COMPARATIVE-STUDY OF CARIBBEAN PINE (PINUS-CARIBAEA L) WOOD AND BARK DIOXANE LIGNIN

The objective of this paper was to depict some differences between Car ibbean pine bark and wood lignin. Gas chromotography (GC) of nitrobenz ene oxidation products of extracted wood and bark meals and of corresp onding dioxane lignins was performed. The isolated lignins were submit ted to IR and UV spectrometry, gel permeation chromatography and diffe rential thermo-gravimetry. The data obtained indicate differences in t he contents of condensed bis-guaiacyl structures in the lignins. Conte nts of phenolic hydroxyl and alpha-carbonyl groups in both lignins do not markedly differ. There are also certain differences in the thermos tability and the molecular weights of compared dioxane lignin preparat ions.