APS March Meeting 2014
Volume 59, Number 1
Monday–Friday, March 3–7, 2014;
Denver, Colorado
Session W20: Focus Session: Membranes and Confinement
2:30 PM–5:30 PM,
Thursday, March 6, 2014
Room: 405
Sponsoring
Unit:
DPOLY
Chair: Pullickel Ajayan, Rice University
Abstract ID: BAPS.2014.MAR.W20.8
Abstract: W20.00008 : Crystallization and Phase Transitions in Polymer Nanolayered Systems under Confinement*
4:18 PM–4:54 PM
Preview Abstract
Abstract
Author:
Eric Baer
(Case Western Reserve University)
Forced assembly multiplication coextrusion has been reported as an advanced
technique to study crystallization and phase transitions for polymers under
confinement. This technique can readily produce continuous alternating
layered structures composed of two or three polymers [1, 2]. Multilayer
films fabricated by multiplication coextrusion consist of hundreds or
thousands of layers with individual layer thickness varying from 10
nanometers to several micrometers. The flexibility of this novel
multiplication coextrusion process, particularly at the nanoscale, enables
the study of confinement effects on polymer crystallization and phase
transitions.
We have discovered that the hierarchical morphology of many polymers can be
manipulated by confinement between rigid layers [2]. Spherulites are
flattened and lamella single crystals are oriented as the confining scale is
decreased towards the nano-level. Poly(ethylene oxide) (PEO),
poly($\varepsilon $-caprolactone) (PCL), syndiotactic polypropylene (sPP)
and poly(vinylidene fluoride) (PVDF) will be given as unique examples of
this phenomena [2, 3]. Depending on the crystallization temperature, two
major lamellae orientations ``in-plane'' or ``on-edge'' can be achieved,
which dramatically affect the multilayer film characteristics, such as film
barrier properties [2, 4].For some polymers such as high density
polyethylene (HDPE), in-plane lamellae orientation is difficult to achieve.
However, at the micro-scale, confined HDPE spherulites have tilted lamellae,
which also improve gas barrier properties.
Nanoscale multilayer films were also utilized to produce submicron size
polymer droplets by thermal breakup of the layers [4]. Phase transitional
behaviors during fractionated crystallization of these droplets will be
described as a powerful tool for the study of both heterogeneous and
homogeneous nucleation.
\\[4pt]
[1] M. Ponting, A. Hiltner and E. Baer, Macromolecular Symp, 294(2010), 19
-32.\\[0pt]
[2] J. l M. Carr, D.S. Langhe, M. T. Ponting, A. Hiltner, and E. Baer, J.
Mater. Res, 27(2012), 1326-1350.\\[0pt]
[3] J. M. Carr, M. Mackey, L. Flandinb, A. Hiltner and E. Baer, Polymer,
54(2013), 1679--1690.\\[0pt]
[4] D.S. Langhe, A. Hiltner and E. Baer, Polymer, 52(2011), 5879--5889.
*National Science Foundation under Grant No. DMR 0423914
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2014.MAR.W20.8