Effect of temperature on the dynamic mechanical properties of resin film and wood
Publication Name: Forest Products Journal
The objective of this research was to investigate the heat resistant performance of structural adhesive as compared with wood samples. Phenol-resorcinol-formaldehyde (PRF) and two wood species, southern pine (Pinus palustris) and Douglas-fir (Pseu-dotsuga menziesit), were investigated. Uniform thin cured resin films and wood samples were carefully prepared. Dynamic mechanical analysis (DMA was employed to evaluate the fixed frequency oscillation properties of these samples over the temperature range of 60 to 250 ¡C. Shear storage moduli, shear loss moduli, and tan 8 values of the prepared samples were obtained through the DMA temperature scan and isothermal testing. DMA temperature scan tests showed that the storage moduli of the tested materials decreased as the temperature increased. At the same temperature level, PRF resin films had higher storage moduli than that of the wood samples. No obvious difference was found between the two wood species in their dynamic performances. The DMA isothermal tests results indicated that the storage moduli of cured rein films increased with prolonged time at the four different temperature levels (90, 150, 200, and 250 ¡C), while the loss moduli and tan 8 values decreased with prolonged time. The moduli and tan 8 values of wood samples decreased dramatically with prolonged time at 250 ¡C, while changed slightly at temperatures of 90, 150, and 200 ¡C.