Multiple melting temperatures of poly(3,3‐diethylthietane)

Abstract

Abstract The melting behaviour of semicrystalline poly(3,3‐diethylthiethane) (PDET), was studied by differential scanning calorimetry (DSC), wide‐angle X‐ray scattering (WAXS), small‐angle light scattering (SALS), and thermooptical analysis (TOA). Two samples of number‐average molecular weights 6,0 · 10 4 and 1,8 · 10 5 and rather narrow molecular weight distributions (ratio of weight‐to number‐average molecular weights M̄ w /M̄ n = 1,3) were analyzed. When PDET is isothermally crystallized from the molten state in the range 275–333 K, the calorimetric curves show one or two melting endotherms, depending on crystallization temperature ( T c ) and heating rate. WAXS analysis shows conclusively that polymorphism is absent. It was shown that the melting behaviour of PDET is being dictated by processes of melting and recrystallization occurring during the experimental analysis.