Preparation and characterization of solid polymeric electrolytes based on hydroxypropylcellulose and hydroxyethlcellulose

Author(s)

Gilmara de Oliveira Machado

• Document type: Doctoral Thesis
• Press: São Carlos. , gráficos, ilustrações.
• Institution: Universidade de São Paulo (USP). Instituto de Física de São Carlos (IFSC/BT)
• Defense date: 2004-04-19

Examining board members

Agnieszka Joanna Pawlicka; Jose Pedro Donoso Gonzalez; Yoshio Kawano; Osvaldo Novais de Oliveira Junior; Roberto Manuel Torresi

• Advisor: Agnieszka Joanna Pawlicka
• Field of knowledge: Engineering - Materials and Metallurgical Engineering
• Indexed in: Banco de Dados Bibliográficos da USP-DEDALUS
• Location: Universidade de São Paulo. Biblioteca do Instituto de Física de São Carlos; IFSC-F; Te1587

Abstract

The present thesis reports the preparation and characterization of new types of solid polymeric electrolytes (SPE) based on cellulose derivatives such as hydroxypropylcellulose (HPC) and hydroxyethylcellulose (HEC), both commercial products. Aiming to reach this purpose both derivatives were subjected to modification processes, where HEC were physically modified by plasticization process with glycerol and HPC were submitted to chemical reactions. The latter ones were promoted by the oxidation of HPC hydroxyl groups and ketone groups and then subjected to grafting with diamine poly(propylene oxide) (Jeffamine), resulting in the imine bond network formation. Different concentrations of lithium salt were added to the plasticized and grafted samples, resulting in solid polymeric electrolytes, all in the film form. The characterization of these samples was performed by thermal analysis (DSC, TGA and DMTA), X-ray diffraction (XDR), scanning electron microscopy (SEM), ultraviolet/visible/near-infrared spectroscopy (UV/Vis/NIR) and, as most important, measured of ionic conductivity using the technique of electrochemical impedance spectroscopy (EIS). (AU)