Modeling of Shape-Memory Recovery in Crosslinked Semicrystalline Polymers

Abstract:

In present work a new theoretical approach based on the modified three-element Eyring-Halsey mechanical model was used for the derivation of an equation, which describes the thermally-induced recovery of preloaded covalently crosslinked polymer. This approach takes into account the influence of crystallizable polymer network as well as of entangled slipped molecular chains. Modeling of the temperature dependences of shape-memory (SM) recovery strain and SM recovery rate detected at constant heating rate has been performed for three types of polyethylene with sufficiently different crystallinity and crosslink density at programming strain of 100%. The results of modeling agree well with the experimental data. The values of material parameters determined by fitting correspond satisfactorily to the estimations existing in literature. It is shown that the contribution of the entangled slipped molecules to the total stored SM strain increases with increasing degree of branching and crosslink density. The physical sense of main fitting parameters and their dependences on the material constants such as crystallinity are discussed.

• Periodical: Advances in Science and Technology (Volume 77)
• Pages: 319-324
• DOI: https://doi.org/10.4028/www.scientific.net/AST.77.319
• Online since: September 2012
• Authors: Igor Kolesov, Oleksandr Dolynchuk, Hans Joachim Radusch
• Keywords: Crosslink Density, Entanglement, Modeling, Polyethylene, Polymer Network, Shape Memory Effects (SME)

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