Toughening of epoxy resins by modification with aromatic polyesters

摘要

AbstractAromatic polyesters, prepared by the reaction of phthalic or isophthalic acids and α,ω‐alkanediols, were used to reduce the brittleness of bisphenol‐A diglycidyl ether epoxy resin cured with methyl hexahydrophthalic anhydride. These polyesters were effective as modifiers for toughening of the epoxy resin system. The most suitable composition for modification of the epoxy resins was inclusion of 20 wt of poly(ethylene phthalate) (MW 7200), which resulted in a 150 increase in the fracture toughness (KIC) of the cured resin at no expense of its mechanical properties. The effectiveness of poly(alkylene phthalate)s as modifiers decreased with increasing the chain length of alkylene units. The toughening mechanism was discussed based on the morphological and dynamic mechanical behaviors of the modified epoxy resin s