Modified shape memory epoxy resin composites by blending activity polyurethane

A series of modified shape-memory epoxy resin composites were prepared by blending activity polyurethane (APU). Fourier transform infrared spectroscopy (FTIR), tensile tests, scanning electron microscope (SEM), dynamic mechanical analysis (DMA), and fold-deploy shape memory tests were used to characterize the structure, mechanical, morphology, thermodynamics, and shape memory performance of these materials. FTIR results suggest that APU has been introduced into the resin matrix resin. Tensile test results show that the addition of appropriate APU can increase the elongation at break significantly, compared with neat epoxy. SEM results indicate that the fracture mechanism has changed from brittle to ductile, suggesting that the brittleness of the material has been overcome. DMA results show that modified materials have lower glass transition temperature (T_g) and lower cross-linking density for shape memory function. Furthermore, the fold-deploy shape memory tests prove that the materials possess excellent shape memory properties. They can be deformed into different shapes and recover their original shapes fully within 2 min at T_g, while they are hardly affected by ninefold-deploy cycles. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013