Sodium Bicarbonate and Citric Acid as Blowing Agents in Polymer Composites with Recycled Textiles: An Alternative to Azodicarbonamide

Resumo

The study evaluated the influence of sodium bicarbonate (SB) combined with citric acid (CA) as a blowing agent in polymeric compounds produced from recycled polymer and textile waste, comparing its performance with the conventional agent azodicarbonamide (ADC). The compounds were processed in a thermokinetic mixer (DRAISS Homogenizer), and the specimens were prepared by hydraulic press molding, using formulations with 5% and 10% of each blowing agent. Density measurements showed that the SB + CA combination, at a 10% concentration (FCSB10), achieved a 19.29% reduction in density compared to the non- expanded reference, surpassing the applications with azodicarbonamide. Although ADC was slightly more effective at lower concentrations (5%), the combined sodium bicarbonate and citric acid system demonstrated expansion without the need for initiators and without exposure to toxicological risks. The results indicate that this system may be a viable and sustainable alternative to ADC for producing expanded polymers, although adjustments in processing parameters and optimization are still required.