Controlled Dispersion and Setting of Cellulose Nanofibril - Carboxymethyl Cellulose Pastes

This work investigated the redispersion and setting behavior of highly loaded (~ 18 wt.% solids in water) pastes cellulose nanofibrils (CNFs) with carboxymethyl (CMC). A single-screw extruder was used to continuously process CNF + CMC into cord. The adsorption onto CNFs assessed through zeta potential titration which revealed a surface charge change ~ 61% from ? 36.8 mV 0.094 mmol/g COOH for pure -58.1 0.166 degree substitution 0.9. Dried adsorbed found be fully redispersible water re-extruded back cord without any difficulties. On other hand, chemical treatment hydrochloric acid, carbodiimide crosslinker, or two wet strength enhancers (polyamide epichlorohydrin polyamine epichlorohydrin) completely suppressed dispersibility previously observed dried-untreated CMC. Turbidity quantify level achieved by untreated chemically treated both strong alkaline solution (0.1 M NaOH). Depending on used, FTIR analysis presence ester, N-acyl urea, anhydride absorption bands were attributed newly formed linkages between CNFs, possibly explaining behavior. Water uptake differently dried materials agreed turbidity results.