Catalytic Activity of Oxidized Carbon Black and Graphene Oxide for the Crosslinking of Epoxy Resins

Abstract

This article compares the catalytic activities of oxidized carbon black (oCB) and graphene oxide (eGO) samples on the kinetics of a reaction of diglycidyl ether of bisphenol A (DGEBA) with a diamine, leading to crosslinked insoluble networks. The study is mainly conducted by rheometry and Differential Scanning Calorimetry (DSC). Following the same oxidation procedure, CB samples are more efficiently oxidized than graphite samples. For instance, CB and graphite samples with high specific surface areas (151 and 308 m 2 /g), as oxidized by the Hummers' method, exhibit O/C wt/wt ratios of 0.91 and 0.62, respectively. Due to the higher oxidation levels, these oCB samples exhibit a higher catalytic activity toward the curing of epoxy resins than fully exfoliated graphene oxide.

Challenges of the Usual Graphical Methods Used to Characterize Phase Change Materials by Differential Scanning Calorimetry

“…To apply our results to composite materials (see for example [18]), it must first be checked that cell-size samples tested in the calorimeter can be considered as homogeneous. Secondly, the important information will be given during the change of state of the polymer and not in the "sensible" temperature range where the measurement of the specific heat is less discriminating.…”

Rheological Properties and Thermal Conductivity of Epoxy Resins Filled with a Mixture of Alumina and Boron Nitride

“…For this purpose, many types of inorganic or metallic fillers with high thermal conductivity, low thermal expansion coefficient, and low electrical conductivity, such as silica [5,6,7,8,9,10], alumina (Al 2 O 3 ) [11,12,13,14], aluminum nitride [15,16,17,18], and hexagonal boron nitride (BN) [19,20,21,22,23,24,25] were studied. Model predictions of and experimental studies on the effects of graphite or graphene oxide on EP resins were also reported [26,27,28].…”

Graphene‐Based Carbocatalysts for Thermoset Polymers and for Diastereoselective and Enantioselective Organic Synthesis

“…It is presently well established that graphene oxide is an efficient catalyst for the cross‐linking of industrially relevant thermosets for compositions typical of reinforcing fillers (1–3 wt %). In particular, the influence of different graphite‐based nanofillers (HSAG, GO, but also oxidized carbon black) on the amine cross‐linking of epoxy resins has been deeply studied . Studies on the cross‐linking kinetics of a commercial epoxide resin (diglycidyl ether of bisphenol A, DGEBA, Scheme ) with different diamines have revealed remarkable catalytic activity for graphene oxide and oxidized carbon black but poor catalytic activity for HSAG.…”

“…[23][24][25][26][27][28][29] The third section is devoted to the dual role of graphene-based materials,t hat is, as ac atalysta nd as a filler,f or thermoset polymers. [29][30][31][32][33][34][35] The fourth sectiond escribes reactions that are catalyzed not only by graphene oxide (being acidic and rich of functional groups) but also by HSAG.The observed behavior is rationalized by the predominant catalytic role of p stacking of the aromatic substrates with the graphitic planes. [23,26] This feature is also determinantf or unexpected diastereoselective and enantioselective catalytic behaviors.…”

“…In particular, it is shown that the main drawbacks of carbocatalysts, that is, high catalyst loading (in weight amounts close to those of the reactants) and generally poor selectivity, can often be removed by operating under solvent‐free conditions . The third section is devoted to the dual role of graphene‐based materials, that is, as a catalyst and as a filler, for thermoset polymers . The fourth section describes reactions that are catalyzed not only by graphene oxide (being acidic and rich of functional groups) but also by HSAG.…”