Electro-active shape memory polymer nanocomposite from polyurethane matrix with carbon black fillers was synthesized and characterised for its electrical properties. The polyurethane matrix possesses high transition temperature, which enables it to be a candidate for high temperature applications. The carbon nanoparticle content was varied with conductivity measured at each instance, and a percolation threshold value of 6% was observed experimentally. The conductivity phenomenon was studied using Monte Carlo simulation approach on a pseudo random model of the system, developed using constrained optimization by linear approximations algorithm in visual C language platform. The probability of three dimensional network formations of carbon particles was evaluated for varying filler loading and percolation threshold of 6.2% was obtained from the model. The conductive networks formed have resulted in multiple electron paths, generating volumetric heating of the system while connected with a known power supply. This joule heating was used as stimuli for activating the shape memory behaviour by passage of electric current. High shape recovery efficiency (>95%) observed with faster recovery time (25 s), along with high transition temperature (85°) can help to qualify the system for space applications.

This paper presents a comprehensive structural orientation model to facilitate a hypothesis for the percolation threshold of nanotube-polyurethane systems, utilising Monte Carlo simulations. It considers a representative volume for nanotubes of diverse sizes and aspect ratios, uniformly dispersed at random positions and orientations. Continuous conductive networks formulated with the representative elements were identified for various filler contents, modelled and predicted percolation threshold of 0.19%. Experimental percolation threshold obtained was 0.21%, which determines the reliability of the model and furthermore, the model is broad and can, therefore, be extended to any nanocomposite, to predict the percolation threshold. The shape memory effect of the nanotube-polyurethane nanocomposite was evaluated for thermal and electrical stimuli, and the recovery efficiencies arrived to 95 and 98% respectively.