Carbon / Epoxy Resin Based Elastic Memory Composites

Elastic memory composites were processed from shape memory epoxy resins and carbon fabric reinforcements. Three different types of epoxies (diglycidyl ether of bisphenol-A, tris(4-glycidyloxy phenyl)methane, and epoxy novolac) were used as matrices. Developed composites were evaluated for flexural strength and analyzed by Dynamic Mechanical Thermal analysis. Of the three different epoxy systems with carbon: resin ratio of 50:50, the composite with diepoxy system exhibited maximum glass transition value of 119 °C, epoxy novalac system exhibited a low glass transition value of 54 °C and the tris epoxy system exhibited a glass transition of 100 °C respectively. The flexural strength and modulus of the composites were optimised at a concentration of 40 wt.%. The transition temperature also showed a maximum at around this composition. Bending test was adopted for the shape memory evaluation. All the developed composites exhibited more than 90% shape recovery. The diepoxy resin series of composites exhibited the maximum shape recovery of 97%. The shape recovery properties of the tris epoxy and epoxy novolac-based composites were inferior. For the diepoxy resin-based system, the shape recovery time was proportional to the resin content. The shape recovery of composite with 80% resin was demonstrated experimentally. The properties of the composites show that these systems have the required elastic memory characteristics for possible use in thermo-responsive self-deployable applications.