Preparation and cure kinetics of epoxy with nanodiamond modified with liquid crystalline epoxy

A novel epoxy composite with liquid crystalline epoxy resin modified nanodiamond (ND-LCER) was prepared by grafting diglycidyl ether of 4,4′-bisphenol (DGEBP) monomers onto the surface of acid treated nanodiamond (ND-COOH). Untreated nanodiamond (UND), ND-COOH and ND-LCER were composited with epoxy/4,4′-diamino diphenyl sulfone (DDS) in various weight ratios, respectively. The cure behavior of the prepared composite systems was investigated with dynamic differential scanning calorimetry (DSC) technology at different heating rates. The NDs exhibited acceleration effects on the curing reaction with increase of content amounts, which might attribute to the special structure of the nanodiamond (ND) particles itself and the functional groups of the ND. The modified ND particles showed the lowest activation energy value due to the diminution to the diffusion control process caused by liquid crystalline epoxy resins molecules. The two-parameter (m, n) autocatalytic model of Sestak-Berggren based on the Malek method is in-line with the epoxy/ND composites.