Studies on the Phase Separation of a Polyetherimide Modified Epoxy Resin. VI. Effect of Surface Energy on Reaction‐Induced Phase Separation of Epoxy Resin Modified with Polyetherimide

Abstract

The effect of surface energy on the phase separation of polyetherimide modified epoxy systems is studied by time‐resolved light scattering (TRLS), differential scanning calorimeter (DSC), scanning electron microscopy (SEM), and rheometer. Scanning electron microscopy shows that phase separation of F‐blend system goes further and finally, smaller epoxy‐rich particles and thicker polyetherimide (PEI)‐rich layers are generated. Differential scanning calorimeter and TRLS experiments indicate that the F‐PIP/Epoxy blend has a lower curing rate and phase separation rate than the P‐PIP/Epoxy blend. Rheological behavior displays that the viscosity of F‐PIP/Epoxy blend is lower than that of P‐PIP/Epoxy blend. By studying the properties of different PIP surface the F‐PIP and P‐PIP give different surface energy and it could be concluded that kinetics is a control factor in the phase separation of the two blends due to their difference of surface energy of PEI chain.

Keywords:

• Epoxy resin
• Polyetherimide
• Surface energy
• Phase separation

Acknowledgment

Project 50043011 was supported by the National Science Foundation of China.