2 research outputs found

    Synthesis and Characterization of Biobased Melamine Formaldehyde Resins from Bark Extractives

    No full text
    In this study, bark alkaline extractives from the mountain pine beetle (<i>Dendroctonus ponderosae</i> Hopkins) infested lodgepole pine (<i>Pinus contorta</i> Dougl.) was used to partially replace 30 wt % of melamine in formulating the biobased bark extractive–melamine formaldehyde (MF) resin. Results showed that the addition of the bark extractives and the type of solvent system used for resin formulation significantly affected the initial molecular weight, molecular structure, viscosity, curing behavior, postcuring thermal stability, and bonding performance of the resulting resins. The bark extractive–MF resins exhibited similar dry and wet bonding strengths to the laboratory made control MF resins formulated in the same type of solvent system. The liquid-state <sup>13</sup>C NMR study showed that bark extractives were reactants and incorporated into the resulting biobased MF resin structures. Bark extractives obtained from the mountain pine beetle infested lodgepole pine showed promise as a suitable partial replacement for melamine in MF resin formulations

    Characterization of Modified Phenol Formaldehyde Resole Resins Synthesized in Situ with Various Boron Compounds

    No full text
    In this study, three different boron compounds were used together with alkaline catalyst to synthesize phenol formaldehyde (PF) resole resins in situ. The resin curing behavior, molecular structure, bonding performance, and properties of resin-impregnated wood were investigated. Results showed that boron compound-modified PF resins had a lower degree of polymerization than the control PF resin made in the laboratory. The curing kinetics, molecular structure, and functional groups of the modified resins varied depending on the type of boron compounds used. The thermal stability of cured modified PF resins was slightly lower than that of laboratory-made control PF resin. Boron compound-modified PF resins exhibited dry and wet bonding strengths comparable to the those of the laboratory-made control PF resin. Wood impregnated using modified PF resins had comparable dimensional stability, mechanical properties and improved fire resistance than the wood impregnated using lab made control PF resin regardless the type of boron compounds used
    corecore