Melting behavior of poly(tetramethylene succinate) as studied by time-resolved small angle X-ray scattering

To elucidate the morphological origin of the multiple melting endothermic p eaks found in DSC scans of poly(tetramethylene succinate), a time-resolved small angle X-ray scattering study utilizing a synchrotron radiation source was conducted. The results suggested that low-temperature endothermic peak can be attributed to the melting of secondary lamellae inserted between th e primary lamella stacks, while the middle and high-temperature endothermic peaks were to the melting of primary lamellae. The middle one, however, wa s associated only with the original ones but the high endothermic peak was with both the original ones and lamellae reorganized through the recrystall ization process. A new small angle peak was observed in addition to the ori ginal peak during the late stage of melting process. The origin of the new peak was interpreted as a transient phenomenon resulted from the partial me lting of primary lamellae prior to the complete melting.