Structure–property relationships of a bio‐based reactive diluent in a bio‐based epoxy resin

Abstract

ABSTRACT:: The monofunctional glycidyl ether of eugenol (GE) was used as a reactive diluent for the diglycidyl ether of diphenolate n-pentyl ester (DGEDP-Pe). Viscosities of GE and DGEDP-Pe are 25 mPa.s and 11 Pa.s, respectively. Compositions GE/DGEDP-Pe epoxy resins with 5, 10, 15, 20, and 30 wt % GE were analyzed for viscosity reductions and, subsequently, cured with isophorone diamine. The glassy modulus of cured GE/DGEDP-Pe epoxy resins remained between 2000 and 3000 MPa. The glass transition temperature decreased linearly, from 92 8C for neat DGEDP-Pe, with progressively higher loadings of GE to 53 8C at the highest GE loading of 30 wt %. The thermal stability decreased as GE loading increased with a maximum of 30 8C loss in the onset of degradation at 5 wt % mass loss. The role of GE as a reactive diluent is discussed and a range of loadings was determined to be suitable for a vacuum infusion epoxy resin system.

Effect of Reactive and Non-Reactive Diluent on Mechanical Properties of Epoxy Resin

“…The highest viscosity is observed in pure epoxy resin. In addition, the viscosity value obtained by adding the same proportion of benzyl alcohol was measured lower than the addition of diglycidyl ether [9]. The mechanical properties of DGEBA resins (i.e.…”

Recent development on bio‐based thermosetting resins

“…When the phenolic group was integrated by epoxy reactant and the allyl was unchanged, a monofunctional eugenol-based epoxy resin could be obtained, which was used as reactive diluent or additive. [41][42][43] In addition, further modifying one of the functional groups to obtain epoxy precursors with different functions was a feasible method for preparing thermosets with high properties. Wan et al 44 synthesized a difunctional eugenol-based epoxy resin using α,α'-dichloro-p-xylene as phenolic coupling agent, the resultant cured resin has comparable mechanical properties (Young's modulus of 3490 ± 60 MPa) and low flammability (total heat release of 16.3 ± 0.8 kJ/g) to the bisphenol-A epoxy corresponding system.…”

“…Eugenol possesses two reactive functional groups (phenolic hydroxyl and allyl). When the phenolic group was integrated by epoxy reactant and the allyl was unchanged, a monofunctional eugenol‐based epoxy resin could be obtained, which was used as reactive diluent or additive 41–43 . In addition, further modifying one of the functional groups to obtain epoxy precursors with different functions was a feasible method for preparing thermosets with high properties.…”

Eugenol, a developing asset in biobased epoxy resins

“…However, this monomer exhibited a higher viscosity than DGEBA, and low viscosity epoxy monomers are required in order to allow suitable conditions to infuse continuous fibers and prepare composites with fillers. Therefore in a second study 30 the authors interestingly synthesized a mono glycidyl ether of eugenol (GE) (Scheme 4 B) as a reactive diluent for their DGEDP-Pe.…”

“…; B) mono glycidyl ether of eugenol (GE) 30 The glycidylation reaction was performed with an excess of epichlorohydrin (7.5eq) under alkaline conditions (NaOH, 1.1 eq) and under homogenous conditions with 2-propanol at reflux. The resulting product was obtained with yields ranging from 85% to 90%.…”