Investigation of cure kinetics in epoxy/multiwalled carbon nanotube nanocomposites

Abstract

With the increased interest in thermoset resin nanocomposites, it is important to understand the effects of the material on nanoscale characteristics. In this study, a curing reaction of an epoxy resin, which contained 0.25, 0.50, or 1.00 wt % of multiwalled carbon nanotubes (MWCNTs), at different heating rates was monitored by differential scanning calorimetry; cure kinetics were also evaluated to establish a relationship between crosslinking (network formation) and mechanical properties. MWCNT concentrations above 0.25 wt % favored crosslinking formation and decreased the activation energy (Ea) in the curing reaction. Examination of the kinetic mechanism suggests that the MWCNT locally restricted the spatial volume and favored the formation of nodular morphology in the resin, especially for high MWCNT concentrations. The MWCNT exhibited some entanglement in the matrix, which hindered a more pronounced effect on the mechanical properties. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39857.

Effect of Nanoclay on the Mechanical, Thermal, and Water Absorption Properties of an UP-toughened Epoxy Network

“…Figure 7 illustrates how the peak temperature increases with the heating rate. Similar results were also reported in the literature [68,69,72,73], showing that the peak temperature (T p ) increased with increasing heating rates (5, 10, 15 and 20 o C/min). On the other hand, the enthalpy of the Epoxy/UP system decreased when C30B clay was added at different heating rates, as shown in Figure 8.…”

Functionalization of carbon nanotubes with (3‐glycidyloxypropyl)‐trimethoxysilane: Effect of wrapping on epoxy matrix nanocomposites

“…The low thermal stability of the functionalized MWCNT with respect to pristine can be explained by the formation of defects along the MWCNT walls. Such defects are a result of functionalization, wherein the conjugated sp structure of MWCNT is changed by the “graft” functional groups (in this case, COOH, OH, lactone, and siloxane groups) to a sp 3 hybridization structure . It is also observed in Figure that the MWCNT‐COOH sample shows a significantly lower T max (temperature of the maximum in the mass loss rate) than MWCNT‐GLYMO samples.…”

“…Multiwalled carbon nanotubes (MWCNT) are often investigated as reinforcement in polymer matrices, due to their outstanding mechanical and electrical properties. [1][2][3][4][5] Actually, the incorporation of small amounts of carbon nanotubes in a polymer matrix, usually between 0.1 and 5 wt %, can potentially provide structural materials with higher modulus and mechanical strength, as well as improvements in thermal and electrical performances. [2][3][4][5][6] These nanocomposites can find applications in automotive, aerospace, marine, defense, energy, and electronics industries.…”

“…[1][2][3][4][5] Actually, the incorporation of small amounts of carbon nanotubes in a polymer matrix, usually between 0.1 and 5 wt %, can potentially provide structural materials with higher modulus and mechanical strength, as well as improvements in thermal and electrical performances. [2][3][4][5][6] These nanocomposites can find applications in automotive, aerospace, marine, defense, energy, and electronics industries. 1,3,6 On the other hand, it is known that the intermolecular interactions (mainly van der Waals) are responsible for the formation of MWCNT agglomerates.…”

Fabrication and evaluation of acrylated epoxidized castor oil‐toughened diglycidyl ether of bisphenol A nanocomposites

“…The characteristic signals appearing at 0.0053-0.0057 mL/L of CO are associated with C¼C bonds, and they convert to an oxirane ring at 0.0028-0.0032 mL/L of ECO. [47][48][49][50] The residual epoxide group appeared in AECO spectra at 820 cm À1 . [43][44][45] The AECO spectra also had peaks at 0.0053-0.0056 mL/L (-CH¼CH-) and 0.003-0.0032 mL/L (epoxide proton) which indicate an incomplete acrylation reaction.…”