Bending properties of TCMTB-treated Southern pine sapwood using supercritical carbon dioxide impregnation process
Gyu-Hyeok Kim, S Kumar, E S Demessie, K L Levien, J J Morrell
The effects of elevated pressure and treatment with thiocyanomethylthiobenzothiazole (TCMTB) on the bending properties of Southern pine sapwood were evaluated at pressures ranging from 1,800 to 3,600 psi. All bending properties were affected to some extent by supercritical fluid treatment. Modulus of elasticity and work to maximum load were not significantly affected by pressure levels. Modulus of rupture differed among individual pressure levels, but the effects on bending strength were less definitive. TCMTB retention had little or no effect on properties, suggesting a lack of chemical interactions between the lignocellulosic matrix and this biocide. The effect of treatment on bending properties was unexpected as previous trials on smaller specimens and selected composite panels had shown no negative effects. Further trials of other wood samples with increased replication are planned to more fully understand potential treatment effects on strength properties.