Thermal decomposition of technological polymer blends 1. Poly(aryl ether ether ketone) with a thermotropic liquid crystalline polymer

The thermal decomposition of blends of poly(aryl ether ether ketone), PEEK, with a thermotropic liquid crystalline polymer (LCP), VECTRA, was investig ated using thermogravimetric analysis under dynamic conditions. The activat ion energies were obtained using integral and differential methods. The the rmal analysis of the blends show that thermal stability is clearly affected with respect to the unblended materials, and it was also observed that the degradation process is accelerated by blending. In the case of VECTRA, the LCP is destabilized at high PEEK contents. The degrading polymer blends, a t various degrees of conversion, were examined by Fourier transform infrare d spectroscopy. The degradation mechanisms were analysed from the changes i n the vibrational spectra. Blending appears to modify only the rate of degr adation of the component polymers, the mechanisms remaining unchanged. (C) 1999 Elsevier Science Ltd. All rights reserved.