Phenolic Foam from Oxidatively Degradated Lignosulphonate

Abstract

High molecular weight lignosulfonate was oxidatively degrdadated into lower molecular weight fractions, the resulting components were conducted to formulate resol resin with phenol and formaldehyde in an alkaline condition, in which 50% phenol was substituted. The modified resol resin was successfully applied to prepare phenolic foam using appropriate combinations of flowing agents. N-pentane was found to be suitable as the foaming agent. Sulphuric acid (50% aqueous solution, w/w) and Tween-80 were used as catalyst and surfactant, respectively. The obtained foams showed satisfactory mechanical properties and excellent uniform cells, which can comply with the required specifications for its practical utilization.