TY - JOUR

T1 - Particleboards Bonded by an Imidazole-Based Adhesive System

AU - Scharf, Alexander

AU - Popescu, Carmen-Mihaela

AU - Dernegard, Henric

AU - Oja, Johan

AU - Ormondroyd, Graham

AU - Medved, Sergej

AU - Sandberg, Dick

AU - Jones, Dennis

PY - 2023/11/17

Y1 - 2023/11/17

N2 - Particleboards with different combinations of the adhesive material imidazole, citric acid, and sorbitol were produced. Softwood sawdust from a Swedish sawmill was mixed with an aqueous solution of the chemicals and then dried to 0% moisture content prior to pressing. The boards were pressed to a target density of 700 kg m3 at either 200  C or 220  C for 10 min. The hygroscopic and mechanical properties of the boards were clearly better at 220  C than 200  C for all used chemical combinations. A combination of imidazole (14.4 wt%) and citric acid (11.3 wt%) led to the best results, where the thickness swelling after 24 h of water immersion was 6.3% and the internal bonding strength was 0.57 MPa. The modulus of rupture and modulus of elasticity were 3.3 MPa and 1.1 GPa, respectively. Cyclic accelerated weathering showed exceptional stability with a thickness change after boiling and drying of only 2.1% compared to the initial dry thickness. This study indicates that the presence of imidazole leads to greatly improved hygroscopic properties and good internal bonding strength when used in particleboards.

AB - Particleboards with different combinations of the adhesive material imidazole, citric acid, and sorbitol were produced. Softwood sawdust from a Swedish sawmill was mixed with an aqueous solution of the chemicals and then dried to 0% moisture content prior to pressing. The boards were pressed to a target density of 700 kg m3 at either 200  C or 220  C for 10 min. The hygroscopic and mechanical properties of the boards were clearly better at 220  C than 200  C for all used chemical combinations. A combination of imidazole (14.4 wt%) and citric acid (11.3 wt%) led to the best results, where the thickness swelling after 24 h of water immersion was 6.3% and the internal bonding strength was 0.57 MPa. The modulus of rupture and modulus of elasticity were 3.3 MPa and 1.1 GPa, respectively. Cyclic accelerated weathering showed exceptional stability with a thickness change after boiling and drying of only 2.1% compared to the initial dry thickness. This study indicates that the presence of imidazole leads to greatly improved hygroscopic properties and good internal bonding strength when used in particleboards.

U2 - 10.3390/ma16227201

DO - 10.3390/ma16227201

M3 - Article

C2 - 38005130

VL - 16

JO - Materials

JF - Materials

SN - 1996-1944

IS - 22

M1 - 7201

ER -