Adilson R. Gonçalves,* Priscila Benar, Sirlene M. Costa, Denise S. Ruzene,

Regina Y. Moriya and Sandra M. Luz

Departamento de Biotecnologia - FAENQUIL

Cx. Postal 116

CEP 12.600-970

Lorena, SP, Brazil

Phone: 55-12-3159-5033

E-mail: adilson@debiq.faenquil.br

In this paper processes developed in our laboratory are described: the use of sugarcane bagasse and straw, two byproducts from the sugar and alcohol industries. Previously two separation methods were adopted: steam explosion and chemical pulping. Biological pre-treatment of sugarcane bagasse with Panus tigrinus and Ceriporiopsis subvermispora fungi was also carried out prior to the pulping. Bagasse and straw samples were submitted to alkaline and organosolv (acetosolv and ethanol/water) pulping, with and without argon pressure. The obtained pulps were characterized with respect to kappa number, viscosity, and chemical composition. Pulps were bleached with xylanases, benzylated and used in composites. Isolated lignin was oxidized in both alkaline and acidic media and the kinetics followed by UV and FTIR spectroscopies. Resol formulations were also obtained with lignins. Best viscosity of the pulps was 12 cP with kappa number 20, similar to industrial processes, showing that this pulp can be used for obtaining cellulose derivatives. Pressure also has a significative influence on yields and quality of pulps. Xylanases from different sources can decrease the kappa number over 70% after alkaline extraction, while maintaining the viscosity. Fungic treatment of sugarcane bagasse furnished pulps with up to 50% lower kappa number. Benzylated pulps and raw materials have good compatibility with polypropylene and composites were obtained with similar mechanical properties of industrial products. Lignin oxidation followed a pseudo first order kinetic with activation energy of 9-15 kJ^.mol^-1. Resols obtained with acetosolv and formacell lignins can be used to replace phenol in phenol-formaldehyde resins.