ABSTRACT A wide range of materials for the development of new products can be obtained from natural resources. Good examples of these materials are lignocellulosic wastes, which are a good alternative for the production of particleboards. This study aimed to evaluate the feasibility of using cotton wastes in association to eucalyptus particles in the production of particleboards. Cotton waste proportions used were 0, 10, 20 and 30%. Urea formaldehyde (UF) adhesive was applied at 12%, based on dry the weight of particles. Physical and mechanical tests were performed in order to evaluate panels. Water Absorption (2 and 24 h) and Internal Bond (IB) showed not significant effect with increased percentage of cotton waste. Thickness Swelling (2 and 24 h) of particleboards increased with increased percentage of waste material. The Modulus of Elasticity for cotton waste particleboards ranged from 726.47 ± 99.98 to 205.12 ± 66.24 MPa, while the Modulus of Rupture ranged from 8.63 ± 1.39 to 3.87 ± 0.75 MPa. According to results, cotton wastes could be added to particleboards up to the percentage of 9%, being indicated for the manufacture of some types of furniture such as doors and sides.

The present study was to evaluate the effect of polyethylene terephthalate (PET) particle sizes on the mechanical and physical properties of extruded fiber-cement composites with different particle sizes combined to cellulose pulp in the production of fiber cement by the extrusion process. The design consisted of four formulations, one composed of 5% cellulose and the other three with 2.5% cellulosic pulp and 2.5% of PET particles with different particle sizes. Physical, mechanical and microstructural tests were performed without aging cycles and after 200 and 400 accelerated aging cycles. The degradation of vegetable fibers in the cement and the decrease of properties with aging was observed. PET particles were more resistant in alkaline environment and did not degrade. However, particle size did not exert great effect in the physical and mechanical properties of the composite. Thus, the use of PET particles shows potential as a reinforcement for fiber-cement composites.