木材内における2, 4-トリレンジイソシアナートの気相反応

抄録

In order to improve the properties of wood, the vapor phase reaction of 2, 4-tolylenediisocyanate (TDI) with heartwood of Hinoki (Chamaecyparis obtuse Sieb. et Zucc.) in nitrogen atmosphere was investigated.
As the results, the formation of urethane in wood was identified in its infrared spectrum. The nitrogen content in the treated sample reached almost a constant value after 2 hours of reaction, and the maximum nitrogen content in non-swelled wood and pre-swelled wood with pyridine was about 1.2% and 3.5%, respectively. It was recognized that the reaction of TDI took place in the amorphous region near the surface of wood and 85∼95% of the urethane formed in wood was apparently combined with wood components.
The hygroscopic and swelling properties of treated wood decreased with increasing nitrogen content, and in the equilibrium state at 20°C and 93% relative humidity the moisture-excluding efficiency and anti-swelling efficiency of wood containing 5.4% nitrogen were 45% and 50%, respectively. Also, the compressive strength and the modulus of elasticity in bending increased with increasing nitrogen content, and the loss of toughness was not recognized.