Design, preparation, and characterization of fast cure epoxy/amine‐functionalized graphene oxide nanocomposites

Abstract

Fast cure epoxy/amine‐functionalized graphene oxide (GO) nanocomposites were designed, prepared, and characterized in this work. The GO nanosheets were functionalized by aliphatic amines having the same structure but different chain length. XPS and FTIR analyses were used to probe chemical structure and elemental surface composition of nanosheets before and after functionalization. Cure kinetics analysis was performed by dynamic differential scanning calorimetry (DSC) on samples containing pristine and functionalized GO to achieve minimum possible hindered cure. Kinetic studies confirmed that addition of pristine GO brings a steric hindrance effect, as signaled by a fall in the onset temperature, exotherm temperature and the total heat of curing reaction. According to isoconversional model, activation energy of cure reaction fell from approximately 80 to slightly over 60 kJ mol−1 as a result of improved dispersion. SEM micrographs provided evidence for good dispersion of GO platelets bearing short‐arm amines; but activation energy in such system was surprisingly higher than that of the one filled with pristine GO. By contrast, network formation in nanocomposites with GO functionalized by long‐arm amine has been facilitated, signifying the dominance of aliphatic amine length over dispersion state. The accelerated/decelerated cure is inferred based on the reactivity of reaction moieties, dispersion state of GO in the epoxy matrix, and cure behavior/kinetics of nanocomposites. The developed fast cure epoxy/GO nanocomposites compete in crosslinking with blank epoxy system. POLYM. COMPOS., 39:E2016–E2027, 2018. © 2017 Society of Plastics Engineers

Friction and mechanical properties of amino-treated graphene-filled epoxy composites: modification conditions and filler content

“…In summary, the oxygenic groups on the rGO-0.5 sheet were reduced compared with GO, while that on the rGO-5 platelets was mostly removed. In the XPS spectrum of rGOs, signals at 399.5 eV corresponding to C-N appeared, 42 which were not observed in the XPS of GO, revealing that the ODA chains were attached to the graphene sheets.…”

A Polyallylamine Anchored Amine‐Rich Laser‐Ablated Graphene Platform for Facile and Highly Selective Electrochemical IgG Biomarker Detection

“…As the binding of biomolecules is a major concern for the immunosensor development, we have introduced polycationic polyallylamine (PAAMI) on the LAG substrate by noncovalent π–π interaction and electrostatic physical absorption 26,27. It provide anchoring sites for the biomolecule, boosts electron transfer rate, as well as increases stability of LAG 28,29. Therefore, the substrates lead to better selectivity and sensitivity, as well as lower limit of detection 30…”

Bulk-Surface Modification of Nanoparticles for Developing Highly-Crosslinked Polymer Nanocomposites

“…Enhancement of properties of thermoset resins via surface modification of nanoparticles has been practiced over the years [ 1 , 2 , 3 ]. Overall, a larger curing widow is the result of nanoparticle incorporation into the thermoset resins, but modification of nanoparticle surface introduced as the solution has hindered or caused incomplete crosslinking [ 4 , 5 , 6 ].…”