Mechanical and Materials Engineering, Department of

 

Department of Mechanical and Materials Engineering: Faculty Publications

Accessibility Remediation

If you are unable to use this item in its current form due to accessibility barriers, you may request remediation through our remediation request form.

ORCID IDs

Lirong Zheng: 0000-0001-6803-5048

Lucia Fernandez-Ballester: 0000-0001-6956-5104

Gerrit W. M. Peters: 0000-0001-7208-5128

Zhe Ma: 0000-0003-2458-4197

Document Type

Article

Date of this Version

5-2018

Citation

Published in Industrial & Engineering Chemistry Research 57 (2018), pp 6870−6877.

doi 10.1021/acs.iecr.8b00708

Comments

Copyright © 2018 American Chemical Society. Used by Permission.

Abstract

Flow-induced crystallization of α- and γ-phases was studied for a propylene/ethylene random copolymer with 3.4 mol % ethylene at two high temperatures of 132 and 142 °C by combining a pressure-driven slit flow device with real-time synchrotron wide-angle X-ray diffraction. At 132 °C, it was found that both α- and γ-phases were generated at shear stresses ranging from 0.091 to 0.110 MPa and that the γ-phase always appeared later than the α-phase. However, for 142 °C and the same stresses, only the α-phase formed. Only upon cooling the partially crystallized copolymer did the γ-phase emerge. The lack of γ-crystals obtained at 142 °C is opposite to the behavior reported for quiescent crystallization under pressure, for which increasing temperature results in more and even pure γ-crystals. In the current study, the absence of γ-phase at 142 °C is tentatively associated with lack of epitaxial nucleation on α-lamellae and to relatively low growth rate of γ-crystals.

Share

COinS