Carbon Fillers for Actuation of Electroactive Thermoset Shape Memory Polyurethane Composites by Resistive Heating

Abstract

The shape memory polymer (SMP) is one type of smart material with shape memory effect. SMP’s recovery can be actuated by external energy, such as heat. However, traditional direct heating limits potential applications of the SMP device. Thus, focusing on stimuli-responsive SMPs enables researchers to develop more versatile devices with SMP composites. The electroactive SMP composites incorporated with conductive fillers such as carbon black and carbon nanotubes allow shape recovery actuation by electrical resistive heating. Until now, most developments in electroactive SMPs are based on the use of a thermoplastic matrix doped with conductive fillers. Only limited reports have been made of thermoset polymers as the matrix used to synthesize an electroactive SMP composite.

In this study, thermoset SMP composites with loading carbon black and carbon nanotube are made and characterized by evaluating thermomechanical behavior, measuring electrical resistivity and percolation threshold, coating with water-resistant membrane, and actuating the device with resistive heating. The electrical conductivity of thermoset SMP composites will be investigated so that a voltage-triggered or resistive-heat- triggered shape memory polymer for applications where a self-actuated polymer is necessary. The development of electroactive SMP composites makes this research advantageous for electrical resistive heating of device design in minimally invasive surgery application.