Mechanical and Flame Retardant Properties of Phenolic Foam Modified with polyethyleneglycol as Toughening Agent

Polyethyleneglycol (PEG) was used as a as a toughening agent and mixed with the phenolic resin to prepare the foam. The effects of polyethyleneglycol on mechanical and flame retardant properties of phenolic foam were studied by compressive strength, tensile strength, heat stability, scanning electron microscopy (SEM), UL-94 and limited oxygen index (LOI). The apparent density and SEM results showed that the addition of PEG can decrease the apparent density of phenolic foam. The compressive, impact test results showed that the incorporation of PEG into PF dramatically improved the compressive strength, impact strength, indicating the excellent toughening effect of PEG. The LOI of PEG modified phenolic foams remained a high value and the UL-94 results showed all samples can pass V-0 rating, indicating the modified foams still had good flame retardance. The thermal properties of the foams were investigated by thermogravimetric analysis.