“…PEGDA curing agent was synthesized in three steps starting from PEG according to our previous report. 26 Figure 1.(A) Synthesis reaction of PEGDGE (B) Chemical structures of BADGE, IPDA and PEGDA.…”
Section: Resultsmentioning
confidence: 99%
“…PEG diamine (PEGDA) was prepared from PEG (Sigma-Aldrich with MW¯ of 600 g/mol) according to our previous work. 26 BADGE was obtained from Sigma-Aldrich with an EEW of 170–176 g/eq (EV = 0.57–0.58 mol/100 g) and used as received. PEGDGE was synthesized from PEG according to the literature.…”
Section: Methodsmentioning
confidence: 99%
“…In our recent studies, Jeffamine D-230 and 3-aminopropyltriethoxysilane were used for amine-functionalization of graphene oxide nanoflakes and silica nanospheres, respectively. 23,24 The functionalized nanofillers were then used in polyoxyalkylene-containing binary epoxy-amine systems. Various kinds of polyoxyalkylene segments such as polyoxybuthylene and polyoxyethylene can cause more flexibility in the epoxy thermoset films.…”
Section: Introductionmentioning
confidence: 99%
“…b) shows the structure of other monomers used. PEGDA curing agent was synthesized in three steps starting from PEG according to our previous report 26. …”
In this research, diglycidyl ethers of bisphenol-A (BADGE) and polyethylene glycol (PEGDGE) were binarily cured with a mixture of diamine curing agents including isophorone diamine and polyethylene glycol diamine (PEGDA) in the absence/presence of aminated graphene oxide nanoplatelets (AGNPs, 0.5 wt.%). Four molar ratios of diglycidyl ethers and curing agents were used stoichiometrically in isothermal curing systems. The films prepared from the epoxy networks were entirely strong and pliable. All epoxy thermosets were evaluated using field emission-scanning electron microscopy (FE-SEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), and diffuse reflectance-ultraviolet/visible spectroscopy (DR-UV/vis). The absorption coefficients of the epoxy and AGNPs-loaded epoxy materials decreased with increasing the molar ratio of PEGDGE resin and polyethylene glycol diamine curing agent. According to dynamic mechanical analysis no phase heterogeneity occurred in the structure of the prepared thermostats. When the thermoset materials were loaded by AGNPs filler, the peaks associated with alpha relaxations shifted to higher temperatures. Moreover, thermogravimetric analysis demonstrated that the thermal stability of the prepared epoxy thermosets slightly increased after the addition of the nanoplatelets. In addition, the thermal resistance of the prepared thermosets decreased to some extent by increasing the participation rate of monomers containing polyoxyethylene.
“…PEGDA curing agent was synthesized in three steps starting from PEG according to our previous report. 26 Figure 1.(A) Synthesis reaction of PEGDGE (B) Chemical structures of BADGE, IPDA and PEGDA.…”
Section: Resultsmentioning
confidence: 99%
“…PEG diamine (PEGDA) was prepared from PEG (Sigma-Aldrich with MW¯ of 600 g/mol) according to our previous work. 26 BADGE was obtained from Sigma-Aldrich with an EEW of 170–176 g/eq (EV = 0.57–0.58 mol/100 g) and used as received. PEGDGE was synthesized from PEG according to the literature.…”
Section: Methodsmentioning
confidence: 99%
“…In our recent studies, Jeffamine D-230 and 3-aminopropyltriethoxysilane were used for amine-functionalization of graphene oxide nanoflakes and silica nanospheres, respectively. 23,24 The functionalized nanofillers were then used in polyoxyalkylene-containing binary epoxy-amine systems. Various kinds of polyoxyalkylene segments such as polyoxybuthylene and polyoxyethylene can cause more flexibility in the epoxy thermoset films.…”
Section: Introductionmentioning
confidence: 99%
“…b) shows the structure of other monomers used. PEGDA curing agent was synthesized in three steps starting from PEG according to our previous report 26. …”
In this research, diglycidyl ethers of bisphenol-A (BADGE) and polyethylene glycol (PEGDGE) were binarily cured with a mixture of diamine curing agents including isophorone diamine and polyethylene glycol diamine (PEGDA) in the absence/presence of aminated graphene oxide nanoplatelets (AGNPs, 0.5 wt.%). Four molar ratios of diglycidyl ethers and curing agents were used stoichiometrically in isothermal curing systems. The films prepared from the epoxy networks were entirely strong and pliable. All epoxy thermosets were evaluated using field emission-scanning electron microscopy (FE-SEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), and diffuse reflectance-ultraviolet/visible spectroscopy (DR-UV/vis). The absorption coefficients of the epoxy and AGNPs-loaded epoxy materials decreased with increasing the molar ratio of PEGDGE resin and polyethylene glycol diamine curing agent. According to dynamic mechanical analysis no phase heterogeneity occurred in the structure of the prepared thermostats. When the thermoset materials were loaded by AGNPs filler, the peaks associated with alpha relaxations shifted to higher temperatures. Moreover, thermogravimetric analysis demonstrated that the thermal stability of the prepared epoxy thermosets slightly increased after the addition of the nanoplatelets. In addition, the thermal resistance of the prepared thermosets decreased to some extent by increasing the participation rate of monomers containing polyoxyethylene.
“…Epoxy (EP) is one of the most commonly used industrial materials. Owing to its excellent properties, such as high adhesive capacity, excellent chemical stability, and good solvent resistance, it is a very widely used thermosetting resin [ 1 , 2 ]. It has been widely reported that the addition of inorganic powders, such as silicon carbide (SiC), SiO 2 , graphite, etc., can significantly improve the mechanical properties, heat resistance and wear resistance of EP [ 3 , 4 , 5 ].…”
In order to improve the tribological properties of epoxy (EP), EP composites were prepared by filling different proportions of silicon carbide (SiC) particles and molybdenum disulfide (MoS2) powder. SiC and MoS2 particle surfaces were modified by the silane coupling agent KH560 to improve dispersion and avoid agglomeration of the inorganic particles in the EP resin matrix. The effect of different proportions of modified MoS2 content on the tribological properties of SiC/EP composites, and the wear mechanism of the worn surface, were investigated when the filler content was fixed at 55 wt.%. The results indicate that the friction and wear properties of modified MoS2/SiC/EP composites are better than SiC/EP composites without modified MoS2. When the modified MoS2 content is 4 wt.%, the average friction coefficient and volume wear rate of the modified MoS2/SiC/EP composite are 0.447 and 14.39 × 10−5 mm3/N·m, respectively, which is reduced by 10.06% and 52.13% in comparison with that of the 55 wt.% SiC/EP composite. Furthermore, the average friction coefficient of a composite containing 4 wt.% MoS2 is 16.14% lower, and the volume wear rate is 92.84% lower than that of pure EP.
In this study, to improve the physico‐mechanical properties of epoxy thermosets, simultaneous curing of two resins with a stoichiometric amount of an aromatic amine hardener was investigated. The two resins used included the well‐known diglycidyl ether of bisphenol A (DGEBPA) with relatively rigid molecular structure and a diglycidyl ether derived from a popular polymer, polyethylene glycol (PEG), with loose molecular structure (DGEPEG). DGEPEG was used in amounts of 10 and 25 mol% in the resin mixture. A single‐resin curing process, including only DGEBA, was also examined. Before isothermal curing, differential scanning calorimetry (DSC) was used to determine the position of the curing exotherm. To ensure the completion of the curing processes, infra‐red (IR) and DSC techniques were performed on both simultaneously‐cured thermosets and the control thermoset. The thermogravimetric analysis (TGA) of the prepared thermosets showed that the addition of DGEPEG resin in the curing process of DGEBA resin has no significant effect on reducing the thermal resistance of the thermoset. In addition, the storage moduli (E′) and the damping coefficients (tan δ) were measured by dynamic mechanical analysis (DMA). As the mole percentage of DGEPEG resin increased, the rapid drop in the E′ value and the α‐relaxation, which is a measure of the glass transition (Tg), occurred at lower temperatures.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
