Surfactant and Plasticizer Effects on the Physical and Mechanical Properties of Phenolic Foam

ABSTRACT The effects of different surfactant and plasticizer combinations on the physical and mechanical properties of phenolic foams were investigated. Several foams were prepared using ethoxylated castor oil surfactants including Agnique CSO 30, Agnique CSO 20, Emulan EL, Emulan ELH 60, Emulan TO‐2080, and Pluriol A 7509 PH, and organic plasticizers including polyethylene glycol (PEG 600), benzyl butyl phthalate, bis[2‐(2‐butoxyethoxy)ethyl] adipate, DBE‐5 dibasic ester, and dicyclohexyl phthalate. Two foams exhibited superior properties: one prepared with Agnique CSO 30 and PEG (PF1), and another with Emulan EL and PEG (PF11B). These formulations were further optimized by varying surfactant concentrations to study their influence on density, compressive strength, and thermal conductivity. Although both foams showed similar densities, their compressive strengths differed significantly due to variations in surfactant stabilization of blowing agents and resulting cell structures. Additional formulations combining Emulan EL with DBE ester were also developed, one of which achieved high compressive strength with low density and thermal conductivity. Overall, two surfactant‐plasticizer systems: Agnique CSO 30 with PEG 600 (PF1) and Emulan EL with DBE ester (PF11B), demonstrated the most favorable combination of low density, low thermal conductivity, and high compressive strength, highlighting the importance of surfactant selection in tailoring phenolic foam performance.