Diogo de Lucca Sartori

Sugarcane bagasse and castor oil polyurethane adhesive-based particulate composite

This paper discusses the potential use of sugarcane bagasse in two different fiber lengths (5 mm and 8 mm) of the same density as a raw material for the production of particleboards, using castor oil-based two-component polyurethane adhesive. The quality of the product that can be manufactured industrially was evaluated based on density, thickness swell (TS), absorption (WA), modulus of elasticity (MOE), modulus of rupture (MOR) in static bending and internal bond (IB), according to the Brazilian NBR 14.810:2006 standard. The results revealed a significant difference between the particleboards made with 5-mm-long fibers and those made with 8-mm-long fibers. An analysis by scanning electron microscopy (SEM) indicates that the interparticle spaces are filled with castor oil-based two-component polyurethane adhesive, contributing to improve the physicomechanical properties of the particleboards. A durability assessment based on accelerated aging tests shows that waterproofed particleboards can be used in moist environments.

Durability Evaluation of Agro-Industrial Waste-Based Particle Boards Using Accelerated Aging Cycling Tests

The degradation of agro-industrial waste-based particle boards reinforced with sugar cane bagasse was evaluated by comparing their physical and mechanical properties. The particle boards were prepared with sugar cane bagasse particles (85% by weight of composite) and mixed with bi-component polyurethane resin based on castor oil (15% by weight). After mixing for 2 to 3 min, the resulting mixtures were pre-pressured. Standard molding conditions were: temperature, 100°C; pressure during heating, 5 MPa; and heating time, 10 min. The dimensions of the particle boards produced in the laboratory were 0.40 m x 0.40 m x 0.01 m. The boards were cut into testing specimens with dimensions 0.25 m × 0.05 m × 0.01 m. The accelerated aging test was carried out based on the ASTM D 1037 standard in order to determine the main factors that cause degradation and to identify their influence. The test consists of cycles of six treatment steps, i.e., immersion in water at 49°C for 1 h, steaming at 93°C for 3 h, freezing at-12°C for 20 h, drying at 99°C for 3 h, steaming at 93°C for 3 h, and drying at 99°C for 18 h. This cycle was applied six times for all specimens. Modulus of rupture (MOR), modulus of elasticity (MOE), internal bonding strength (IB), water absorption (WA%) and thickness swelling (TS%) were measured before and after the cycles of accelerated aging. The performance of the particle boards before accelerated aging presented acceptable mechanical performance, MOR: 21.86 ± 2.16 MPa, MOE: 2.77 ± 0.26 GPa, and IB: 1.18 ±0.40. The performance of the particle boards decreased after accelerated aging showed, MOR: 6.25 ± 0.70 MPa, MOE: 0.52 ± 0.10 GPa, and IB: 0.15 ± 0.07. The results were influenced by the temperature, relative humidity and warm water. After the accelerated aging process, the materials showed mechanical behavior similar to Low-Density grade Particleboard (LD1).

PAINEL AGLOMERADO DE RESÍDUOS AGROINDUSTRIAIS

The present study aimed to develop particleboards of low density with peanut shell, coconut husk fiber green (hybrid) and two-component polyurethane resin based on castor oil. The experimental panels were manufactured with particles up to 8mm and 15% polyurethane resin. The pressing was carried out at 5.0 MPa for 10 minutes at 100°C of temperature. The physical-mechanical properties of the material were determined as recommended by ABNT 14810:2006. The results demonstrated a mechanical performance that meets the recommendations established by normative ANSI A208.1-1999 and ABNT 14.810-2:2006.