In this paper, the effect of modified nanosilica as a reinforcement agent on the performance of epoxy resin using tetrabutyl titanate (TBuT) hardener were investigated. Morphology of the epoxy/modified silica composites was determined by Scanning Electron Microscopy (SEM) method. | Vietnam Journal of Science and Technology 56 (2A) (2018) 133-140 EPOXY/TITANATE MODIFIED NANOSILICA COMPOSITES: MORPHOLOGY, MECHANICAL PROPERTIES AND FRACTURE TOUGHNESS Ho Ngoc Minh1, 3,*, Tran Thi Thanh Van2, Nguyen Thuy Chinh2, Thai Hoang2, 3,* 1 Institute of Chemistry and Material, Hoang Sam Street, Cau Giay, Ha Noi 2 Institute for Tropical Technology, VAST, 18 Hoang Quoc Viet Road, Cau Giay, Ha Noi 3 Graduate University of Science and Technology, VAST, 18 Hoang Quoc Vie, Cau Giay, Ha Noi * Emails: minhquang8188@ and hoangth@ Received: 02 April 2018; Accepted for publication: 13 May 2018 ABSTRACT In this paper, the effect of modified nanosilica as a reinforcement agent on the performance of epoxy resin using tetrabutyl titanate (TBuT) hardener were investigated. Morphology of the epoxy/modified silica composites was determined by Scanning Electron Microscopy (SEM) method. Impact strength and flexural strength of the composites were measured by Charpy impact test and three-point bending test mode methods, respectively. Fracture toughness and fracture energy were calculated according to pre-cracked, single edge notched method with specimens in three-point bending geometry and suitable equations. The mechanical properties and fracture toughness of composites were significantly enhanced with loading nanosilica content to 5 wt.%. Keywords: epoxy, modified nanosilica, nanocomposite, tetrabutyl titanate (TBuT) hardener, fracture toughness. 1. INTRODUCTION Composite materials based on polymers and nanosized additives can provide engineering applications by some advantages of nanosized additives such as high stiffness, strength, wear resistance, and fracture toughness [1-2]. Thanks to high mechanical performance and high adhesive strength, epoxy resins have been commonly applied in aerospace, construction, structural adhesive and so on. However, cured epoxy systems have one main drawback: considerable brittleness, which shows poor fracture .
