March 28, 2024
Ali Yadegari

Ali Yadegari

Academic Rank: Assistant professor
Address: Faculty of Petroleum, Gas and Petrochemical Engineering, Persian Gulf University, Bushehr, Iran
Degree: Ph.D in Polymer Engineering
Phone: 07731222634
Faculty: Faculty of Petroleum, Gas and Petrochemical Engineering

Research

Title Correlation of crystal alignment with interphase content in oriented high density polyethylene cast films
Type Article
Keywords
Journal CRYSTENGCOMM
DOI
Researchers Ali Yadegari (First researcher) ,

Abstract

The microstructure and crystalline morphology of high density polyethylene (HDPE) cast films prepared in a wide range of draw ratios (1.6 to 148.8) were investigated. The flow-induced orientation of crystalline and amorphous phases was characterized using Fourier transform infrared spectroscopy (FTIR). The results showed that the draw ratio has a crucial role on the orientation state of the cast films. Scanning electron microscopy (SEM) images also confirmed this influence. The crystallinity of the films was examined using both differential scanning calorimetry (DSC) and Raman spectroscopy. Moreover, considering a threephase structure (i.e. crystal, amorphous and interphase) for semi-crystalline polyethylene, Raman spectroscopy was also employed to estimate the amount of the so-called interphase in the HDPE cast films. As a result, the interphase content was found to decrease by increasing the applied draw ratio. The origin of this dependency was suggested to be due to a coil–stretch transition during elongation flow and the subsequent disentanglement. On the other hand, remarkable differences were observed in the CH2 bending vibration features of the Raman spectra of the cast films which were correlated with the applied draw ratios and with the calculated crystalline orientation functions.