Abstract
AbstractThis work was aimed at studying supercritical carbon dioxide (scCO2)‐induced melting temperature depression and crystallization of a syndiotactic polypropylene (sPP). Under scCO2, the melting temperature of the sPP could be significantly reduced depending on the CO2 pressure. The scCO2‐induced crystallization of sPP was investigated using differential scanning calorimeter (DSC) and Fourier transform infrared spectroscopy. Two melting peaks were observed in DSC. The one at lower melting temperature referred to the melting of the sPP crystals induced by scCO2 in its amorphous phase. Its location was shifted to higher temperature, and its area increased with increasing scCO2 treatment time, temperature, and pressure. The melting peak at higher temperature corresponded to the melting of the sPP crystals that already existed before scCO2 treatment. Its location and area remained almost unaffected by the scCO2 treatment. The scCO2‐induced crystallization was related to scCO2‐promoted transformation of the mesophase form III of the sPP to the stable form I. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
