Microstructure and performance of block copolymer modified epoxy coatings

Engineering superior toughness in commercially viable block copolymer modified epoxy resin

“…Following this approach, Bates and many coworkers have extensively dealt with epoxy‐philic poly(ethylene oxide) (PEO) and other polar block based copolymers. Several other groups, including Zheng and coworkers, have also developed a reaction‐induced microphase separation approach, where a linear or star‐shaped block copolymer containing a block that is initially miscible with the epoxy precursor, generally displaying an upper critical solution temperature (USCT), microphase separates during curing leading to various microstructures, for instance, a “raspberry‐like” and “onion‐like” morphologies .…”

Synergic effects of poly(vinyl butyral) on toughening epoxies by nanostructured rubbers

“…Remarkably, G Ic reaches 2015 J/m 2 at 20 phr LR1 but 1432 J/m 2 at 20 phr LR2, respectively, in these ternary blends containing 20 phr PVB. The synergic effects of the PVB on rubber toughening of the epoxy resin are unusual in terms of the magnitude of the improvement in facture toughness of the blends, as typically the improvement in fracture toughness does not exceed 10 fold [88] in conventional rubber toughening of epoxies. Here, simultaneous application of both the PVB and the liquid rubber leads to an improvement in fracture toughness by more than 20 fold for LR1 and 14 fold for LR2, indicating not only the important role of the rubber phase but also the essential role of the PVB in toughening the epoxy.…”

“…The nanodomains were able to preserve themselves after the curing of epoxy resins. It has been shown that a low (typically < 5 wt%) concentration of the block copolymers could increase the fracture toughness of epoxies by 10e20 fold [88]. While significant progress has been made in toughening epoxy resins using block copolymers, detailed toughening mechanisms with the exception of nanocavitation still remain elusive [10].…”

“…Compared with coreeshell particles and amphiphilic block copolymers, liquid rubbers have advantages such as a lower cost and broader availability; however, they typically phase separate on the micrometer (not nanometer) scale during the curing of epoxies, and generally the rubber particle size is difficult to predict as various factors contribute to the development of rubber particles [2,3,5,6,8,11,88]. In addition, reactive liquid rubbers are known not to form nanodomains as small as amphiphilic block copolymers do.…”

Poly(ether ether ketone)‐bischromenes: Synthesis, characterization, and influence on thermal, mechanical, and thermo mechanical properties of epoxy resin

“…2 These shortcomings can be alleviated by blending with various toughening agents such as thermoplastics or elastomers. 3 Thermoplastic polymers generally employed to toughen epoxy resins include functionalized poly(ether sulfone), polyester, [4][5][6][7][8] poly(ether imide), [9][10][11] polyimide, 12 polysulfone, 13,14 syndiotactic polystyrene, 15 diblock copolymers such as poly(ethylene-propylene)b-(polyethylene oxide), 16 poly(ether ether ketone) (PEEK). [17][18][19][20][21][22] Mechanical properties of the epoxy-thermoplastic blends are better governed by their miscibility 19,23 characteristics with the epoxy resins.…”