Crystallization and equilibrium melting behavior of PBT/PETG blends

Abstract

The results of studies of equilibrium melting point and crystallization behavior of PBT/PETG blends are reported for the first time. A single composition-dependent glass-transition temperature is observed in the DSC studies. The isothermal crystallization studies of the blends indicate retardation in crystallization rate as evidenced by the increase in crystallization half time. The retardation in crystallization rate has been attributed to the miscibility in the molten state and the hindrance to the diffusion of crystallizable units. This assumption is further supported by the composition dependence of the crystallization half time. A composition-dependent melting point depression has been observed which has been attributed to the possible thermodynamic and morphological effects. The interaction parameter calculated by analyzing equilibrium melting point depression shows composition-dependent negative values confirming the miscibility of the systems. These results are in good agreement with our earlier results on mechanical and dynamic mechanical properties of PBT/PETG blends. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 2439–2444, 1999