Thermally stable and highly porous separator based on cellulose acetate by glycolic acid

Porous membrane is used as various materials in general and it is highlighted as a battery separator. In this study, a membrane is prepared using cellulose acetate (CA), which has better thermal stability than a commercial separator such as polypropylene (PP) or polyethylene (PE). In addition, glycolic acid is used as an additive for a low-cost process. The hydration effect of glycolic acid induces a plasticizing effect on cellulose acetate to create pores by applying water pressure. SEM analysis was performed to confirm that pores were formed. As a result, it was confirmed that abundantly fine pores were formed in the plasticization area. The interaction between CA and glycolic acid was ascertained through FT-IR, and it was proved that glycolic acid was not removed. The thermal stability and removal of the glycolic acid were verified by TGA analysis. As a result, it was confirmed that glycolic acid was not removed even after water pressure treatment and caused a plasticizing effect. Surprisingly, the porosity of this membrane was 83.6% and the average pore size was 192 nm.