Investigation of a side-chain crystalline shape memory block copolymer and maximum bubble pressure rheology of organogels
Year: 2013
Type: article
Abstract: Shape memory polymers attracted many attentions recently for it is a smart material with applications in many fields.The objective of the first part of research was to investigate a new physically crosslinked shape memory triblock copolymer.Compared to the chemically crosslinked shape memory polymer an outstanding advantage of this shape memory material is that it can be very easily shaped and remolded by elevating the temperature to 140 o C, and after remolding the initial shape memory properties are totally recovered by eliminating the defects introduced by the previous deformation cycling.For this investigation, a poly(styrene-block-(methylacrylate-randomoctadecylacrylate)-block-styrene) (PS-b-(PMA-r-PODA)-b-PS) was synthesized by reversible addition fragmentation chain transfer polymerization.A three-dimensional, physically crosslinked network was generated by the self-assembly of the triblock copolymer, where the bridging of the midblocks across the glassy PS domains generates "permanent" network of the shape memory polymer.The side chain crystallization of the polyoctadecylacrylate side chains generates a second reversible network enabling shape memory properties.Shape memory tests by uniaxial deformation and recovery of molded dog-bone shape samples demonstrate that shape fixities above 96% and shape recoveries above 98% were obtained for extensional strains up to 300% when using rapid temperature jumps during strain fixing and recovery.Dynamic mechanical tests show the
Author: Pengzhan Fei
Institution: University of Akron
Language: English
Subfield: Polymers and Plastics
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2268217947