Competition between Heterogeneous Nucleation and Flow-Induced Crystallization of Polyamide 66 and Its Carbon Nanotube Composites.

Autor: Gohn AM; School of Engineering, Penn State Erie, 4701 College Drive, Erie, PA 16563, USA.; Interdisciplinary Center for Transfer-oriented Research in Natural Sciences, Martin Luther University Halle-Wittenberg, 06099, Halle/Saale, Germany., Zhang X; School of Engineering, Penn State Erie, 4701 College Drive, Erie, PA 16563, USA., McHale A; School of Engineering, Penn State Erie, 4701 College Drive, Erie, PA 16563, USA., Androsch R; Interdisciplinary Center for Transfer-oriented Research in Natural Sciences, Martin Luther University Halle-Wittenberg, 06099, Halle/Saale, Germany., Rhoades AM; School of Engineering, Penn State Erie, 4701 College Drive, Erie, PA 16563, USA.
Jazyk: angličtina
Zdroj: Macromolecular rapid communications [Macromol Rapid Commun] 2022 Dec; Vol. 43 (24), pp. e2200418. Date of Electronic Publication: 2022 Sep 08.
DOI: 10.1002/marc.202200418
Abstrakt: Both heterogeneous nucleation and flow-induced entropy reduction are the two well-known factors that accelerate polymer crystallization. However, the interplay of nucleation and flow-induced acceleration is still poorly understood. This work investigates the nucleating effect of carbon nanotubes (CNT) on both the quiescent and flow-induced crystallization kinetics of polyamide 66 (PA 66). The quiescent crystallization study indicates that CNT acts as a powerful nucleant, as suggested by the fact that the critical cooling rate to bypass crystallization and create the amorphous glassy state changes from 1000 K s -1 in PA 66 neat resin to a rate faster than 4000 K s -1 in the PA 66 nanocomposites. The flow-induced crystallization study indicates PA 66 onset crystallization time and morphology depend on the shear work introduced by rotational rheometry. A combined acceleration effect from CNT nucleants and flow-induced crystallization (FIC) persists when the CNT loading is under the saturation limit. However, if CNT loading meets the saturation limit, specific shear work shows no impact on the crystallization time, providing evidence that the role of the FIC acceleration effect no longer exists when nucleant acceleration dominates the crystallization of PA 66.
(© 2022 Wiley-VCH GmbH.)
Databáze: MEDLINE
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