Fracture Toughness of Phenol Formaldehyde Composites: Pilot Study

A commercial phenol formaldehyde based resole thermosetting resin (Hexion “J2027L”) was filled with ceramic-based fillers (Envirospheres “slg”) to increase its strength and fracture toughness. By testing viscosity, strength, and fracture toughness at a range of filler addition levels, the optimal addition level of SLG was able to be determined in terms of workability, cost, and performance. It was found that the fracture toughness of this resin could be significantly increased through the addition of the slg filler. The results show that composite with 20% by weight of the slg produces the best balance between ease of casting and impact performance.