Publication: China Plastic, 2006, 20 (1):31-35

Abstract: The thermodynamic compatibility of PET/PTT blends was estimated based on the calculation of Gibbs free energy at various temperatures. It was found that the Gibbs free energy of the blends above 0。C in all proportions was negative, the Flory-Huggins parameter was 0.0174 at 0。C and increased with increasing temperature, which indicated that the blends were miscible. The glass transition temperatures and the cold crystallization temperature of that the blends determined by DSC were analyzed using Fox and Gordon-Taylor equations (with k-0.732), leading to the conclusion that PET/PTT blends are miscible in amorphous state. SEM also revealed homogeneous morphology on the surfaces of the quenched samples.