UV-Resonance Raman (UV-RR) spectroscopy with laser beam excitation source of 325 nm was applied to a solid-state study of chromophores in Eucalyptus globulus kraft pulps. The amount of chromophore structures in pre-bleached/fully bleached pulps absorbing at 325 nm linearly correlated with signal at ca 1600 cm in UV-RR spectra. The characteristic vibrations from particular pulp chromophore struc...

Canola straw can be used as a raw material for the production of chemimechanical pulp (CMP). In this work, chemimechanical pulp was first produced from canola straw, and then the bleaching performance of the produced chemimechanical pulp was investigated under different conditions (dosages of NaOH and Na2SO3, time, and temperature). The results showed that the yield of chemical pretreatment in ...

Ethanol/water organosolv pulping was used to obtain sugarcane bagasse pulp that was bleached with sodium chlorite. This bleached pulp was used to obtain cellulosic films that were further evaluated by Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). A good film formation was observed when temperature of 74 degrees C and ba...

The lipophilic extractives of Eucalyptus globulus, Eucalyptus grandis, Eucalyptus urograndis, Betula verrucosa and Acacia mangium woods and of the corresponding ECF bleached kraft pulps, were characterized by GC-MS. The five hardwoods showed significant differences in the content and composition of the main families of extractives, namely fatty acids, long chain aliphatic alcohols and sterols. ...

The removal of transition metal ions is crucial for improving the efficiency of subsequent peroxide bleaching. Acid-washing and chelation have been proposed for such a purpose. However, their influences on the Mg(OH)2-based peroxide bleaching of hardwood pulps at a high consistency have not been well documented in the literature. In this work, we studied the influence of acid-washing using sulf...

Bacterial, mechanical, or chemical irritation to the pulp may result in tissue necrosis and release of disintegration by-products that may penetrate tubules and discolor the surrounding dentin. The degree of discoloration is directly related to how long the pulp has been necrotic. The longer the discoloration compounds are present in the pulp chamber, the greater the discoloration. Such discolo...

The aim of the present work is to obtain a chemical-mechanical pulp (CMP) from poplar wood with improved properties, to be used in packing papers in place of more expensive softwood or hardwood pulp. For improving the CMP quality indicators, a preliminary treatment of the pulp has been carried out with a mixture of oxidizing enzymes produced from Phanerochaete chrysosporium, including lignin pe...

the effect of commercial xylanase enzyme in prebleaching of bagasse kraft pulp was investigated. xylanase enzyme from trichoderma viride was added to pulp at various doses of 5, 10, 25 and 50 iu/g pulp for reaction time 2h and then the enzyme treated pulp was bleached in d1ed2 sequences (using dioxide chlorine 4, 6, 8, 10% + alkaline extraction + dioxide chlorine 2% as active chlorine). the res...