Colorimetric parameters have potential to differentiate tree species through their wood type. Therefore, this can be used to aid the inspection of illegal trade. Thus, considering the need to identify species with precision and speed, this study aimed to explore the potential of these parameters in order to characterize wood of some species of native Myrtaceae from the Araucaria Forest: Campomanesia xanthocarpa Berg., Eugenia pyriformis Cambess., Myrcia retorta Cambess., and Plinia Peruviana (Poir.) Govaert. Twelve trees were collected randomly – three per species – for the removal of a disc at diameter at breast height (DBH). We took samples from three regions of the disc (next to the bark, intermediate and next to the pith) and analyzed them in three anatomical sections (transversal, radial and tangential) by the system CIE L*a*b* using a bench colorimeter. We analyzed the data based on the following criteria: test of means in order to differentiate species, quantitative factor analysis (considering the region of the disc and the anatomical section as factors), and principal components analysis (PCA). Then, we used the original spectrum and the values of parameters L*, a* and b* in order to verify the distribution of the species. The analysis determined that the species present different values for the colorimetric parameters. In addition, the factors region of the disc and anatomical section have specific influence for each species. Finally, the PCA indicated that only E. pyriformis differs from the others.

In this work, recycled papers werereinforced with Eucalyptus sp. NFC obtained through mechanical defi brillation in a grinder. Addition of 10 % provided the best results, with improvement of tensile, burst and tear resistance of 97, 133 and 104 %, respectively, in comparison to normal papers. The papers' apparent density signifi cantly increased with the addition of NFC due to the lower porosity and more compact structure presented when compared to the treatments without the addition of NFC. The addition of NFC signifi cantly improved the physical and mechanical properties of the recycled papers when compared to normal papers.

Cellulose: an abundant, biodegradable and renewable plant material that is available all around the globe, from which nanofibrillated cellulose (a homogeneous suspension of fibers with nanometer-scale diameters) can be extracted. The nanofibrillated cellulose, in what concerns its range of application, may completely or partially replace other materials due to its particular physical properties. Knowing its characteristics and properties is important in understanding its behavior in various applications. In light of this remarks, the objective of this research was to extract the nanocellulose from bleached eucalyptus pulp through mechanical milling to characterize the resulting nanofibrillated cellulose and compare both. The nanofibrillated cellulose presented a very distinct appearance in relation to the original cellulose pulp when they were analysed in the same concentrations, demonstrating greater water absorption and fibrillar interweaving. The nanofibrillated material showed different responses in comparison to the original in terms of dimensions, thermal stability, crystallinity, viscosity, and degree of polymerization. The nanofibrillated cellulose displays the same chemical composition through infrared analysis and has diameters of around 21.7 nm, smaller than the cellulose diameter of 11.4 μm. The nanofibrillated cellulose also exhibits lower thermal resistance: its decomposition temperature was about 20 ºC lower than that of the original cellulose pulp, and its crystallinity index has decreased. As for viscosity and degree of polymerization, there was reduction of 25% compared to the original material. The results presented hereby indicate that the nanofibrillated cellulose has unique features in relation to the original cellulose pulp, which supports its application as an alternative to existing materials.

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The basic density is the main technical property of the wood due to the fact of the easy determination and correlation with the others wood properties. In this article, it was evaluated wood chips from a five-years-old Eucalyptus grandis in three different silvicultural treatments for pulp and paper production. First, a conventional kraft pulping was executed in the same conditions and then submitted to some elemental chlorine free (ECF) bleaching process to achieve the target brightness of 88 ± 1% ISO. The bleached pulps were refined in a Jokro Mill at 0, 2250, 4500 and 6750 revolutions and their physical, mechanical and optical properties were analyzed. The statistical analysis indicated a difference in the wood basic density from the different silvicultural treatments. The yield of the pulping process was not affected by the variation of the wood basic density. The denser wood had the advantage of a lower specific wood consumption while the disadvantage was a greater difficulty in the delignification and a decrease in the selectivity of the pulping process. The denser wood was the one with the best bleachability and the one that most consumed chlorine in the bleaching process. The increase of the wood density caused gains in the fisical and optical properties of the bleached pulp and losses in the mechanical properties.The optical properties of the pulps from denser woods are more resistant than the negative effects of mechanical properties.