TITLE:
Thermophysical Characterization and Crystallization Kinetics of Semi-Crystalline Polymers
AUTHORS:
Matthieu Zinet, Zakariaa Refaa, M’hamed Boutaous, Shihe Xin, Patrick Bourgin
KEYWORDS:
Thermophysical Characterization; Heat Transfer; Crystallization Kinetics; Polymer; Multiphysical Modeling
JOURNAL NAME:
Journal of Modern Physics,
Vol.4 No.7B,
July
18,
2013
ABSTRACT: Final properties and behavior of polymer parts are known to be
directly linked to the thermomechanical history experienced during their processing.
Their quality depends on their structure, which is the result of the
interactions between the process and the polymers in terms of thermomechanical
kinetics. To study the actual behavior of a polymer during its transformation,
it is necessary to take into account all the thermal dependencies of their
thermophysical properties. In this paper, a complete experimental thermal
characterization of a semi-crystalline polymer is performed. Thermal conductivity
is measured using the hot wire method. The PVT diagram is obtained by means of an isobaric piston type dilatometer. Heat
capacity is characterized versus temperature by differential scanning
calorimetry (DSC). A modification of the Schneider rate crystallization
equations is proposed, allowing to identify in a simple way all the crystallization
kinetics parameters, using only DSC measurements. Finally, a multiphysical
coupled model is built in order to numerically simulate the cooling of a
polypropylene plate, as in the cooling stage of the injection molding process.
Calculated evolutions of temperature, crystallinity, pressure and specific
volume across the plate thickness are presented and commented.