The Power of Processing: Creating High Strength Foams from Epoxidized Pine Oil

Abstract

The present work reports on the synthesis of foams from epoxidized pine oil (EPO) with polymethylhydrosiloxane (PMHS) used as a foaming agent. The effect of two different processing methods involving modifications of curing agent and foaming agent addition timings was also analyzed. Resultant foams were characterized via density, mechanical and thermal testing, and microstructure. Foams produced using a modified processing method displayed properties that deviate from the Ashby–Gibson models, resulting in superior compressive strengths over many synthetic and biobased epoxy foams, ranging from 6.1 to 11.3 MPa. The impact of the method on cellular microstructure was also significant, with 20- and 30-fold increase in cell density from the original processing method for the same levels of foaming agent in both the methods. Glass transition temperatures of the foams ranged from 61.8 to 97 °C, higher than those of many foams in their class.