Phase Separation in Poly(Methyl Methacrylate)-Epoxy Blend

Abstract

Diglycidyl ether of bisphenol A (DGEBA) epoxy resin was modified with high molecular weight poly(methyl methacrylate) (PMMA). Morphological variations of a 2 wt% PMMA-modified epoxy mixture were studied by optical microscopy and scanning electron microscopy (SEM). A PMMA-epoxy blend cured at 100°C revealed that a secondary phase morphology was observed in both epoxy and PMMA phases from the early stages of the phase separation process. A morphology consisting of a rough striated continuous phase along with large smooth regions was observed by SEM, confirming the secondary phase separation. The dynamic mechanical thermal analysis showed that the PMMA modification of epoxy at such a low PMMA concentration of 2 wt% has no major influence on the glass transition temperature of the epoxy-rich phase. The PMMA-epoxy blend showed a slight increase in the flexural properties and the fracture toughness.

Keywords:

• epoxy blend
• flexural properties
• fracture toughness
• phase separation
• poly(methyl methacrylate)
• PMMA

Acknowledgement

This work was supported by the Second Stage Brain Korea 21 Program of the Ministry of Education and Human Resources Development of Korea Government.