The effect of epoxidized polybutadiene-b-polystyrene (EBS) on the reaction induced phase separation behavior of poly(phenylene oxide) (PPO)/diglycidyl ether of bis phenol A (DGEBA)/ 4,4’-methylene-bis(2,6-dimethylaniline) (DIM-DDM) blends was investigated by scanning electron microscopy (SEM), optical microscopy (OM) and time resolved light scattering (TRLS). The experimental results indicated that EBS had a restriction effect on the reaction induced phase separation. The range of PPO content in the blends became wider with increasing of EBS content when bicontinuous phase structures were obtained. In addition, the phase sizes of bicontinuous phase structures were diminished with increasing of EBS content at the same PPO content to DGEBA.

Key words: epoxidized polybutadiene-b-polystyrene, poly(phenylene oxide), epoxy resin, phase separation