Thermo-mechanical behavior of epoxy shape memory polymer foams

Published

Journal Article

Shape memory polymer foams have significant potential in biomedical and aerospace applications, but their thermo-mechanical behavior under relevant deformation conditions is not well understood. In this paper we examine the thermo-mechanical behavior of epoxy shape memory polymer foams with an average relative density of nearly 20%. These foams are deformed under conditions of varying stress, strain, and temperature. The glass transition temperature of the foam was measured to be approximately 90 °C and compression and tensile tests were performed at temperatures ranging from 25 to 125 °C. Various shape recovery tests were used to measure recovery properties under different thermo-mechanical conditions. Tensile strain to failure was measured as a function of temperature to probe the maximum recovery limits of the foam in both temperature and strain space. Compression tests were performed to examine compressibility of the material as a function of temperature; these foams can be compacted as much as 80% and still experience full strain recovery over multiple cycles. Furthermore, both tensile strain to failure tests and cyclic compression recovery tests revealed that deforming at a temperature of 80 °C maximizes macroscopic strain recovery. Deformation temperatures above or below this optimal value lead to lower failure strains in tension and the accumulation of non-recoverable strains in cyclic compression. Micro-computed tomography (micro-CT) scans of the foam at various compressed states were used to understand foam deformation mechanisms. The micro-CT studies revealed the bending, buckling, and collapse of cells with increasing compression, consistent with results from published numerical simulations. © IOP Publishing Ltd.

Full Text

Duke Authors

Cited Authors

  • Di Prima, MA; Lesniewski, M; Gall, K; McDowell, DL; Sanderson, T; Campbell, D

Published Date

  • December 1, 2007

Published In

Volume / Issue

  • 16 / 6

Start / End Page

  • 2330 - 2340

Electronic International Standard Serial Number (EISSN)

  • 1361-665X

International Standard Serial Number (ISSN)

  • 0964-1726

Digital Object Identifier (DOI)

  • 10.1088/0964-1726/16/6/037

Citation Source

  • Scopus