Nanostructured thermosetting epoxy systems modified with poly(isoprene‐b‐methyl metacrylate) diblock copolymer and polyisoprene‐grafted carbon nanotubes

Abstract

Nanostructured thermosetting composites based on an epoxy matrix modified with poly(isoprene‐b‐methyl methacrylate) (PI‐b‐PMMA) block copolymer were prepared through PI block segregation. Morphological structures were examined by means of atomic microscopy force microscopy. As epoxy/pristine multi‐walled carbon nanotubes (MWCNT) systems were found to present big agglomerations, with a very poor dispersion of the nanofiller, epoxy/PI‐b‐PMMA/MWCNT systems were prepared by using polyisoprene‐grafted carbon nanotubes (PI‐g‐CNT) to enhance compatibility with the matrix and improve dispersion. It was found that the functionalization of MWCNT with grafted polyisoprene was not enough to totally disperse them into the epoxy matrix but an improvement of the dispersion of carbon nanotubes was achieved by nanostructuring epoxy matrix with PI‐b‐PMMA when compared with epoxy/MWCNT composites without nanostructuring. Nevertheless, some agglomerates were still present and the complete dispersion or confinement of nanotubes into desired domains was not achieved. Thermomechanical properties slightly increase with PI‐g‐CNT content for nanostructured samples, whereas for nonnanostructured epoxy/PI‐g‐CNT composites they appeared almost constant and even decreased for the highest nanofiller amount due to the presence of agglomerates. Compression properties slightly decreased with block copolymer content, while remained almost constant with nanofiller amount. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Amphiphilic Block Copolymer Grafted Multiwalled Carbon Nanotube Based Hierarchical Nanohybrids for Effective Epoxy Toughening

“…But some studies have focused on the analysis of mechanical properties of simultaneous addition of MWCNT and TBCP without any chemical modification. But the results were not promising as toughness improvements were obtained at higher filler loadings with the loss of tensile strength. − But in the current study, it is found that with a lower loading (i.e 0.1 wt %) of the graft a toughness improvement of about 367% is obtained without affecting the tensile property as shown in Figure . Table compares the toughness obtained for the current system with the previous studies.…”

High-Energy Dissipation Performance in Epoxy Coatings by the Synergistic Effect of Carbon Nanotube/Block Copolymer Conjugates

“…More recently, the formation of CNT–BCP patchy conjugates by noncovalent functionalization of CNT with polystyrene- b -polyethylene- b -poly­(methyl methacrylate) triblock copolymer was described, and their potential use as reinforcements in polymer blend nanocomposites was suggested . However, articles investigating material properties of epoxy thermosets modified with CNT and BCP are scarce, − and significant improvements on material properties are yet to be achieved. For instance, Martin-Gallego et al reported an increment of ∼15% in the critical stress intensity factor with respect to neat epoxy for an epoxy nanocomposite bearing multiwalled carbon nanotubes (0.25 wt %) and poly­(ethylene oxide)–poly­(propylene oxide)–poly­(ethylene oxide) BCP (10 wt %), while the addition of CNT (0.25 wt %) or BCP (10 wt %) led to increments of ∼13% with the same property compared to neat epoxy.…”