Effect og glass fiber on the viscosielastic and thermomechnical properties of poly(ether ether ketone)

The effect of glass fiber on the viscoelastic properties, thermal stability, permittivity and volume resistivity, as well as stress relation behavior of poly(ether ether ketone) (PEEK) was investigated using dynamic rheology, TGA, broadband dielectric spectroscopy and DMA over a wide range to temperature. The complex viscosity of PEEK filled glass fiber with 30 wt.% increases by one order of magnitude at 360 oC compared to the unfilled PEEK indicating that the glass fibers inhabited the polymer chains motion and reduced the free volume at high temperature in the melt. The viscosity and dynamic moduli (G' and G') of both PEEK and 30 wt.% glass fiber filled PEEK were not very sensitivity to the temperature variation (i,e.; the viscosity, G' and G' slightly decreased with increasing temperature). The angular frequency dependence of complex viscosity was found to be well described by Carreau-Yasuda model. It was also observed that the thermal stability of PEEK improved significantly by adding glass fibers. In addition, the relaxation modulus master curve at 200 oC reference temperature for glass filled PEEK is significantly higher than that of pure PEEK due to the excellent reinforcement effect of the glass fibers.