Id. Suckling, COMPARISON OF THE OPTICAL-PROPERTIES OF RADIATA PINE TMP AND CTMP PULPS AND THE STARTING WOOD, Research of chemical intermediates, 21(3-5), 1995, pp. 275-286
The reflectivity, specific light scattering coefficients and specific
light absorption coefficients of earlywood and latewood in each ring f
rom three radiata pine discs were determined at 457 nm. Significant ri
ng-to-ring and within-ring variation was observed. A method was develo
ped to determine the light absorption spectra of the wood. Comparison
with that of TMP pulp showed that during refining a chromophore with a
maximum absorption at 430 nm was produced. It is suggested that this
is the same chromophore as that produced during light-induced yellowin
g of mechanical pulps, possibly an o-quinone. Chromophore formation wa
s less when sulfite was present.