Revisiting the condensation reaction of lignin in alkaline pulping with quantitativity part I: the simplest condensation between vanillyl alcohol and creosol under soda cooking conditions

Abstract The condensation reaction of lignin is believed to interfere with delignification in alkaline pulping processes, without any clear evidence, which has motivated us quantitatively revisit it. This paper the first a series, and hence we employed simplest model system using 4-hydroxymethyl-2-methoxyphenol (vanillyl alcohol, Va) 2-methoxy-4-methylphenol (creosol, Cr) under soda cooking conditions. α -5-type product between these compounds [VaCr, 2-(4-hydroxy-3-methoxybenzyl)-6-methoxy-4-methylphenol] was identified quantified as exclusive. VaCr yielded mole amount 24%, 46%, 62%, or 72% based on that disappearing Va at time 120 min when ratio initial concentration Cr 1.0, 2.5, 5.0, 7.5, respectively. These yields an HPLC analysis solution obtained by treatment sole compound same conditions suggested formation self-condensation products even treatments containing Cr. results comprehensively progresses more readily than factors behind this will be topic our next paper.