The objective of this work was to study the particleboard production using
Eucalyptus particles, sisal filaments, coconut filaments (coir) and sugarcane
bagasse particles (SCB). All particleboards were made in three layers (face /
core / face) using urea-formaldehyde adhesive (UF). Coir and sisal filaments
were used in association with Eucalyptus particles, only in the inner layer (core),
in proportions of 0, 10 and 20%. The SCB particles were separated into pith and
fibers and the particleboards were made using only fibers and using fibers on the
faces and pith in the core. SCB particleboards were also manufactured using 1%
of cellulose nanocrystals (NCC), by adhesive mass, on the faces of the
particleboards. The proportion of NCC was defined using urea-formaldehyde
specimens, reinforced with different proportions of NCC (0, 0.5, 1, 2, 3 and 5%).
For the particleboards production, a pressing cycle was used with the following
characteristics: temperature of 160°C, pressure of 4 MPa and time of 8 minutes.
The properties evaluated were: water absorption (WA), thickness swelling (TS),
density, compaction ratio, modulus of elasticity (MOE), modulus of rupture
(MOR), internal bond (IB) and thermal conductivity (TC). The particleboards
reinforced with sisal did not show satisfactory results for most of the properties
evaluated (MOE, MOR, WA, IB and TC), but those reinforced with coconut,
showed properties very similar to the particleboards made only with Eucalyptus
particles, demonstrating the potential of this material. The filaments of sisal
formed tufts that impaired the dispersion of the adhesive inside the tufts,
reflecting in poor physical-mechanical properties. The specimens of UF
reinforced with NCC (1, 2 and 3%) presented higher results (MOE and MOR)
than non-reinforced specimens did, but the same was not observed when the
NCC were applied in the SCB particleboards. NCC were probably able to bind
with the adhesive, decreasing the amount of sites for the bonds between the
adhesive and SCB particles. Particleboards made with fibers and fibers/pith
showed properties statistically equal for most properties (MOE, MOR, WA and
TC). SCB showed potential for MDP production.