The Reaction of Wood Pulp with α,β-Amic Acids

Abstract

In this study, liquid anhydrous ammonia has been used as a pre-swelling treatment for wood pulp and as a solvent for the reactants. With the single-step reactions, slightly more crosslinking resulted when the reactant was applied from liquid ammonia than from aqueous media. The multiple bake reactions, however, resulted in higher total degree of substitution (DS) values on the order of 1.0 and greater, but also in disproportionately more crosslinking. Degradation was minimal by the use of aqueous ammonium succinamate from single pad bake reactions, resulting in an average DP of 331. This is compared to the multiple pad-bake reactions with aqueous ammonium succinamate and with suc cinic anhydride in liquid ammonia media, which resulted in very low DP values ranging from 155 to 200. Discoloration of the derivatives accompanied the increases in DS and reductions in DP. Some cellulose derivatives appear to have been dissolved in concentrations to 4% (w/v) in 10 to 13% aqueous sodium hydroxide at 5.5°C and up to 0.7% in DMSO by refluxing. Infrared analyses have shown the material coagulated from the aqueous sodium hydroxide solutions to be pure cellulose, and the coagulant from DMSO solution to be cellulose hemisuccinate. Both infrared crystallinity index determinations and x-ray diffraction patterns indicated that the cellulose regenerated from aqueous sodium hydroxide solution was suhstantially crystalline.