The problem of food agro-industry residues represents a growing concern in our society, therefore its use as a raw material to obtain biopolymers of technological interest is an attractive alternative. The objective of this work was to assess the viability of utilizing cardol, derived from cashew nut shell liquid, in the production of a biopolymer composite by combining it with cassava starch. The biopolymer composite was prepared by thermochemical method using different cardol concentrations and varying the synthesis pH. The results allowed us to demonstrate the formation of cardol/starch biopolymeric films. The infrared spectra showed possible interactions by hydrogen bonds between the cardol and the glucose units of the starch. The impedance behavior showed a similar conduction mechanism in all cases, allowing the establishment of a single equivalent circuit. The electrochemical parameters showed that the presence of cardol and the lower pH increased the values of the electrical resistance and the double layer capacitance in the biopolymers. In addition, the values of the CPE/Rre system, related to the electractivity, were not affected by the pH, but by the presence of cardol. The biodegradability tests showed a complete decomposition of the biopolymer composite films in three stages in a period of 17 to 19 days. It could be concluded that it is possible to use the cardol extracted from the cashew nut shell liquid to elaborate a biopolymer composite with electrochemical properties when combined with cassava starch. The electrical properties of the biopolymer can be modulated by varying the synthesis pH and the amount of cardol used. The composite cardol/starch biopolymer could be used as a biopolymeric solid electrolyte in the manufacture of batteries, capacitors, etc

The United Nations have established Responsible Consumption and Production as one Sustainable Development Goal. This goal demands strategies for the efficient utilization of natural resources, agro-industrial waste, and the development of eco-friendly materials. Thus, the objective of this work was to develop bio-based films synthesized with anacardic acid (AA) extracted from the Cashew Nut Shell Liquid (CNSL) and starch extracted from cassava. Biopolymer films were synthesized at different pH values with various concentrations of AA. The biopolymer films prepared at basic pH presented higher tensile strength and the addition of AA also contributed to increasing the tensile strength. Infrared spectroscopy allowed the establishment of possible hydrogen bond interaction between AA and the polymeric chain of cassava starch, which could contribute to its higher tensile strength. The degradation rate was not affected by the synthesis pH, but by the presence of AA. Cyclic voltammetry allowed evidence of the electroactivity of glucose and AA in the composite biopolymer films. The results allowed it to conclude that it was possible to obtain a composite biopolymer from thermochemical synthesis with AA and cassava starch. The presence of AA can improve tensile strength, decrease the rate of biodegradability, and improve the electroactivity of the films.