Effect of graphene oxide on photo- and thermal curing of chalcone–based benzoxazine resins

Salahuddin, Nehal; Rehab, Ahmed; El-Deeb, Ibrahim Yussif; Elmokadem, Reem

doi:10.1007/s00289-021-03590-4

Cited by 5 publications

(4 citation statements)

References 44 publications

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“…This carbon-based substance can lower the curing reaction temperature, reducing the probability of thermal initiator burnout [ 40 ]. As a result, they can minimize activation energy and accelerate the initial polymerization reaction [ 41 ].…”

Section: Introductionmentioning

confidence: 99%

Degree of Cure, Microstructures, and Properties of Carbon/Epoxy Composites Processed via Frontal Polymerization

Shams,

Papon,

Shinde

et al. 2024

Polymers

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The frontal polymerization (FP) of carbon/epoxy (C/Ep) composites is investigated, considering FP as a viable route for the additive manufacturing (AM) of thermoset composites. Neat epoxy (Ep) resin-, short carbon fiber (SCF)-, and continuous carbon fiber (CCF)-reinforced composites are considered in this study. The evolution of the exothermic reaction temperature, polymerization frontal velocity, degree of cure, microstructures, effects of fiber concentration, fracture surface, and thermal and mechanical properties are investigated. The results show that exothermic reaction temperatures range between 110 °C and 153 °C, while the initial excitation temperatures range from 150 °C to 270 °C. It is observed that a higher fiber content increases cure time and decreases average frontal velocity, particularly in low SCF concentrations. This occurs because resin content, which predominantly drives the exothermic reaction, decreases with increased fiber content. The FP velocities of neat Ep resin- and SCF-reinforced composites are seen to be 0.58 and 0.50 mm/s, respectively. The maximum FP velocity (0.64 mm/s) is observed in CCF/Ep composites. The degree of cure (αc) is observed to be in the range of 70% to 85% in FP-processed composites. Such a range of αc is significantly low in comparison to traditional composites processed through a long cure cycle. The glass transition temperature (Tg) of neat epoxy resin is seen to be approximately 154 °C, and it reduces slightly to a lower value (149 °C) for SCF-reinforced composites. The microstructures show significantly high void contents (12%) and large internal cracks. These internal cracks are initiated due to high thermal residual stress developed during curing for non-uniform temperature distribution. The tensile properties of FP-cured samples are seen to be inferior in comparison to autoclave-processed neat epoxy. This occurs mostly due to the presence of large void contents, internal cracks, and a poor degree of cure. Finally, a highly efficient and controlled FP method is desirable to achieve a defect-free microstructure with improved mechanical and thermal properties.

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Section: Introductionmentioning

confidence: 99%

Degree of Cure, Microstructures, and Properties of Carbon/Epoxy Composites Processed via Frontal Polymerization

Shams,

Papon,

Shinde

et al. 2024

Polymers

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“…Extensive research has been devoted to PBZ thermal stability improvement through molecular structure modification, [5][6][7][8] merging with other polymers [9][10][11] and nanocomposites preparation. [12][13][14][15] POSSs, or polyhedral oligomeric silsesquioxane, are silica nanoparticles of the smallest size conceivable and can be employed to generate POSS hybrids with distinctive selfassembled nanostructures. 16 Fabricated POSS/polymer hybrid materials present a wide range of potential applications in the enhancement of composites' thermal stabilities and insulation properties.…”

Section: Introductionmentioning

confidence: 99%

“…Also, they have been used as high‐performance resin matrices in aerospace, automobile and electronic industries. Extensive research has been devoted to PBZ thermal stability improvement through molecular structure modification, 5–8 merging with other polymers 9–11 and nanocomposites preparation 12–15 . POSSs, or polyhedral oligomeric silsesquioxane, are silica nanoparticles of the smallest size conceivable and can be employed to generate POSS hybrids with distinctive self‐assembled nanostructures 16 .…”

Section: Introductionmentioning

confidence: 99%

Thermal stability and decomposition kinetics of polybenzoxazine and oligomeric polyhedral octaphenyl silsesquioxane nanocomposites

Faghihi,

Azar,

Khonakdar

et al. 2024

Polymers for Advanced Techs

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In this study, the impact of octaphenyl polyhedral oligomeric silsesquioxane (POSS) on the thermal stability of polybenzoxazine resin at 1, 3, and 5 wt% POSS loading through dynamic thermogravimetric analysis (TGA) at heating rates of 10, 20, 30 and 40°C min−1 was investigated. Besides, the decomposition kinetics of polybenzoxazine resin (PBZ) and various nanocomposites were studied using Kissinger, Friedman, Flynn‐Wall‐Ozawa (FWO) and Coats‐Redfern (CR) models and also, the activation energies of samples were calculated. At first, benzoxazine monomer was synthesized and then nanocomposites were prepared via solution mixing method. The qualitative dispersion of nanoparticles in benzoxazine resin was examined through the utilization of scanning electron microscopy and x‐ray diffraction experiments. The results showed that the addition of nanoparticles improved the thermal stability of PBZ resin specially at 1 wt% POSS loading and at higher POSS content the thermal stability of the resin decreased. As determined by TGA, the char yield of resin was enhanced by 2.6% upon the addition of 1 wt% nanoparticles. In addition, in 1 weight percent of nanoparticles, as the heating rate rose from 10 to 40°C min−1, the Integral Program Decomposition Temperature (IPDT) has increased by about 260°C, and this increase is about 183°C compared to the resin, and also elevating the heating rate, Td (5%) and Td (10%) weight loss of samples shifted to higher temperatures. The degradation mechanism of the resin and nanocomposites was evaluated through Kissinger, Friedman, FWO and CR models. The results displayed that the addition of 1 wt% nanoparticles increased the activation energy (Ea) values of the nanocomposites compared to that of neat resin and above this filler content, the Ea values decreased. The findings derived from the FWO model indicated that the inclusion of a 1 wt% filler raised the Ea values of the first and second stages of PBZ resin decomposition from 136–200 and 151–214 kJ mol−1 to 148–210 and 180–228 kJ mol−1, respectively.

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“…In the case of bio-derived phenols, the compounds obtained from plants are of interest. For instance, cardanol [25], urushiol [26], guiacol [23], resorcinol [27], chavicol [28], eugenol [29], coumarin [30], rosin [24], vanillin [31,32], lignin [33], and chalcone [34] are reported as substitutes for petroleum-based phenols. The usage of bio-derived feedstock is not only known for solving environmental issues but also for the improvement of various physicochemical properties and thermal stability [35,36].…”

Section: Introductionmentioning

confidence: 99%

Partially Bio-Based Benzoxazine Monomers Derived from Thymol: Photoluminescent Properties, Polymerization Characteristics, Hydrophobic Coating Investigations, and Anticorrosion Studies

Suesuwan,

Suetrong,

Yaemphutchong

et al. 2024

Polymers

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In this work, four thymol-based benzoxazines were synthesized using four primary amines with different chain lengths, namely methylamine, ethylamine, 1-propylamine, and 1-butylamine, which are then named T-m, T-e, T-p, and T-b, respectively. The optical properties of the synthesized thymol-based benzoxazines were examined via the photoluminescent study of their solutions in acetone. The results show that all the prepared benzoxazines emitted blue light with the maximum wavelengths from 425 to 450 nm when irradiated by the excitation wavelengths from 275 to 315 nm. The maximum excitation wavelengths are found to be 275 nm. The polymerization of the thymol-based benzoxazines is triggered by heat treatments with different conditions (160, 180, and 200 °C for 1 h). According to the FTIR results, the heat-curing process introduces a presence of the OH peak, of which intensity increases as the curing temperature increases. Thermal decompositions of thymol-based benzoxazines regarding TGA analyses reveal the enhancement of thermal stability of the benzoxazines with respect to the N-substituent chain length, as significantly observed the change in the first thermal decomposition at temperature ranged from 253 to 260 °C. Synthesized benzoxazine derivatives are further employed to coat the substrate, e.g., the glass slides. The investigation of the water contact angle shows that the coating of the benzoxazines onto the surface improves the hydrophobicity of the substrate, resulting in the enlargement of the contact angle from 25.5° to 93.3°. Moreover, the anticorrosion performance of the polybenzoxazine coatings is examined using potentiodynamic polarization techniques. The results illustrate the anticorrosion efficiency of the thymol-based polybenzoxazine up to 99.99%. Both hydrophobic and electrochemical studies suggest the feasibility for employing benzoxazines in anticorrosion coating applications.

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Effect of graphene oxide on photo- and thermal curing of chalcone–based benzoxazine resins

Cited by 5 publications

References 44 publications

Degree of Cure, Microstructures, and Properties of Carbon/Epoxy Composites Processed via Frontal Polymerization

Degree of Cure, Microstructures, and Properties of Carbon/Epoxy Composites Processed via Frontal Polymerization

Thermal stability and decomposition kinetics of polybenzoxazine and oligomeric polyhedral octaphenyl silsesquioxane nanocomposites

Partially Bio-Based Benzoxazine Monomers Derived from Thymol: Photoluminescent Properties, Polymerization Characteristics, Hydrophobic Coating Investigations, and Anticorrosion Studies

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