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Titolo:
Structure property relationships in linear and cross-linked poly(imidonorbornenes) prepared using ring opening metathesis polymerisation (ROMP)
Autore:
Hine, PJ; Leejarkpai, T; Khosravi, E; Duckett, RA; Feast, WJ;
Indirizzi:
Univ Durham, Interdisciplinary Res Ctr Polymer Sci & Technol, Durham DH1 3LE, England Univ Durham Durham England DH1 3LE ci & Technol, Durham DH1 3LE, England Univ Leeds, IRC Polymer Sci & Technol, Leeds LS2 9JT, W Yorkshire, EnglandUniv Leeds Leeds W Yorkshire England LS2 9JT S2 9JT, W Yorkshire, England
Titolo Testata:
POLYMER
fascicolo: 23, volume: 42, anno: 2001,
pagine: 9413 - 9422
SICI:
0032-3861(200110)42:23<9413:SPRILA>2.0.ZU;2-B
Fonte:
ISI
Lingua:
ENG
Soggetto:
ALKYL NORBORNENE DICARBOXYIMIDES; WELL-DEFINED INITIATORS; POLYMERIZATION; POLYMERS; CATALYST;
Keywords:
resin transfer moulding; tough well-defined networks; ROMP;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
36
Recensione:
Indirizzi per estratti:
Indirizzo: Feast, WJ Univ Durham, Interdisciplinary Res Ctr Polymer Sci & Technol, South Rd, Durham DH1 3LE, England Univ Durham South Rd Durham England DH1 3LE am DH1 3LE, England
Citazione:
P.J. Hine et al., "Structure property relationships in linear and cross-linked poly(imidonorbornenes) prepared using ring opening metathesis polymerisation (ROMP)", POLYMER, 42(23), 2001, pp. 9413-9422

Abstract

The production and properties of a new family of materials synthesised viaring opening metathesis polymerisation (ROMP) is described. The monomers offer potential alternatives to dicyclopentadiene (DCPD) for either reactioninjection moulding (RIM) or resin transfer moulding (RTM) use and provide new materials with an extended range of properties vis-a-vis poly(DCPD). improvements include lower monomer odour together with control of both the reaction rate and the crosslinking reaction. A series of monofunctional imidonorbornene monomers, with different N-alkyl side chains, were polymerised to give a range of linear polymers, and, by copolymerisation with difunctional. monomers with different N,N ' -alkylene spacer lengths, a range of crosslinked materials. Processing conditions were established which,gave over 95% conversion of the monomer for the linear materials, and over 95% gel fraction for the crosslinked materials. For the crosslinked materials, a valueof the monomer: initiator ratio was established which gave homogeneously cured materials. The glass transition temperature (T-g) of the linear polymers was found to depend on the length of the alkyl side chain, while a sub T-g beta relaxation was observed, the position of which was independent of the side chain length. For the crosslinked polymers, the molecular weight between crosslinks was found to be lower than expected at low percentage loading of the crosslinking unit, and this was attributed to the contribution of physical crosslinks. At higher percentage loading of the crosslinking unit, the molecular weight between crosslinks was higher than expected, suggesting that under these conditions not all the crosslinking units were fully bound into the network, i.e. bound at both ends. Mechanical properties of the various materials were measured using the three-point bend geometry. Of particular interest were the high values of yield strength and toughness ofthe crosslinked polymers, which are comparable to known 'high toughness' materials, such as polycarbonate. (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 28/09/20 alle ore 05:34:56