الفهرس | Only 14 pages are availabe for public view |
Abstract This thesis aims to study relaxation processes in the Semicrystalline polymers. The thesis was carried out using three techniques; Differential Scanning Calorimetry (DSC), Temperature Modulated Scanning Calorimetry (TMDSC) and Dielectric Spectroscopy (DS). Using the TMDSC the results of the thesis revealed that: the Semicrystalline polymers are consists of three fractions; the rigid crystalline fraction (RCF), the rigid amorphous fraction (RAF) and the mobile amorphous fraction (MAF). The thesis revealed that the relaxation processes found in these polymers are of different kinds, these processes are the glass transition relaxation which occur at the glass transition temperature, the crystallization structure relaxation which occur at the crystallization temperature, the rigid amorphous fraction relaxation which occur above the glass transition temperature and the reversing melting relaxation which occur when the semicrystalline crystallized at high crystallization temperature. Beside these relaxations the dielectric relaxations where investigated using the DS. The Dielectric results were analyzed using the Havriliak Negami model. |