| Abstract:The influence of etherification process parameters on fiber carboxyl content was studied by designing orthogonal experiments， and the effects of carboxyl group content on fiber morphology， crystalline structure， water retention capacity of wood fibers and its dispersibility in reconstituted tobacco were explored in this study. Finally， a comparison in reinforcement effect of original fibers and carboxymethylated fibers with different carboxyl group contents was carried out. The results showed that the order of these process factors affecting the fiber carboxyl group content was as follows： reagent dosage>fiber concentration>reaction time. The content of carboxyl group was proportional to reagent dosage and inversely proportional to fiber concentration with an optimum reaction time of 50 min. With the increase of carboxyl group content， the average width of carboxymethylated wood fibers increased， the length-weighted mean length increased first and then decreased， while the fine content decreased first and then increased. Besides， carboxymethylated wood fibers with higher carboxyl content groups showed a higher water retention value and could improve their dispersion uniformity in reconstituted tobacco sheet. Compared with sample of original wood fibers， rolled reconstituted tobacco sheet with carboxymethylated fibers （carboxyl group content≥0.65 mmol/g） indicated a 35.8%~106.6% increase in tensile strength. |
