Urea formaldehyde and cellulose nanocrystals adhesive: studies applied to sugarcane bagasse particleboards

Abstract

The aim of this research was to investigate the behavior of urea formaldehyde (UF) adhesive based particleboards using sugarcane bagasse (SCB), with and without the addition of cellulose nanocrystals (NCC). In the first step of this research study, the interaction between UF and the NCC was evaluated. The NCC were dispersed in the UF, in different proportions (0, 0.5, 1, 2, 3 and 5%). Subsequent to this, the mixtures were dried, milled, and put in molds, to produce flexural specimens. The second step involved evaluation of the interaction between the NCC, UF, and SCB. After sonication, the NCC and UF were applied on the SCB particles to produce particleboards. They were evaluated according to the modulus of elasticity and rupture, water absorption (WA), and thickness swelling. The viscosity of the mixture of NCC and UF increased according to the NCC increase load. At 5% of NCC load, the viscosity increased greatly, which prevented adhesive dispersion in the particleboard. The thermogravimetric analysis of UF showed that better conditions of processing were at 160 °C for 8 min, so these parameters were used to produce the specimens. SCB is a promising raw material for particleboard, and its potential to produce SCB particleboards with relatively good performance was demonstrated. For the particleboards specimens, the best performance was observed with 1% of NCC. Particleboards did not show improvement compared with UF specimens, probably because bond links were not sufficient. Addition of NCC in UF increased the liquid suspension viscosity, and the specimens showed a better mechanical performance.