Low-temperature crystallization of poly(butylene succinate)

Low-temperature crystallization of poly(butylene succinate) (PBS) was investigated by conventional and temperature-modulated differential scanning calorimetry (DSC and TMDSC). After completion of primary crystallization, cooling of semicrystalline PBS to temperatures near or even below the glass transition temperature (T-g) leads to additional crystal growth. Such crystallization below T-g is identified by detection of frequency- and time-dependent reversing heat-capacity in non-isothermal and quasi-isothermal TMDSC analyses, respectively. Moreover, crystallization in the glassy state causes a shift of Tg to higher temperatures, thus affecting the properties of the amorphous phase. Low-temperature crystallization of amorphous PBS was re candy reported in the literature and linked to completion of enthalpy relaxation of the PBS glass. In the present study, low-temperature crystallization has been shown to occur also in semi crystalline PBS, with low temperature crystallization probably involving constrained amorphous segments already coupled with the crystals.