Prakaipetch Punchaipetch(1), Veronica Ambrogi(1)(2), Marta Giamberini(2), Witold Brostow (1), Cosimo Carfagna(2), Mandika Anne D'Souza(1)

(1) Department of Materials Science and Chemistry, University of North Texas, Denton, TX 76203-5310, USA; brostow@unt.edu
(2) Department of Materials and Production Engineering, University of Naples Frederico II, Pizzale Techio 80, 80125 Naples, Italy

ABSTRACT

The effect of coreaction diglycidyl ether of bisphenol F (DGEBP-F) with diglycidyl ether of 4,4' - dihydroxybiphenol (DGE-DHBP) on mechanical properties is investigated.  DGE-DHBP shows a liquid crystal (LC) transition upon curing.  Tensile, impact and fracture toughness test results are evaluated.  Dynamic mechanical analysis is conducted to determine the effect of the DGE-DHBP component.  Scanning electron microscopy of fracture surfaces shows changes in failure mechanism compared to the pure components.  The results indicate that the mechanical properties of these blended samples are significantly improved at 10-20% by weight DGE-DHBP.  This is a consequence of the rigidity of the LC component which thus provides the reinforcement. 

Keywords: Epoxy; Polymer liquid crystals; Fracture toughness