Proton spin-lattice relaxation time measurements of solid wood and its constituents as a function of pH: part II

The proton spin-lattice relaxation times (T1H) for isolated cuoxam lignin and fully bleached cellulose were measured as a function of pH in the solid-state. These experiments provided the opportunity to examine for possible macromolecular connectivities that may be present between lignin and carbohydrates within softwood. These studies have shown that the molecular mobilities of the isolated polymeric constituents of wood are affected by the ionization of their functional groups at different pHs. The shapes of the plots of T1H as a function of pH for the two isolated polymers were dramatically different, while those for softwood were similar. This fact provides evidence supporting the notion that in wood, lignin and carbohydrates are intimately associated with each other.