Study of Quenched Poly Ethylene Naphatalate (PEN) Using the Three-Phase Model by Differential Scanning Calorimetry (DSC)

Abstract

In order to optimize the use of some materials in electronic and microelectronic fields, the study of some of their properties is very important. Among these materials, we cite poly (ethylene naphtalate), PEN, which the description with a three-phase model is necessary to explain some of its dielectric behaviors, such as, for example, the relaxation peak. A thermal treatment by quenching the material in ice water at different temperatures has allowed us to obtain various partially crystalline poly ethylene naphtalate. DSC measurements have been carried out from 40 to 290 C in order to characterize the glass transition, melting point, and crystallinity of the obtained semicrystalline PEN. The results show the presence of a crystalline phase and a part of the amorphous phase that does not participate in glass transition, called the rigid amorphous phase. This later is more important in PEN than the one present in PET.

Contribution to the Study of the Enthalpy Relaxation of Polyesters by DSC Experiments

“…This result can be explained, in our opinion, by the increased thermal rigidity of PEN caused by its important aromaticity virtues. [7] Indeed, the molecular chains are stiffer than in PET and hence relax less, resulting in an endothermic peak less pronounced than the one appearing in the PET's relaxation. For a cooling rate higher than 5 C=min, the evolution of relaxation of PEN 15 cannot be observed.…”

“…The aim of this work is to study the structural relaxation (physical aging) of polyethylene naphthalate (PEN) by differential scanning calorimetry (DSC) and to compare the obtained results to those obtained within polyethylene terephtalte (PET) published by Doulache et al [4] Poly (ethylene therephthalate) PET and its concurrent poly (ethylene 2,6-naphtalate) PEN are two of the most widely used polymers in packaging applications because of their high performance in such areas as mechanical properties, transparency, and easy processing [7] . The excellent qualities of these materials are opening them up to a wide range of applications.…”

Contribution to the study of the amorphous phase of polyethylene terephtalate (PET) by the differential scanning calorimerty (DSC) experiments

“…Concerning the amorphous mobile phase rate χ am , it is calculated using (2) with the enthalpy jump value of the completely amorphous sample equal to 0.443 Jg -1 K -1 [6]. In an other case, the rate of the rigid amorphous phase χ ar is estimated using (3).…”

“…For the rate of the rigid amorphous phase χ ar , it can be deduced from the model of three phases [6], using the following equation:…”

“…Plastics belonging to this class of materials can crystallize by cooling or after annealing at temperatures above their glass transition temperature [2][3][4][5][6]. However, the structure of these systems is more complex than single crystal particles.…”