The brightness response of lignocellulosic and cellulosic fibers to hydrogen peroxide

The physical and chemical characteristics of predominantly juvenile (PJ) and predominantly mature (PM) pulp obtained from the same black spruce tree (Picea mariana) have been investigated before and after hydrogen peroxide bleaching, to evaluate the differences observed in their individual brightness response. In addition. parallel bleaching was conducted using abaca. a typical textile fiber, and also in-house C manufactured holocellulose of PM black spruce. Parallel experiments provided additional information on the influence of lignin structural characteristics, metal distributions. and fiber quality on the relative degree of physical degradation and brightness enhancement noticed between PJ and PM fibers. In general, after either hydrogen peroxide bleaching or oxygen delignification, PM displays a higher propensity to brighten, but also tends to degrade at a faster rate than PJ. This result might be induced by the different metal distributions found in the fibers and may be a direct consequence of lignin structural characteristics and metal affinity for the fiber surface. Textile and holocellulose fibers lend supporting evidence for the brightness differences observed in PJ and PM fibers.