihon Univ, Fac Sci & Engn, Dept Appl Chem, Chiyoda Ku, Tokyo 101, Japan Nihon Univ Tokyo Japan 101 Dept Appl Chem, Chiyoda Ku, Tokyo 101, Japan Toho Univ, Fac Sci, Dept Chem, Funabashi, Chiba 274, Japan Toho Univ Funabashi Chiba Japan 274 ept Chem, Funabashi, Chiba 274, Japan Ube Ind Ltd, R&D, Polymer Res Lab, Chiba 290, Japan Ube Ind Ltd Chiba Japan 290 Ltd, R&D, Polymer Res Lab, Chiba 290, Japan
Titolo Testata:
HIGH PERFORMANCE POLYMERS
fascicolo: 2, volume: 13, anno: 2001,
pagine: S61 - S72
SICI:
0954-0083(200106)13:2<S61:MDOHRP>2.0.ZU;2-B
Fonte:
ISI
Lingua:
ENG
Soggetto:
IMIDE OLIGOMERS; PENDENT;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
16
Recensione:
Indirizzi per estratti:
Indirizzo: Yokota, R Inst Space & Astronaut Sci, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229, Japan Inst Space & Astronaut Sci 3-1-1 Yoshinodai Sagamihara Kanagawa Japan 229
Citazione:
R. Yokota et al., "Molecular design of heat resistant polyimides having excellent processability and high glass transition temperature", HIGH PERF P, 13(2), 2001, pp. S61-S72

Abstract

The relationship between the imide structures-and morphology are discussedin order to develop heat resistant polyimides having excellent processability and toughness. Addition-type imide oligomers consisting of asymmetric 2,3,3 ' ,4 ' -biphenyltetracarboxylic dianhydride (a-BPDA) and 3,4 ' -oxydianiline (3,4 ' -ODA) and/or 4,4 ' -oxydianiline (4,4 ' -ODA) with 4-phenylethynyl phthalic anhydride (PEPA)were synthesized and characterized. The imide oligomers derived from 3,4 ' -ODA; 4,4 ' -ODA (50:50) comonomer having molecular weights of 5240 g mol(-1) (Oligo-10) and 1340 g mol(-1) (Oligo-1.5)showed good solubility in aprotic solvents such as DMAc and NMP, and were successfully cured at 370 degreesC for one hour. The thermal curing process, and thermal and rheological properties of the imide oligomers were investigated by FT-IR, differential scanning calorimetry, thermogravimetric analysis, and dynamic rheometry. It was observed that the melt flow dramaticallydecreased above the Tg for Oligo-1.5, resulting in a viscosity as low as 200 Poise at 300 degreesC. Whereas, a melt viscosity for Oligo-10 was 20 000Poise at 365 degreesC. The glass transition temperatures of these cured oligomers were 341 degreesC and 308 degreesC, respectively. In addition to the excellent melt property, the cured oligomers exhibited good thermo-oxidative stability. Furthermore, the cured imide oligomer consisting of a-BPDA and 4,4 ' -ODA with PEPA (Oligo-4.5) exhibited over 13% flexural elongation and a T-g of 343 degreesC. Their T-300 carbon fibre composites were also well consolidated demonstrating excellent processability and properties. It is concluded that amorphous, aromatic imide structures without any weak linkages.

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Documento generato il 04/04/20 alle ore 08:42:51