Phenolic and lignophenolic closed cells foams: Thermal conductivity and other properties

Lignin, extracted from sugarcane bagasse, was used as a partial substitute of phenol in phenolic closed cells foams. The thermal conductivity of phenolic and lignophenolic thermosets and phenolic and lignophenolic closed cells foams were studied using the hot wire technique, adapted for polymeric materials. Results of other properties-for instance, compression strength, Shore D hardness, closed cells content-are also reported for both foams. The thermal conductivity analyses data showed that the phenolic and lignophenolic thermosets have nearly the same behavior, demonstrating the presence of lignin does not affect this property. Thermal conductivity data obtained for closed cells, phenolic and lignophenolic foams, also showed that, in this case, the presence of lignin does not alter this property in a significant way, that is both foams can be used as thermal insulator materials. Regarding the mechanical properties and others, the data obtained showed that the partial replacement of phenol by lignin was extremely advantageous, because, it increases the compression strength and inserted the lignophenolic foam in the structural foam class.