Oxidation of Spruce and Pulps

TEMPO is a stable radical that can be used for a wide variety of oxidation reactions in organic chemistry. Softwood and hardwood 

A birefringence test confirmed the presence of nanofibers with diameters in the range of 1.6-3.8 nm. The oxidation of spruce is more efficient than the oxidation of eucalyptus. Spruce yields higher carboxylate contents and nanofiber yields. 

In summary, the TEMPO-mediated oxidation is a promising technique applicable for a variety of ceUulosic materials. A high reaction rate and yield, high selectivity and a low degradation of the substrate is obtained. Both hardwood and softwood can be used for 

The effect of chemical modification of cellulose nanofibers on the properties of PLA nanocomposites has been investigated (44). Ac-etylated nanofibers, with a degree of substitution 1.07, were isolated from acetylated kenaf fibers by a mechanical procedure. The acet-ylated nanofibers were found to be more hydrophobic. Both crystallinity and thermal stability of acetylated nanofibers were lower in comparison to the non-acetylated nanofibers. 

Nanocomposites were prepared by premixing PLA master batches, with both acetylated nanofibers and non-acetylated nanofibers. These master batches were eventually diluted to their final concentrations of 5% in the course of the extrusion. 

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