Melt rheology of carbon nanofibres/nanotubes Filled poly(ether ether ketone) composites
Carbon nanofibres (CNFs) and carbon nanotubes (CNTs) are under intense investigation in material science owing to their potential for modifying the electrical conductivity, shear viscosity and other transport properties (thermal conductivity, diffusion, etc) of polymeric materials. From processing point of view, the effect of nanofillers on rheological properties is a very valuable knowledge to optimize the processing condition. This work aimed at examining the effects of nanofiller loading, aspect ratio, dispersion and molecular weight of the polymer matrix on the rheological and electrical behaviour of poly(ether ether ketone) (PEEK) composite melts. Both shear and elongational properties were investigated and correlated to microstructure formation, more explicitly, the network formation.
A range of multi-wall carbon nanotubes (MWNTs) and single-wall carbon nanotubes (SWNTs) reinforced high temperature semi-crystalline poly (ether ether ketone) were prepared by melt compounding processes. Addition of high apect ratio nanoparticles exhibits a dramatic effect on the flow properties of PEEK melt. Both viscosity and moduli show several order of increase in magnitude, particularly at low frequencies. A sharp transition from an electrically insulating to a conductive composite was observed between 1 and 1.5 wt.% for PEEK melts containing MWNTs. Rheotens measurements show that the melt strength increases significantly on addition of nanotubes, however the drawability decreases. Transient melt elongational measurements confirm that the elongational viscosity of PEEK significantly increased on addition of carbon nanotubes. However, this increment effect strongly depends on the degree of dispersion and distribution of nanotubes in the polymer matrix. The rheological effects discussed here are useful for understanding the processability of polymers undergoing foaming and fibre-spinning processes.Lesen Sie die deutsche Zusammenfassung auf Kunststoffe.de
Nanocomposites, carbon nanotubes, nanofibres, rheology, shear, elongation, conductivity, dispersion
Institute / chair: Fakultät für Angewandte Naturwissenschaften der Universität Bayreuth
Technical consultant for expert services: Prof. Dr.-Ing. Volker Altstädt (Betreuer), Prof. Dr. rer. nat. Helmut Münstedt
Publication year: 2009
Provider: Wissenschaftlicher Arbeitskreis Kunststofftechnik (WAK) / Kunststoffe.de
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