title: Physical Microfabrication of Shape-Memory Polymer Systems via Bicomponent Fiber Spinning.
abstract: As emerging technologies continue to require diverse materials capable of exhibiting tunable stimuli-responsiveness, shape-memory materials are of considerable significance because they can change size and/or shape in controllable fashion upon environmental stimulation. Of particular interest, shape-memory polymers (SMPs) have secured a central role in the ongoing development of relatively lightweight and remotely deployable devices that can be further designed with specific surface properties. In the case of thermally-activated SMPs, two functional chemical species must be present to provide (i) an elastic network capable of restoring the SMP to a previous strain state and (ii) switching elements that either lock-in or release a temporary strain at a well-defined thermal transition. While these species are chemically combined into a single macromolecule in most commercially available SMPs, this work establishes that, even though they are physically separated across one or more polymer/polymer interfaces, their shape-memory properties are retained in melt-spun bicomponent fibers. In the present study, we investigate the effects of fiber composition and cross-sectional geometry on both conventional and cold-draw shape memory, and report surprisingly high levels of strain fixity and recovery that generally improve upon strain cycling.
authors.affiliation: Fiber & Polymer Science Program, North Carolina State University, Raleigh, NC, 27695, USA.|Department of Materials Science & Engineering, North Carolina State University, Raleigh, NC, 27695, USA.
authors.forename: Syamal S
authors.initials: SS
authors.lastname: Tallury
authors.affiliation: Fiber & Polymer Science Program, North Carolina State University, Raleigh, NC, 27695, USA.|The Nonwovens Institute, North Carolina State University, Raleigh, NC, 27695, USA.
authors.forename: Behnam
authors.initials: B
authors.lastname: Pourdeyhimi
authors.affiliation: Fiber & Polymer Science Program, North Carolina State University, Raleigh, NC, 27695, USA.
authors.forename: Melissa A
authors.initials: MA
authors.lastname: Pasquinelli
authors.affiliation: Department of Materials Science & Engineering, North Carolina State University, Raleigh, NC, 27695, USA.|Department of Chemical & Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695, USA.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Spontak
keywords: bicomponent fibers; cold-draw; core-shell fibers; shape-memory polymers; thermoplastic elastomers