Nanocomposites based on the cellulose extracted from the Amazon Peperomia pellucida and polyaniline derivatives: structural and thermal properties

Abstract

POMA/Cellulose and POEA/Cellulose nanocomposites were successfully synthesized based on interfacial polymerization over cellulose fibers extracted from the Amazon P. pellucida. The triclinic structure of poly(o-methoxyaniline) (POMA) and poly(o-ethoxyaniline) (POEA) was maintained after polymerization over cellulose fibers. However, possible chemical interactions between polymers and cellulose chains resulted in the increase of the average crystallite size, suggesting an oriented polymerization as well as the cellulose surface modification. The average crystallite size of POMA changed from (32 ± 2) A (for pure POMA) to (41 ± 2) A (for POMA in the nanocomposite form). The average crystallite size of POEA changed from (32 ± 2) A (for pure POEA) to (44 ± 2) A (for POEA in the nanocomposite form). Initially, the extracted cellulose presented average crystallite size of (29 ± 2) A, while the cellulose crystallites in the nanocomposites were found around (59 ± 2) A (POMA/Cellulose) and (92 ± 2) A (POEA/Cellulose). The morphology of POMA/Cellulose was significantly different from that observed in the pure as-synthesized POMA: globular vesicular shape was formed during the polymerization over the cellulose surface. In the POEA/Cellulose nanocomposite, the cellulose nanofibrils were also completely recovered by POEA consisting of well-defined nanometric spheres. These results were correlated with the thermal stability of the developed nanocomposites by Thermogravimetric Analysis (TG/dTG). Thus, the interfacial synthesis of POMA and POEA over a cellulose matrix was reported here, contributing to a better understanding of the thermal, structural and morphological properties of these resulting nanocomposites.