Application of Biobased Phenol Formaldehyde Novolac Resin Derived from Beetle Infested Lodgepole Pine Barks for Thermal Molding of Wood Composites

In this study, wood particles were thermally molded into composites using a novolac resin derived from beetle infested lodgepole pine barks with three different resin-to-wood filler weight ratios (3:7, 5:5, and 7:3). Control composites were made using a lab synthesized novolac resin without bark for comparison. Results showed that mechanical properties of the composites varied with the resin-to-filler ratios. Bark-derived resin improved the tensile strength of the composites at resin to filler weight ratio of 5:5. Meanwhile, at all three resin-to-filler weight ratios, the composites made using the bark-derived resin showed an improved water resistance than the control composites. However, the composites made with the bark-derived resin exhibited a slightly lower thermal stability than the control composites. This study demonstrated that bark derived novolac resins have great potential for application in thermal molding of wood composites to improve water resistance compared with novolac resins without bark components.