Toughening by nanostructure

Abstract

a b s t r a c tBlock copolymer modified epoxy resins have generated significant interest since it was demonstrated that the combination could lead to nanostructured thermosets through self-assembly. Over moderate to high polymer concentration the system behaves as expected for a block copolymer in a solvent selective for one block. Two types of copolymers have been studied: non-reactive and reactive modifiers. Morphologies such as copolymer vesicle and spherical/wormlike micelles can be formed under the appropriate conditions. The enhancement of the modified thermosets' mechanical properties depends on the morphology adopted by the polymers. Besides improving mechanical properties, the morphology was found to also have an effect on the glass transition in the studied systems. In this review we collect the available data on the block copolymers used to fabricate nanostructured epoxy resins and critically appraise the properties reported.

Block copolymer strategies for solar cell technology

“…Although block copolymers have been used as compatibilizing agents extensively across the literature, [186][187][188][189] their application as such in organic solar cells remains limited. This is perhaps somewhat surprising as this is an area where block copolymers appear to have their most beneficial impact in OPV technology.…”

Enhancement of mechanical performance of epoxy/carbon fiber laminate composites using single-walled carbon nanotubes

“…The addition of soft nano-particles (SNP) has demonstrated great potential to improve the mechanical performance of thermosets and their laminates. While several mechanisms have been proposed to explain such improvements, crack-pinning is frequently cited as one of the key enhancement mechanisms [9].I n recent years, rigid nano-particles such as CNT have shown the potential to act as toughening agents for a range of epoxies due to their high aspect ratios and excellent mechanical properties. CNT toughening mechanisms are mainly based on fiber bridging (fiber pull-out and fracture) and are thus different from those of SNP.…”

Role of Cured Epoxy and Block Copolymer Addition in Mechanical and Thermal Properties of Polyethylene

“…Epoxy resins (ER) often present high operating temperatures, are extremely resistant, both mechanically and chemically, and have high stiffness in comparison to thermoplastic materials [1][2] . The thermoset addition as a second phase in a polyolefin provides an opportunity for modifying the thermal and mechanical properties of the matrix, such as stiffness and crystallinity 3 .…”

“…It is well known that smaller sizes in dispersed phase give more interfacial area and thus favor interactions and synergy in the blend 1 . Zhang and Zheng 13 studied crystallization behavior of HDPE in epoxy matrix, with poly(ε-caprolactone)-blockpolyethylene-block-poly(ε-caprolactone) (PCL-b-PE-b-PCL) triblock copolymer as compatibilizer.…”