Production and characterisation of self-blowing lignin-based foams

Abstract

Self-blowing lignin-furanic foams were produced using formulations comprising Kraft lignin and furfuryl alcohol as the major components. Diethyl ether, Tween 85 and sulphuric acid were used as blowing agent, surfactant and catalyst. The influence of the components and the ratio of furfuryl alcohol to lignin was investigated with regard to the foam density, mechanical properties, water absorption, thermal properties, and fire behaviour. Depending on the formulation, the density of lignin-furanic foams ranged between 60 and 320 kg m−3. Increasing the furfuryl alcohol content increased the density of the foams. Low-density foams were obtained with a higher proportion of diethyl ether. The compression strength and modulus of elasticity (MoE) of lignin-furanic foams also increased with foam density. All lignin-furanic foams showed good thermal stability and residual masses by thermogravimetric analysis. Cone calorimetric analysis showed that lignin-furanic foams have poor flammability and self-extinguish within few seconds.