Stresses in shape memory polymer-matrix nanocomposites for biomedical applications
Davor Balzar, G Stefanic, Kenneth Gall, Martin Dunn, Yiping Liu
We report on the residual stresses in amorphous shape memory polymers reinforced with SiC particles. After 50 % compression of the composite material at 25 ¿C, the SiC particles exhibit a compressive stress, which is almost completely released during heated recovery at 120 ¿C. The residual stresses in SiC hexagonal (6H) phase were estimated through the average change of the unit-cell volume. Lattice parameters of the starting SiC powder, as-prepared composites, deformed, and recovered composites were obtained by Rietveld refinement of diffraction patterns. The values of the internal residual stresses in the particles are compared to values based on micromechanics calculations.