Conductive polymer composites (CPC): influence of processing conditions, shear rate and temperature on electrical properties of poly(butylene terephthalate)/poly(amide12-b-tetramethyleneglycol) – carbon black blends

Conductive Polymer Composites (CPC) have been obtained by blending two immiscible polymers, poly(butylene terephthalate) (PBT) and poly(amide12-b-tetramethyleneglycol) (PEBAX) with carbon black (CB). The extrusion process allows to obtain anisotrope co-continuous structures of various morphologies depending on composition and experimental conditions. It is possible to enhance CPC conductivity with appropriate processing temperature (T_p) and screw speed (Ω), without changing the composition of the blend. The best results are obtained with Ω =5 rpm and T_p=260°C. PBT/PEBAX-CB resistivity evolution with T_p and Ω doesn't follow a linear law as expected from previous studies with poly(butylene terephthalate)/poly(ethylene)-CB and poly(butylene terephthalate)/poly(ethylene-co-ethyl acrylate)-CB systems. CB distribution has a more important impact on conductivity than polymers phase morphology. A good control of these parameters is essential to reproduce and optimize electrical properties.