Dielectric properties of chitosan and two ionic derivatives: Effect of counter anions

Ahmed Salama (1) , Fathia Mohamed (1) , Peter Hesemann (2)

1 National Research Center [Caire, Egypte]
2 ICGM - Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier

We report herein the dielectric properties response of two ionic chitosan derivatives. More specifically, we report here chitosan derivatives bearing guanidinium groups, prepared through the reaction between chitosan and cyanamide when scandium (III) triflate is present. The anionic counter ions of the guanidinium groups could be changed by working either in acetic acid or hydrochloric acid. In this way, two chitosan derivatives, namely N-guanidinium chitosan acetate (GChAc) and N-guanidinium chitosan chloride (GChCl), were produced. The materials were investigated by 13 C solid state NMR, FT-IR spectroscopy, SEM and TEM analysis and compared with the parent chitosan. The relaxation behavior of parent chitosan and new chitosan derivatives has been investigated by dielectric spectroscopy over wide temperature and frequency ranges, indicating that local motion is affected by counter ions. Due to these features, these materials are interesting candidates as high-power electrical materials for green technological applications.

Mots clés: Chitosan; Cationic derivative; Dielectric relaxation; Conductivity

Domaines: Matériaux

Ahmed Salama, Fathia Mohamed, Peter Hesemann. Dielectric properties of chitosan and two ionic derivatives: Effect of counter anions. Carbohydrate Polymers, 2022, 297, pp.120018. ⟨10.1016/j.carbpol.2022.120018⟩. ⟨hal-03795784⟩