اثر نرخ بارگذاری روی چقرمگی شکست اپوکسی اصلاح شده با لاستیک هیبریدی

Fracture Toughness of a Hybrid Rubber Modified

Epoxy. II. Effect of Loading Rate

چقرمگی شکست اپوکسی اصلاح شده با لاستیک هیبریدی.

II. اثر نرخ بارگذاری

ABSTRACT

Effect of loading rate on toughness characteristics of hybrid rubber-modified epoxy was investigated. Epoxy was modified by amine-terminated butadiene acrylonitrile (ATBN) and recycled tire. Samples were tested at various loading rates of 1–1000 mm/min. Fracture toughness measurements revealed synergistic toughening in hybrid system at low loading rates (1–10 mm/min); hybrid system exhibited higher fracture toughness value in comparison with the ATBN-modified resin with same modifier content. However, synergistic toughening was eliminated by increasing the loading rate. At higher loading rates (10–1000), the fracture toughness of hybrid system decreased gradually to the level lower than that of ATBN-modified epoxy. Fractography of the damage zones showed the toughening mechanisms of ATBN-modified system was less affected by increasing the loading rate compared to that of hybrid system.