| Abstract: | The objective of this study was to compare the mechanical properties between epoxy composites cured by thermal heating and microwave heating. Epoxy‐anhydride resins reinforced with glass fiber were cured in a domestic microwave oven and in a thermal oven. Hardening agents included methyl tetrahydrophthalic anhydride and methyl hexahydrophthalic anhydride. Microwave curing was carried out at various conditions, including 1‐, 2‐, and 3‐step heating cycle, whereby each cycle employed different power level and time. Mechanical properties were tested according to ASTM standards. It is found that the microwave‐cured composites produced mechanical properties as good as the thermally cured composites. The 2‐ and 3‐step heating cycle used in the microwave curing process produced better mechanical properties higher than those obtained from the microwaved 1‐step and thermally curing process. This is attributed to the slow increase in temperature during the beginning of the microwave curing process whereby the very low power level was applied in the first cycle of the multistep heating process. This affected the slower rate of viscosity increment, resulting in better wettability of the glass fiber with enhanced interfacial adhesion between the fibers and the resins. The viscosity of resins affected the homogeneity of the crosslinked structure. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1059–1070, 2006 |
