title: Isothermal crystallization kinetics of in situ photo and thermo aged poly(ethylene oxide) using photoDSC.
abstract: Isothermal crystallization of a high molecular weight PEO (Mw=4,000,000) has been investigated using photoDSC. Combining light irradiation, heating and DSC analysis, photoDSC demonstrates good capability to follow the in situ photo- and thermo-ageing of semi-crystalline polymers. Isothermal crystallization of PEO was performed at 55 degrees C. After ageing at different temperatures ranging from 0 to 90 degrees C and for various periods of time, the kinetics of this crystallization was found following the Avrami theory. Avrami exponent, n, was found between 0.9 and 1.4 evidencing a one-dimension growth process. It was also found that the isothermal crystallization rate (i.e. reciprocal crystallization half-time) was exposure time, ageing temperature and light intensity dependent which makes this kinetic parameter a good indicator of following and comparing the degradation of the semi-crystalline polymers.
authors.affiliation: Laboratoire de Photochimie Moléculaire et Macromoléculaire, UMR-CNRS 6505, TransChiMiC Université Blaise Pascal et Ecole Nationale Supérieure de Chimie de Clermont-Ferrand, 24 avenue des Landais, 63177, Aubière, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Fraïsse
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Nedelec
authors.forename: Jean Pierre E
authors.initials: JP
authors.lastname: Grolier
authors.forename: Mohamed
authors.initials: M
authors.lastname: Baba