Caracterização anatômica, química e físico-mecânica da madeira de paricá (Schizolobium amazonicum) para produção de energia e polpa celulósica

• Autor(a) principal: Vidaurre, Graziela Baptista
• Data de Publicação: 2010
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/541
• topic: Paricá; Propriedades; NSSC; Anatomia; Paricá; Properties; NSSC; Anatomy; CNPQ::CIENCIAS AGRARIAS::RECURSOS FLORESTAIS E ENGENHARIA FLORESTAL::TECNOLOGIA E UTILIZACAO DE PRODUTOS FLORESTAIS

This work aimed to evaluate the influence of age and position on the trunk (radial and longitudinal) on the anatomic, chemical, physical and mechanical properties of Schizolobium amazonicum (paricá) wood and neutral sulphite semi-chemical pulping (NSSC), compared to Eucalyptus grandis wood. Paricá wood originated from commercial plantations located in the region of Dom Eliseu, Pará, Brazil. Four trees were used for each age. A disc was removed from the transversal section at the base of each log for anatomical and chemical analysis and samples were taken from the diametric board for determination of the physical-mechanical properties. Pulping was made in different loads of sulphite (Na2SO3) and different cooking times. Bleaching was performed in the QPFAS sequence. Radial variance in the length of the fibers was more pronounced than those found longitudinally and in function of age.. The mean values of the length of the fibers, width, diameter and thickness of the wall were, respectively, 1.07 mm, 33, 26, 24, 56 and 3.85 μm. Lumen width was superior to the values normally found for Eucalyptus wood. .Little consistency was found in the effect of age on the chemical composition of the wood. When compared with the Eucalyptus wood, Klason lignin content was high, but the content of soluble lignin was low (mean of 1.90%), and the S/G CHECAR SIGLA EM INGLES relation and uronic acid content were low (1.07 and 1.0 %, respectively). The extractive content was low compared to other native essences, but within the range found for eucalyptus wood. Carbon content was on average equal to 45% for all ages. Parica wood contained high humidity content after being harvested. Density was low, tending to increase with age. Density mean for 5-year-old wood was equal to 262 kg/m3 and for 11- year-old wood, equal to 303 kg/m3. The mean anisotropic factor was 1.95, considered normal and the mean volumetric contraction was 9.32%, both below those found for eucalyptus wood. The mechanical property values are considered low (which was expected due to the low density) at all ages, with tendency to increase with age, except for the age of nine. This decrease at the age of nine was also observed in the density values and in some anatomical parameters and can be explained in function of the planting being performed with seeds, without control of this variable. The parica pulps presented lower yield and brightness than the eucalyptus pulps and greater consumption of energy during chip processing. Under the condition of 16% of sulphite and 150 min cooking time, yield and whiteness for parica and eucalyptus woods were, respectively, 75 and 77% and around 70 and 80% ISSO. The resistances of the parica wood papers were slightly lower than those of the eucalyptus wood papers.