Toughness and Reinforcement of Diglycidyl Ether of Bisphenol-A by Hyperbranched Poly(trimellitic anhydride-butanediol glycol) Ester Epoxy Resin

Hyperbranched epoxy resin shows best comprehensive performance in epoxy resin system and is considered as a kind of toughness and reinforcement additive. This article reports on the use of novel hyperbranched poly(trimellitic anhydride-butanediol glycol) ester epoxy resin (HTBE) prepared by us as a functional additive to an epoxy amine resin system. The effect of molecular weight and content of the HTBE on the performance of the diglycidyl ether of bisphenol-A (DGEBA)/HTBE hybrid resin are discussed in detail, and their performance has maximum with the increase of content and molecular weight of HTBE. The impact strength and fracture toughness of the hybrid resin containing 9 wt% second generation of HTBE are 48.2 kJ/m(2) and 2.71 MPa m(1/2), and which almost are 2.77 and 1.5 times of DGEBA performance respectively. Furthermore, the tensile and flexural strength can also be enhanced about 17%. The fracture surface micrograph of hybrid resin shows no microphase separation of the HTBE/DGEBA blends that facilitates an enhanced interaction to achieve excellent toughness and strength enhancement of the cured systems by scanning electron microscope (SEM). A novel situ reinforcing and toughening mechanism and model are discovered and confirmed by SEM, molecular simulation, and dynamic mechanical thermal analysis technology. POLYM. COMPOS., 30:918-925, 2009. (C) 2008 Society of Plastics Engineers