Development of Lignin modified phenolic resin using Soda-AQ lignin

Abstract

Soda-AQ (Antraquinone) lignins derived from Japanese cedar (softwood) and Eucalyptus (hardwood) were used to investigate their application to novolak type phenolic resin. As a result of thermosetting reaction evaluation using acetone extract of soda-AQ lignin with hexamethylenetetramine (hexamine) as curing agent, it was confirmed that lignin of Japanese cedar gave better thermosetting reactivity than that of Eucalyptus. In addition, novolak type lignin-modified phenolic resin was synthesized using acetone extract of soda-AQ lignin, then it was confirmed that lignin of Japanese cedar was also superior to that of Eucalyptus in terms of compression molding material properties. Furthermore, novolak type ligninmodified phenolic resin was synthesized using crude soda-AQ lignin of Japanese cedar. Although falling short in terms of thermal decomposition resistance, the resin showed higher mechanical properties and higher heat resistance than those of petroleum-derived phenolic resin in transfer molding material properties.