Flow-induced crystallization of long chain aliphatic polyamides under a complex flow field: Inverted anisotropic structure and formation mechanism
Yes === The present work deals with the flow-induced multiple orientations and crystallization structure of polymer melts under a complex flow field. This complex flow field is characteristic of the consistent coupling of extensional “pulse” and closely followed shear flow in a narrow channel. Utili...
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ndltd-BRADFORD-oai-bradscholars.brad.ac.uk-10454-80412019-08-31T03:03:42Z Flow-induced crystallization of long chain aliphatic polyamides under a complex flow field: Inverted anisotropic structure and formation mechanism Gao, Y. Dong, X. Wang, L. Liu, G. Liu, X. Tuinea-Bobe, Cristina-Luminita Whiteside, Benjamin R. Coates, Philip D. Wang, D. Han, C.C. Flow-induced crystallisation Complex flow field Long chain aliphatic polyamides Yes The present work deals with the flow-induced multiple orientations and crystallization structure of polymer melts under a complex flow field. This complex flow field is characteristic of the consistent coupling of extensional “pulse” and closely followed shear flow in a narrow channel. Utilizing an ingenious combination of an advanced micro-injection device and long chain aliphatic polyamides (LCPA), the flow-induced crystallization morphology was well preserved for ex-situ synchrotron micro-focused wide angle X-ray scattering (μWAXS) as well as small angle X-ray scattering (SAXS). An inverted anisotropic crystallization structure was observed in two directions: perpendicular and parallel to the flow direction (FD). The novel anisotropic morphology implies the occurrence of wall slip and “global” fountain flow under the complex flow field. The mechanism of structure formation is elucidated in detail. The experimental results clearly indicate that the effect of extensional pulse on the polymer melt is restrained and further diminished due to either the transverse tumble of fountain flow or the rapid retraction of stretched high molecular weight tails. However, the residual shish-kebab structures in the core layer of the far-end of channel suggest that the effect of extensional pulse should be considered in the small-scaled geometries or under the high strain rate condition. 2016-04-01T09:27:57Z 2016-04-01T09:27:57Z 2015-09-02 2015-07-19 2015-07-22 Article Accepted Manuscript Gao Y, Dong X, Wang L et al (2015) Flow-induced crystallization of long chain aliphatic polyamides under a complex flow field: Inverted anisotropic structure and formation mechanism. Polymer. 73: 91-101. http://hdl.handle.net/10454/8041 en http://dx.doi.org/10.1016/j.polymer.2015.07.029 © 2015 Elsevier Ltd. Full-text reproduced in accordance with the publisher’s self-archiving policy. This manuscript version is made available under the CC-BY-NC-ND 4.0 license (http://creativecommons.org/licenses/by-nc-nd/4.0/) |
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en |
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Flow-induced crystallisation Complex flow field Long chain aliphatic polyamides |
spellingShingle |
Flow-induced crystallisation Complex flow field Long chain aliphatic polyamides Gao, Y. Dong, X. Wang, L. Liu, G. Liu, X. Tuinea-Bobe, Cristina-Luminita Whiteside, Benjamin R. Coates, Philip D. Wang, D. Han, C.C. Flow-induced crystallization of long chain aliphatic polyamides under a complex flow field: Inverted anisotropic structure and formation mechanism |
description |
Yes === The present work deals with the flow-induced multiple orientations and crystallization structure of polymer melts under a complex flow field. This complex flow field is characteristic of the consistent coupling of extensional “pulse” and closely followed shear flow in a narrow channel. Utilizing an ingenious combination of an advanced micro-injection device and long chain aliphatic polyamides (LCPA), the flow-induced crystallization morphology was well preserved for ex-situ synchrotron micro-focused wide angle X-ray scattering (μWAXS) as well as small angle X-ray scattering (SAXS). An inverted anisotropic crystallization structure was observed in two directions: perpendicular and parallel to the flow direction (FD). The novel anisotropic morphology implies the occurrence of wall slip and “global” fountain flow under the complex flow field. The mechanism of structure formation is elucidated in detail. The experimental results clearly indicate that the effect of extensional pulse on the polymer melt is restrained and further diminished due to either the transverse tumble of fountain flow or the rapid retraction of stretched high molecular weight tails. However, the residual shish-kebab structures in the core layer of the far-end of channel suggest that the effect of extensional pulse should be considered in the small-scaled geometries or under the high strain rate condition. |
author |
Gao, Y. Dong, X. Wang, L. Liu, G. Liu, X. Tuinea-Bobe, Cristina-Luminita Whiteside, Benjamin R. Coates, Philip D. Wang, D. Han, C.C. |
author_facet |
Gao, Y. Dong, X. Wang, L. Liu, G. Liu, X. Tuinea-Bobe, Cristina-Luminita Whiteside, Benjamin R. Coates, Philip D. Wang, D. Han, C.C. |
author_sort |
Gao, Y. |
title |
Flow-induced crystallization of long chain aliphatic polyamides under a complex flow field: Inverted anisotropic structure and formation mechanism |
title_short |
Flow-induced crystallization of long chain aliphatic polyamides under a complex flow field: Inverted anisotropic structure and formation mechanism |
title_full |
Flow-induced crystallization of long chain aliphatic polyamides under a complex flow field: Inverted anisotropic structure and formation mechanism |
title_fullStr |
Flow-induced crystallization of long chain aliphatic polyamides under a complex flow field: Inverted anisotropic structure and formation mechanism |
title_full_unstemmed |
Flow-induced crystallization of long chain aliphatic polyamides under a complex flow field: Inverted anisotropic structure and formation mechanism |
title_sort |
flow-induced crystallization of long chain aliphatic polyamides under a complex flow field: inverted anisotropic structure and formation mechanism |
publishDate |
2016 |
url |
http://hdl.handle.net/10454/8041 |
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