A Novel Method for Preparation of Nanostructured Phenolic Foam Using High Temperature Sol-Gel Polymerization

Nanostructured phenolic foams are obtained by low temperature aqua-sol-gel polymerization of resorcinol and formaldehyde [1]. Low temperature polymerization (longpreparation time) and relatively high cost of resorcinol are main disadvantages of this method [2]. The main reasons for low temperature polymerization are prevention of solvent evaporation and solution blowing (phenolic releases volatiles during cure). To overcome these disadvantages, in this work a novelprocess for high temperature sol-gel polymerization of commercial low cost novolac resin instead of resorcinol monomer was developed and the effects of curing temperature on mechanical properties of prepared foams were investigated.