scholarly journals New Eco-Friendly Synthesized Thermosets from Isoeugenol-Based Epoxy Resins

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 229 ◽  
Author(s):  
Quentin Ruiz ◽  
Sylvie Pourchet ◽  
Vincent Placet ◽  
Laurent Plasseraud ◽  
Gilles Boni

Epoxy resin plays a key role in composite matrices and DGEBA is the major precursor used. With the aim of favouring the use of bio resources, epoxy resins can be prepared from lignin. In particular, diglycidyl ether of isoeugenol derivatives are good candidates for the replacement of DGEBA. This article presents an effective and eco-friendly way to prepare epoxy resin derived from isoeugenol (BioIgenox), making its upscale possible. BioIgenox has been totally characterized by NMR, FTIR, MS and elemental analyses. Curing of BioIgenox and camphoric anhydride with varying epoxide function/anhydride molar ratios has allowed determining an optimum ratio near 1/0.9 based on DMA and DSC analyses and swelling behaviours. This thermoset exhibits a Tg measured by DMA of 165 °C, a tensile storage modulus at 40 °C of 2.2 GPa and mean 3-point bending stiffness, strength and strain at failure of 3.2 GPa, 120 MPa and 6.6%, respectively. Transposed to BioIgenox/hexahydrophtalic anhydride, this optimized formulation gives a thermoset with a Tg determined by DMA of 140 °C and a storage modulus at 40 °C of 2.6 GPa. The thermal and mechanical properties of these two thermosets are consistent with their use as matrices for structural or semi-structural composites.

RSC Advances ◽  
2020 ◽  
Vol 10 (68) ◽  
pp. 41954-41966 ◽  
Author(s):  
Samuel Malburet ◽  
Chiara Di Mauro ◽  
Camilla Noè ◽  
Alice Mija ◽  
Marco Sangermano ◽  
...  

Beyond the need to find a non-toxic alternative to DiGlycidyl Ether of Bisphenol-A (DGEBA), the serious subject of non-epichlorohydrin epoxy resins production remains a crucial challenge that must be solved for the next epoxy resin generations.


2011 ◽  
Vol 236-238 ◽  
pp. 116-119
Author(s):  
Wen Ming Zhang ◽  
Yu Cang Zhang ◽  
De Feng Zhao

The liquefied corn barn-based epoxy resin (LCBER) was synthesised through the glycidyl etherification reaction from liquefied corn barn (LCB) had having groups of bound phenol and epichlorohydrine under alkali conditions. The average molecular weights of LCBER in various reaction conditions were examined. The extreme high molecular weight portion of LCBER-30 was obtained using LCB at 30 min as raw materials. The epoxy functionality of LCBER was controlled by the amount of bound phenol in LCB. LCBER was cured with polyamide-650 (PA-650) and the thermal and mechanical properties were evaluated. Comparing to the petroleum-based bisphenol-A type epoxy resin (DGEBA), LCBER presented higher adhesive shear strength and good thermal stability. These suggested that LCBER would be more suitable to glue biomass materials.


2012 ◽  
Vol 476-478 ◽  
pp. 665-669 ◽  
Author(s):  
Li Yang ◽  
Miao Yin ◽  
Xiu Yun Li ◽  
Han Bing Ma

In this paper, a type of nanoporous polyhedral oligomeric silisesquioxanes (POSS) containing eight functional groups have been synthesized and mixed with diglycidyl ether of bisphenol A (DGEBA) to form epoxy resin networks with nanostructures. The cured octa(aminophenyl) silsesquioxane (1c-POSS) and DGEBA system inherently possesses higher thermal stability and higher char yield than the control epoxy resins. Furthermore, the dielectric constant of the 1c-POSS/DGEBA material (4.36) is substantially lower than that of the neat epoxy resins (4.64) as a consequence the presence of nanoporous POSS cubes in the epoxy matrix.


2017 ◽  
Vol 37 (2) ◽  
pp. 185-196 ◽  
Author(s):  
Hamid Reza Salehi ◽  
Manouchehr Salehi

Abstract In this work, the effects of nano titania are investigated on mechanical, creep, and viscoelastic behaviors of epoxy resin. For this purpose, 0.25, 0.5, and 1 vol.% of TiO2 nanoparticles were mixed with thermoset epoxy resin by mechanical and ultrasonic homogenizers and then the tensile, creep, and DMTA test samples were fabricated. The results of tensile tests show that the addition of TiO2 nanopowder slightly increased the strength and Young’s modulus of epoxy resin. However, the ultimate tensile strain or the rupture strain of nanocomposites is decreased. In addition, to understand the viscoelastic behavior of nanocomposites, the DMTA and tensile creep tests have been done. Tensile creep test has been done by DMTA and universal test machine. Both results confirmed that the creep resistance of nanocomposites has extensively improved by adding the titania nanoparticles. Variations of storage modulus, loss modulus, and tan (δ) by adding TiO2 nanopowder were examined in two modes of bending and tension. Storage and loss moduli of nanocomposite are considerably increased in all the states, but the storage modulus was more sensitive to TiO2 loading intensity. Thus, test results showed that introduction of TiO2 in the epoxy resin leads to the improvement of mechanical, creep resistance, and viscoelastic properties of nanocomposites. Due to the wide applications of epoxy resins in engineering devices, this method of reinforcement can be practical and useful to overcome some limitations of epoxy resins.


2015 ◽  
Vol 1110 ◽  
pp. 69-72
Author(s):  
Fu Ke Wang ◽  
Chao Bin He

The dispersion and exfoliation of graphene oxides in polymer matrix remains a challenge for graphene oxides based epoxy nanocomposites fabrication. In the present paper, we reported a simple and facile solvent exchange technique to successfully transfer graphene oxides (GOs) from aqueous solution to ethanol. In addition, we found that GO dispersion in epoxy resins was affected by the curing agents. Good dispersion of GOs in epoxy resin together with enhanced thermal and mechanical properties were observed when epoxy was cured with aliphatic curing agents. For aromatic curing agent, high loading of GOs leaded to GOs aggregation, but well dispersed GOs was observed at low loading of GOs. Especially, a 12 °C increase of glass transition temperature of the epoxy resin was observed with only 0.1 wt% GOs was added to the epoxy resin.


2021 ◽  
Vol 56 (5) ◽  
pp. 179-185
Author(s):  
Omar A. Amin ◽  
S. A. Hassan ◽  
M. A. Sadek ◽  
M. A. Radwan ◽  
Hany A. Elazab

Epoxy resins are thermoset polymers that consist of epoxide groups in their molecular structure. It shows many attractive characteristics like strong adhesion, excellent mechanical strength, low shrinkage, excellent insulator, excellent chemical stability for acidic and basic environments, and microbial resistance due to the presence of hydroxyl groups and ether bonds and its three-dimensional structure. Many of these characteristics can be modified by adding strong bindings in the polymeric chain to give more improved characteristics. This research aims to prepare a composite material using epoxy resin and different types of fillers to achieve resistance to high kinetic energy impact. Experimental work is focused on preparing cured epoxy resin samples by using diglycidyl ether of bisphenol A (DGEBA) resin with tertiary amine as a hardener. In order to obtain different samples with different properties, we add different types of fillers, then mechanical tests are used to measure the mechanical properties of the samples. The results have proved that fiberglass is the best filler added to epoxy resins to improve its mechanical properties.


Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1354 ◽  
Author(s):  
Diego Lascano ◽  
Luis Quiles-Carrillo ◽  
Sergio Torres-Giner ◽  
Teodomiro Boronat ◽  
Nestor Montanes

This research deals with the influence of different curing and post-curing temperatures on the mechanical and thermomechanical properties as well as the gel time of an epoxy resin prepared by the reaction of diglycidyl ether of bisphenol A (DGEBA) with an amine hardener and a reactive diluent derived from plants at 31 wt %. The highest performance was obtained for the resins cured at moderate-to-high temperatures, that is, 80 ° C and 90 ° C , which additionally showed a significant reduction in the gel time. This effect was ascribed to the formation of a stronger polymer network by an extended cross-linking process of the polymer chains during the resin manufacturing. Furthermore, post-curing at either 125 ° C   or 150 ° C yielded thermosets with higher mechanical strength and, more interestingly, improved toughness, particularly for the samples previously cured at moderate temperatures. In particular, the partially bio-based epoxy resin cured at 80 ° C and post-cured at 150 ° C for 1 h and 30 min, respectively, showed the most balanced performance due to the formation of a more homogeneous cross-linked structure.


Molecules ◽  
2019 ◽  
Vol 24 (23) ◽  
pp. 4305 ◽  
Author(s):  
Valeriia Karaseva ◽  
Anne Bergeret ◽  
Clément Lacoste ◽  
Hélène Fulcrand ◽  
Laurent Ferry

The aim of this work was an investigation of the ability of gallic (GA) and ellagic (EA) acids, which are phenolic compounds encountered in various plants, to act as flame retardants (FRs) for epoxy resins. In order to improve their fireproofing properties, GA and EA were treated with boric acid (to obtain gallic acid derivatives (GAD) and ellagic acid derivatives (EAD)) to introduce borate ester moieties. Thermogravimetric analysis (TGA) highlighted the good charring ability of GA and EA, which was enhanced by boration. The grafting of borate groups was also shown to increase the thermal stability of GA and EA that goes up respectively from 269 to 528 °C and from 496 to 628 °C. The phenolic-based components were then incorporated into an epoxy resin formulated from diglycidyl ether of bisphenol A (DGEBA) and isophorone diamine (IPDA) (72, 18, and 10 wt.% of DGEBA, IPDA, and GA or EA, respectively). According to differential scanning calorimetry (DSC), the glass transition temperature (Tg) of the thermosets was decreased. Its values ranged from 137 up to 108 °C after adding the phenolic-based components. A cone calorimeter was used to evaluate the burning behavior of the formulated thermosets. A significant reduction of the peak of heat release rate (pHRR) for combustion was detected. Indeed, with 10 wt.% of GA and EA, pHRR was reduced by 12 and 44%, respectively, compared to that for neat epoxy resin. GAD and EAD also induced the decrease of pHRR values by 65 and 33%, respectively. In addition, a barrier effect was observed for the resin containing GAD. These results show the important influence of the biobased phenolic compounds and their boron derivatives on the fire behavior of a partially biobased epoxy resin.


2011 ◽  
Vol 284-286 ◽  
pp. 365-368 ◽  
Author(s):  
Jing Zhu ◽  
Yong Wu ◽  
Lei Zhao ◽  
Hong Liang Wei ◽  
Hui Juan Chu ◽  
...  

Hexakis-(4-aminophenoxy)-cyclotriphosphazene (PN-NH2) was synthesized through nucleophilic substitution of the chloride atoms of hexachlorocyclotriphosphazene (HCCP) and reduction of the nitro group, and its chemical structure was characterized. As a curing agents for commercial epoxy resin Diglycidyl ether of bisphenol-A (DGEBA) PN-NH2 was compared with conventional curing agents 4,4-diaminodiphenylsulfone(DDS) and 4,4-diaminodiphenylmethane (DDM). The thermal properties and thermal degradation behaviors of these thermosetted resins were investigated by using thermogravimetric analysis (TGA). TGA studies demonstrated that the thermal properties of the PN-NH2-containing cured epoxy resin were higher than those of others. The phosphorus-nitrogen containing curing agent can result in a great improvement of the flame retardance for their thermosetted epoxy resins.


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