Rheological behaviour and molecular structure of long-chain branched semifluorinated thermoplastics

Autor: Harald Kaspar, Helmut Münstedt, Daniel Möller
Rok vydání: 2009
Předmět:
Zdroj: Rheologica Acta. 48:509-516
ISSN: 1435-1528
0035-4511
DOI: 10.1007/s00397-008-0342-8
Popis: The long-chain branched thermoplastic tetrafluoroethylene–hexafluoropropylene–vinylidenefluoride terpolymers (LCB THV) investigated in this paper are new polymers with a unique combination of properties like a high stability against aging or weathering and a very good chemical resistance. But not much is known about the rheological behaviour of the LCB THV, yet. In this paper, non-linear rheological properties like shear thinning and strain hardening are studied. Two different types of the THV with different contents of comonomers and, therefore, different melting points are examined. The THV with the higher melting point is insoluble. The other with the lower melting temperature is soluble and, therefore, was characterised by size exclusion chromatography coupled with light scattering with respect to its molecular structure. The results of the rheological measurements show a pronounced shear-thinning and strain-hardening behaviour for the long-chain branched materials. Both properties are of great importance for processing operations governed by shear and elongational flows.
Databáze: OpenAIRE
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