EFFECTS OF EXTRACTION ON REACTION OF BARK EXTRACTS WITH FORMALDEHYDE

Southern pine (Pinus taeda), sweetgum (Liquidambar styraciflua), White oak (Quercus alba), red oak (Quercus falcata), and yellow-poplar (Liriodendron tulipifera) barks were extracted with sodium hydroxide, sodium sulfite, and sodium carbonate at various concentrations and temperature. These extracts were reacted with 30% formalin at 60-degrees-C for 3 hours. Free formaldehyde and methanol in reaction mixture were quantitatively determined by GC analysis with samples withdrawn at various reaction times elapsed. Among all species and extraction methods combined, southern pine bark extracts of sodium hydroxide were most reactive toward formaldehyde and yellow-poplar bark extracts were the least reactive. The reactivities of sodium carbonate extracts were lowest compared with extracts of other two chemicals. The quantities of free formaldehyde decreased rapidly in the early stage of the reaction, then slowed down after 30 minutes of reaction, except the sodium carbonate extracts. The Cannizzaro reaction was observed in all reaction mixtures of bark extracts and formaldehyde.