Design of Intrinsically Flame-Retardant Vanillin-Based Epoxy Resin for Thermal-Conductive Epoxy/Graphene Aerogel Composites

Abstract

Vanillin, as a lignin-derived mono-aromatic compound, has attracted increasing attention due to its special role as an intermediate for the synthesis of different biobased polymers. Herein, intrinsically flame-retardant and thermalconductive vanillin-based epoxy/graphene aerogel (GA) composites were designed. First, a bifunctional phenol intermediate (DN-bp) was synthesized by coupling vanillin with 4, 4′-diaminodiphenylmethane and DOPO, and the epoxy monomer (MEP) was obtained by the epoxidation reaction with DN-bp and epichlorohydrin. Then, various amounts of MEP and diglycidyl ether of bisphenol A (DER) were mixed and cured. Interestingly, the flexural strength and modulus were greatly enhanced from 72.8 MPa and 1.3 GPa to 90.3 MPa and 2.8 GPa, respectively, at 30 wt % MEP, due to the rigidity of MEP and strong intermolecular N−H hydrogen bonding interactions. Meanwhile, the cured epoxy achieved a UL-94 V0 rating with a low P content of 1.06%. The flame-retardant vanillin-based epoxy was then impregnated into the thermal conductive 3D GA networks. The obtained epoxy/graphene composite showed excellent flame retardancy and thermal conductivity [λ = 0.592 W/(m•K)] with only 0.5 wt % graphene in the system. Based on these results, we believe that this work would represent a novel solution for the preparation of high-performance biobased flameretardant multipurpose epoxies.

Enhanced ultra violet resistance of epoxy nanocomposites filled with liquid-like graphene oxide/silicon dioxide nanofluid

“…To overcome these limitations, various UV resistant nano materials such as TiO 2 , 7 SiO 2 , 8 carbon nanotubes (CNTs) 9 and graphene 10,11 were added into the epoxy resins. In particular, GO has many superior physical and chemical properties, owing to its single-layer planar membrane made of carbon atoms with sp 2 hybridized orbitals.…”

Characteristics and Application of Eugenol in the Production of Epoxy and Thermosetting Resin Composites: A Review

“…Bio-based tannic acid epoxy produced by modification of tannic acid was described by Borah et al [ 23 ]. Likewise, vanillin-based epoxy oligomers are an important group of materials for the synthesis of biological thermosetting epoxy resins [ 24 , 25 , 26 , 27 ]. Dai et al describe the use of genistein, which contains an isoflavone structure, as the basis for the production of a sustainable epoxy resin [ 28 ].…”

Hierarchically Porous Graphene Aerogels with Abundant Oxygenated Groups for High-Energy-Density Surpercapacitors

“…Graphene is a two-dimensional (2D) carbonaceous nanomaterial with sp 2 -hybridized carbon atoms arranged in a honeycomb lattice and has attracted tremendous attention as a result of its high intrinsic carrier mobility (200 000 cm 2 V –1 s –1 ), excellent thermal conductivity (5000 W m –1 K –1 ), high optical transmittance (97.7%), large specific surface area (SSA, 2630 cm 2 g –1 ), superior mechanical strength, etc. − Considerable effort has been devoted to the assembly of graphene-based macroforms to fully utilize the above-mentioned remarkable properties of individual sheets in macroscopic scale. Thus far, a diversity of graphene-based macroforms, including fibers, , membranes, , and hydrogels and aerogels, , have been fabricated, and their potential applications have been extensively explored. , Among these macroforms, graphene-based aerogels characterized by low density, large SSA, high porosity, and low thermal conductivity − show promising applications in the fields of energy storage, sensors, catalysis, thermal insulators, etc.…”

“…1−3 Considerable effort has been devoted to the assembly of graphene-based macroforms to fully utilize the abovementioned remarkable properties of individual sheets in macroscopic scale. Thus far, a diversity of graphene-based macroforms, including fibers, 4,5 membranes, 6,7 and hydrogels and aerogels, 8,9 have been fabricated, and their potential applications have been extensively explored. 10,11 Among these macroforms, graphene-based aerogels characterized by low density, large SSA, high porosity, and low thermal conductivity 12−14 show promising applications in the fields of energy storage, sensors, catalysis, thermal insulators, etc.…”