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The use of Polyaniline (PAni) as conductive filler in several kinds of non-conductive polymers, such as elastomers, has been extensively studied in the production of easily processable semiconductors. This work focuses on the use of a PAni/clay nanocomposite (PCN) – instead of pristine PAni – as conductive filler of styrene-butadiene rubber (SEBS) to produce a PCN/SEBS semiconducting elastomer. In order to accomplish this, a novel solvent-free and low-temperature press-processing technique was proposed and applied. It was also compared to the traditional rubber mechanical processing method. The preparation of PCN/SEBS was conducted by following a two-stage procedure: Pain in situ synthesis and mechanical mixing. PCN/SEBS was characterized by Raman spectroscopy, dynamic mechanical analysis (DMA) and scanning electron microscopy (SEM), the electrical properties were measured by means of the two-probe technique and electrochemical impedance spectroscopy (EIS). It was found that the traditional processing method led to a highly insulating material, while the proposed procedure results in semiconducting composites, showing electrical conductivity values up to 10−7 S cm−1. From the mechanical standpoint, this novel treatment results in composites with lower stiffness at low temperatures and similar elastic behavior at the transition region when compared to the material produced by the typical mixing chamber procedure. Although this method still needs to be improved since these materials show less homogeneity than their counterparts and they crumble at ∼100 °C, this work sets the foundation for an alternative processing method to obtain PAni-based semiconducting elastomers.

A series of poly(ortho-phenylenediamine-co-aniline)/iota-carrageenan biocomposites were synthesized via oxidative polymerization. Infrared spectroscopy revealed the ionic interaction between the sulfate groups in iota-carrageenan (i-CRG) and the quaternary amine groups in the copolymer, demonstrating that i-CRG exerts the function as the dopant. Cyclic voltammetry showed redox potentials around 35 mV, indicating that the i-CRG presence does not constrain electroactivity. Additionally, the biocomposites presented ionic and electrical conductivity (in the range of 10−5-10-3 S cm-1) determined respectively by electrochemical impedance spectroscopy and the four-point technique. Interestingly, it was observed by scanning electron microscopy that i-CRG played the role as a template since its presence, depending on the weight ratio respecting the copolymer, caused copolymer morphology modification. This set of properties is highly advantageous due to the combination of conduction mechanisms and electroactive behavior, which can be used in applications related to energy storage devices such as supercapacitors and chemical sensors.