Full-field strain and temperature evolution of electroactive three-dimensional braided thermoplastic shape memory composites

Abstract

Three-dimensional (3D) braided shape memory polymer composites (SMPCs), combining braided structure with stimuli-responsive shape memory polymers, have broad potential for intelligent material design. We fabricated the 3D braided SMPCs with different braiding angles (15°, 25°, 35°) using a pre-impregnation method. The dynamic thermomechanical behaviors, three-point bending properties, recovery force, and shape memory behaviors were characterized. The full-field strain and temperature evolution during recovery have been recorded with 3D digital image correlation (DIC) technique and infrared camera. We found that the storage modulus, flexural modulus, and recovery force increase with the braiding angle decreased. The samples with the smaller braiding angle recover faster than that of the samples with bigger braiding angle. The shape recovery of the samples with 15° braiding angle occurred before being heated to the glass transition temperature. It is expected that the 3D braided SMPCs could be applied to smart structural design.