Seminarium ZTOC Rigid Amorphous Phase of PET and Implications for Lamellar Structure Peggy Cebe (Tufts University, USA) piątek, 4 czerwca 2010, godz. 10:15, sala S-3

Abstract Crystallization of polymers from the melt occurs from a highly entangled state. The crystals and amorphous chains remain in intimate contact throughout the crystallization process, leading to confinement and formation of the rigid amorphous fraction (RAF). Using modern thermo-analytical methods, such as quasi-isothermal temperature modulated calorimetry we investigate the vitrification and devitrification of RAF and its relationship to the crystalline fraction. We combine results from thermal analysis with small angle X-ray scattering and present a method to distinguish limiting cases of two different lamellar structural models incorporating RAF, by using PET, poly(ethylene terephthalate), as an example . Biography Peggy Cebe is a Professor of Physics at Tufts University in Medford, MA, USA. She received her Ph. D. in Physics from Cornell University in 1984 and then spent four years at the Caltech/NASA Jet Propulsion Laboratory, first as a postdoctoral research associate, and then as a member of the technical staff working in high performance polymers, such as poly(ether ether ketone), PEEK. She was Associate Professor in the Materials Science Department at MIT, before joining the faculty at Tufts University in 1995, in the Department of Physics and Astronomy. Her area of research concerns the thermal and structural properties of semicrystalline polymers, blends, and biopolymers. She performs high precision, high accuracy heat capacity measurements on these systems, combined with dielectric relaxation and X-ray scattering. She is a Fellow of American Physical Society and a Fellow of the North American Thermal Analysis Society.