Thermal and dynamic mechanical properties of polycarbonate/poly(p-t-butylphenol formaldehyde) blend films

The blend system of bisphenol-A polycarbonate (PC) with poly (p-t-butylphenol formaldehyde) (PTBF) has been investigated for differential thermal and dynamic mechanical behaviour. The blends cast by the common solution technique exhibited a composition-dependent glass-transition temperature as measured by differential thermal and dynamic mechanical analysis (DTA and DMA), indicating miscibility. The blends exhibit a composition-dependent morphology dominated by low level PC crystallization with increasing PTBF content. Wide-angle X-ray diffraction and Fourier transform i.r. spectroscopy provide evidence that PC crystallizes in the blends. The blend systems exhibits composition-dependent mechanical behaviour, discussed in terms of the variations in shape and magnitude of tanδ, E′ and E″ curves of the dynamic mechanical spectra. It is concluded that PTBF blends with PC to form a miscible single amorphous phase for all compositions.