(644d) Evaluating the Quality and Processability of Cotton Linter-Derived Cellulose Acetate By Analysis and Characterization of Native and Artificial Fines

Conversion of feedstock materials to cellulose acetate requires high quality dissolving pulp to process and produce adequate final product. All pulps from biomass contain some fraction of very short fibers called “fines”. Fines exhibit a high specific surface area and therefore higher bonding potential. The present work assesses the impact of fines on cotton linter acetylation by generating fines substitutes via grinding cotton linter to micro fibrillated cellulose (MFC) and adding to screened long fiber portions in varying contents. These “recipes” of various fine content are then acetylated. Their quality was evaluated using in situ thermal study during acetylation, filtration capability of ensuing cellulose acetate, and FTIR analysis of final product to assess degree of functional group substitution (DS). Results demonstrated that increasing MFC content of the cotton linter feedstock yielded a less filterable, lower DS material. The implications of this work indicate that industry may be best suited to remove fines from the material before processing. Additionally, this work points to future opportunities to investigate best methods to overcome processing difficulties related to fines in pulps.