Conductive polymer composites obtained from recycled poly(carbonate) and rubber blends for heating and sensing applications

Conductive polymer composites (CPCs) can be obtained by blending an insulating polymer matrix with conductive fillers. When the percolation of the dispersed particles is achieved, it is possible to obtain a sensible material for self‐regulated heating by the Joule effect. To fit the durable development concept only recycled materials have been used to design CPCs, i.e. poly(carbonate) (PC) pellets cut out from signal panels and crushed rubber particles from car tires. The conductive properties of the CPCs have been investigated to determine the percolation conditions and the conductivity level with regard to heating and sensing applications. High amplitude positive temperature coefficient (PTC) effects are obtained with [poly(carbonate)‐carbon black]80%/crushed rubber 20% CPC, i.e. (PC‐CB)80/CR20 m/m, over 120°C allowing self‐regulated heating. This result is noteworthy as there are no other results reported in the literature for amorphous thermoplastic matrices like PC. A positive synergy is found between carbon black (CB) and crushed rubber (CR) particles, which act as a PTC booster. Nevertheless, rubber particles already conductive must be doped by the addition of at least 5% v/v CB to achieve higher conductivities. The response amplitudes obtained with (PC‐CB)/CR CPC are large enough to allow sensing and have a good selectivity towards the studied vapors (toluene and dichloromethane); large CR particles are found to be more suitable for this application.