Molecular Response of Lignophenols for High Energy Input II: Plasticizing Performance of Low Molecular Weight Fractions

Lignocresol was synthesized from Hinoki cypress (Chamaecyparis obtusa) through the phase-separation treatment with p-cresol and 72% sulfuric acid. Thermal responses of lignocresol were observed around 160°C, which is attributed to existence of unstable sites. Molecular rearrangements associated with the cleavages of benzyl aryl ether linkages improved thermal stabilities of lignocresols. Low molecular weight units formed by the molecular rearrangements work as plasticizer of lignocresol. The grass-transition temperatures (Tg) and solid-liquid transition temperatures of lignocresols were shifted down with increasing ratios of low molecular weight units. The results indicated that low molecular weight units have the function as plasticizer, forming a new application of lignophenol.