Structural, morphological, and thermal properties of cellulose nanofibers extracted from waste paper

Abstract

The disposal of waste paper typically occurs through conventional garbage methods, leading to environmental pollution and the inefficient use of natural resources. This study seeks to transform these discarded materials into a valuable resource, thus mitigating a detrimental environmental impact and enhancing recycling efforts. The research employed both chemical and mechanical techniques to isolate cellulose nanofibers (CNFs) from waste paper. The papers were treated with 17.5% sodium hydroxide to remove certain minerals, followed by bleaching with sodium hypochlorite. This process effectively eliminated hemicelluloses, pectin, and lignin. Acid hydrolysis using hydrochloric acid was also performed at different concentrations, durations, and temperatures to improve treatment results. FTIR analysis showed that a sample treated with 3 M acid at 100 °C for two hours had the highest crystallization index. XRD confirmed a peak crystallinity index of 70%. SEM indicated optimal fibrillation at ambient temperature after two hours. TG analysis revealed a maximum degradation temperature of 361.6 °C, leading to 90% fiber destruction. The combination of chemical and mechanical techniques was highly effective for extracting CNFs.