On the screenings of sulfite pulp (II)

Nitrobenzene oxidation of protolignin and sulfite phenol-lignin

Abstract

We investigated alkaline nitrobenzene oxidation of pine wood and sulfite screenings. The results led us to the following conclusions:
1). In both pine protolignin and its sulfite screenings (phenol-lignin) the building unit which consists of p-oxyphenyl nucleus is present in small portion.
2). The vanillin yield of the sulfite screenings decreases to ca. 40% of the normal yield of pine heartwood.
This reduction of vanillin yield is observed in the earlier stage of sulfite cooking reaction.