Mechanical properties and fracture behavior of high‐performance epoxy nanocomposites modified with block polymer and core–shell rubber particles

Abstract

The mechanical properties, thermomechanical properties, and fracture mechanic properties of block-copolymer (BCP), core-shell rubber (CSR) particles, and their hybrids in bulk epoxy/anhydride system were investigated at 23 C. The results show that fracture toughness was increased by more than 268% for 10 wt % BCP, 200% for 12 wt % of CSR particles, and 100% for hybrid systems containing 3 wt % of each, BCP and CSR. The volume content of nanoparticles influences the final morphology and thus influences the tensile properties and fracture toughness of the modified systems. The toughening mechanisms induced by the BCP and CSR particles were identified as (1) localized plastic shear-band yielding around the particles and (2) cavitation of the particles followed by plastic void growth in the epoxy polymer. These mechanisms were modeled using the Hsieh et al. approach and the values of G Ic of the different modified systems were calculated. Excellent agreement was found between the predicted and the experimentally measured fracture energies.

High strength epoxy system modified with soft block copolymer and stiff core-shell rubber nanoparticles: Morphology, mechanical properties, and fracture mechanisms

“…However, no synergies were observed in the case of BCP-CNT hybrids [28]. Recently some researchers reported hybrid toughening of BCP and CSR nano particles [29,30]. In the present work block co-polymer and core-shell rubber particles with a stiff core were used to toughen a high strength amine cured epoxy system.…”

Synergistic enhancement of mechanical, viscoelastic, transport, thermal, and radiation aging characteristics through chemically bonded interface in nanosilica reinforced EPDM‐CIIR blends

“…If nanosized fillers are incorporated in the matrix, it will take up the free volume within the elastomer blend and imparts a 'tortous' path for solvent permeation. 10,23 The degree of tortuosity is dependent on volume fraction, the shape, and orientation of filler particles. Hence, transport behavior can be used to provide an insight into the morphology of nanocomposites.…”

“…8,9 The improvement in properties of nano-reinforced polymer can be ascribed to the larger interfacial interaction between nanoparticle and matrix, arising from the large specific surface area of the nanofiller. 7,10 Among the nanoparticles, nanosized silicon dioxide, or nanosilica (SiO 2 ), is a good candidate for reinforcement of rubbers owing to their high stability, lower toxicity, and capability to be modified with a range of functional groups. 11 Surface treatments with various modifiers like silane coupling agents have been carried out to enhance filler dispersion and polymer/nanosilica interfacial interactions.…”

Phosphorous-jointed epoxidized soybean oil and rice husk-based silica as the novel additives for improvement mechanical and flame retardant of epoxy resin

“…Thermosetting epoxy resins (EPs) have been widely used as matrices in the fabrication of fiber-filled polymer-based composites owing to their good mechanical properties, high chemical resistance, compatibility with most fibers, processability, and low cost. [5][6][7][8][9][10] However, EPs have a low fracture energy as result of their high crosslinking density after curing. 11,12 This disadvantage limits their application in high-technology areas.…”