Abstract: Phenolic resin was modified with epoxidized soybean oil (ESO) and organic-montmorillonite (OMMT) in order to improve its mechanical properties. The grafting of phenolic resin with ESO via etherification resulted in toughening, and the mechanical properties of modified phenolic resin was further enhanced with inorganic nanoparticles. After adding 40 wt% ESO, the impact strength of the phenolic resin was increased by 72 %, bending strength and elongation at break reached 94 MPa and 4.5 %, respectively. By introducing 2 wt%OMMT into the ESO toughened phenolic resin, the impact strength increased by 42.2 %, bending strength tensile strength, and elongation at break reached 111 MPa, 30.8 MPa, and 40 %, respectively.

Key words: phenolic resin, epoxidized soybean oil, montmorillonite, entoughness, mechanical property