Journal articles: 'Epoxy resins Physiological effect'

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Ballal, Nidambur Vasudev, Amal Roy, and Matthias Zehnder. "Effect of Sodium Hypochlorite Concentration in Continuous Chelation on Dislodgement Resistance of an Epoxy Resin and Hydraulic Calcium Silicate Sealer." Polymers 13, no. 20 (October 11, 2021): 3482. http://dx.doi.org/10.3390/polym13203482.

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The conditioning of the root canal wall during chemo-mechanical root canal treatment differentially affects the adhesion of root canal sealers. This investigation evaluated the impact of sodium hypochlorite (NaOCl) concentration as used in a root canal irrigation concept called continuous chelation, with 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP) contained in the NaOCl solution that is applied. Fourier-transform infrared spectra of the dentinal wall were gathered. The consequential effects on push-out bond strength of an epoxy resin (AH Plus) versus a hydraulic CaSi sealer (BioRoot RCS) were assessed. Single-rooted extracted human teeth were used and irrigated with pure NaOCl at a concentration of 0% (physiological saline), 2.5%, or 5.25%. Dual Rinse HEDP (9%) was added to the solutions, or not added for further control. Pure NaOCl solutions caused a decrease in the amide III: phosphate ratios, which was counter-acted by the addition of HEDP. It was observed that the adhesion of the epoxy resin sealer under investigation was negatively affected by this NaOCl deproteinization of the canal wall in a dose-dependent manner, while the opposite was observed with the CaSi sealer. HEDP when used in conjunction with NaOCl was beneficial for the adhesion of both sealers.

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D'Angelo, Stefania, Marika Scafuro, and Rosaria Meccariello. "BPA and Nutraceuticals, Simultaneous Effects on Endocrine Functions." Endocrine, Metabolic & Immune Disorders - Drug Targets 19, no. 5 (June 3, 2019): 594–604. http://dx.doi.org/10.2174/1871530319666190101120119.

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Background: Bisphenol A (BPA) is worldwide diffused as a monomer of epoxy resins and polycarbonate plastics and has recognized activity as Endocrine Disruptor (ED). It is capable to interfere or compete with endogenous hormones in many physiological activities thus having adverse outcomes on health. Diet highly affects health status and in addition to macronutrients, provides a large number of substances with recognized pro-heath activity, and thus called nutraceuticals. Objective: This mini-review aims at summarizing the possible opposite and simultaneous effects of BPA and nutraceuticals on endocrine functions. The possibility that diet may represent the first instrument to preserve health status against BPA damages has been discussed. Methods: The screening of recent literature in the field has been carried out. Results: The therapeutic and anti-oxidant properties of many nutraceuticals may reverse the adverse health effects of BPA. Conclusion: In vitro and in vivo studies provided evidence that nutraceuticals can preserve the health. Thus, the use of nutraceuticals can be considered a support for clinical treatment. In conclusion, dietary remediation may represent a successful therapeutic approach to maintain and preserve health against BPA damage.

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Duan, Chen, and Duan. "Transcriptional Analysis of Chlorella Pyrenoidosa Exposed to Bisphenol A." International Journal of Environmental Research and Public Health 16, no. 8 (April 16, 2019): 1374. http://dx.doi.org/10.3390/ijerph16081374.

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Bisphenol A (BPA) is the raw material of 71% of polycarbonate-based resins and 27% of epoxy-based resins which are used for coating metal-based food and beverage cans. Meanwhile, it is taken into account as a typical environmental pollutant. Hormesis may occur in algae exposed to BPA. In this study, the effects of BPA on Chlorella pyrenoidosa were assessed based on growth inhibition and transcriptome analysis. We have focused on two exposure scenarios as follows: (1) exposure to a low stimulation concentration (0.1 mg.L−1, 19.35% promotion in cell density on the 3rd day); (2) exposure to a high inhibition concentration (10 mg.L−1, 64.71% inhibition in cell density on the 3rd day). Transcriptome analysis showed enrichment in nucleotide transport, single-organism transport, cellular respiration. Among them, adenosine triphosphate (ATP) synthase and Nicotinamide adenine dinucleotide (NADH) dehydrogenase were upregulated under 0.1 mg.L−1 BPA treatment. These changes enhanced the physiological and energy metabolic pathways of C. pyrenoidosa, thereby stimulating cell proliferation. At exposure to the high BPA, severe inhibited changes in the expression levels of several pathways were observed, which were related to tricarboxylic acid (TCA) cycle, glycolysis, fatty acid metabolism, oxidative phosphorylation, and photosynthesis. Therefore, BPA could negatively affect growth inhibition through the multiple energy metabolism processes. These results may result in a deeper insight into BPA-induced biphasic responses in algae, and provide vital information to assess the potential ecological risks of exposure to BPA in an aquatic ecosystem.

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Posnack, Nikki Gillum, Daina Brooks, Akhil Chandra, Rafael Jaimes, Narine Sarvazyan, and Matthew Kay. "Physiological response of cardiac tissue to bisphenol a: alterations in ventricular pressure and contractility." American Journal of Physiology-Heart and Circulatory Physiology 309, no. 2 (July 15, 2015): H267—H275. http://dx.doi.org/10.1152/ajpheart.00272.2015.

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Biomonitoring studies have indicated that humans are routinely exposed to bisphenol A (BPA), a chemical that is commonly used in the production of polycarbonate plastics and epoxy resins. Epidemiological studies have shown that BPA exposure in humans is associated with cardiovascular disease; however, the direct effects of BPA on cardiac physiology are largely unknown. Previously, we have shown that BPA exposure slows atrioventricular electrical conduction, decreases epicardial conduction velocity, and prolongs action potential duration in excised rat hearts. In the present study, we tested if BPA exposure also adversely affects cardiac contractile performance. We examined the impact of BPA exposure level, sex, and pacing rate on cardiac contractile function in excised rat hearts. Hearts were retrogradely perfused at constant pressure and exposed to 10−9-10−4 M BPA. Left ventricular developed pressure and contractility were measured during sinus rhythm and during pacing (5, 6.5, and 9 Hz). Ca2+ transients were imaged from whole hearts and from neonatal rat cardiomyocyte layers. During sinus rhythm in female hearts, BPA exposure decreased left ventricular developed pressure and inotropy in a dose-dependent manner. The reduced contractile performance was exacerbated at higher pacing rates. BPA-induced effects on contractile performance were also observed in male hearts, albeit to a lesser extent. Exposure to BPA altered Ca2+ handling within whole hearts (reduced diastolic and systolic Ca2+ transient potentiation) and neonatal cardiomyocytes (reduced Ca2+ transient amplitude and prolonged Ca2+ transient release time). In conclusion, BPA exposure significantly impaired cardiac performance in a dose-dependent manner, having a major negative impact upon electrical conduction, intracellular Ca2+ handing, and ventricular contractility.

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Riesbeck, Sarah, Hannes Petruschke, Ulrike Rolle-Kampczyk, Christian Schori, Christian H. Ahrens, Christian Eberlein, Hermann J. Heipieper, Martin von Bergen, and Nico Jehmlich. "Adaptation and Resistance: How Bacteroides thetaiotaomicron Copes with the Bisphenol A Substitute Bisphenol F." Microorganisms 10, no. 8 (August 9, 2022): 1610. http://dx.doi.org/10.3390/microorganisms10081610.

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Bisphenols are used in the process of polymerization of polycarbonate plastics and epoxy resins. Bisphenols can easily migrate out of plastic products and enter the gastrointestinal system. By increasing colonic inflammation in mice, disrupting the intestinal bacterial community structure and altering the microbial membrane transport system in zebrafish, bisphenols seem to interfere with the gut microbiome. The highly abundant human commensal bacterium Bacteroides thetaiotaomicron was exposed to bisphenols (Bisphenol A (BPA), Bisphenol F (BPF), Bisphenol S (BPS)), to examine the mode of action, in particular of BPF. All chemicals caused a concentration-dependent growth inhibition and the half-maximal effective concentration (EC50) corresponded to their individual logP values, a measure of their hydrophobicity. B. thetaiotaomicron exposed to BPF decreased membrane fluidity with increasing BPF concentrations. Physiological changes including an increase of acetate concentrations were observed. On the proteome level, a higher abundance of several ATP synthase subunits and multidrug efflux pumps suggested an increased energy demand for adaptive mechanisms after BPF exposure. Defense mechanisms were also implicated by a pathway analysis that identified a higher abundance of members of resistance pathways/strategies to cope with xenobiotics (i.e., antibiotics). Here, we present further insights into the mode of action of bisphenols in a human commensal gut bacterium regarding growth inhibition, and the physiological and functional state of the cell. These results, combined with microbiota-directed effects, could lead to a better understanding of host health disturbances and disease development based on xenobiotic uptake.

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Hoque, Emdadul, Khaled Mahmud Sujan, Md Suman Mia, Md Iqramul Haque, Afrina Mustari, Mohammad Alam Miah, and Md Kamrul Islam. "Effects of bisphenol-A (BPA) on body weight, hematological parameters and histo-texture of kidney in swiss albino mice." Asian Journal of Medical and Biological Research 6, no. 4 (January 7, 2021): 635–40. http://dx.doi.org/10.3329/ajmbr.v6i4.51229.

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Bisphenol-A (BPA) is one of the highest volume chemicals produced world-wide and used in the manufacture of plastics and epoxy resins that are pervasive in our environment and daily lives. The present research was carried out to investigate the effects of two different doses of Bisphenol-A (BPA) on the body weight, hematological parameters and patho-physiological changes of kidney in mice. For this study, fifteen mice, 6 to 8 weeks of age with an average bwt 27.10±0.5 gm, were randomly divided into three groups (n= 5). Group A (control) received only normal mouse pellet while group B and group C received pellet mixed with BPA @ 50 mg and 100 mg / kg bwt daily for 12 weeks, respectively. At the end of the experiment, blood and tissues were collected and processed for hematological and histopathological examination. Results showed that BPA- treated mice caused significant elevation (p<0.01) in weight gain even treated with low dose (50mg) of BPA. The mice exposed to high dose of BPA (100 mg) showed marked reduction (p<0.05) in total erythrocyte count (TEC), significant decreased (p<0.01) in hemoglobin concentration (Hb) and packed cell volume (PCV). Histopathological alterations were detected in the kidneys of BPA-treated mice. In conclusion, this study suggested that BPA exerts deleterious impacts on hematological parameters including association with renal injuries. Asian J. Med. Biol. Res. December 2020, 6(4): 635-640

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Ballal, Nidambur Vasudev, Anja Ivica, Pamela Meneses, Raj Kumar Narkedamalli, Thomas Attin, and Matthias Zehnder. "Influence of 1-Hydroxyethylidene-1,1-Diphosphonic Acid on the Soft Tissue-Dissolving and Gelatinolytic Effect of Ultrasonically Activated Sodium Hypochlorite in Simulated Endodontic Environments." Materials 14, no. 10 (May 13, 2021): 2531. http://dx.doi.org/10.3390/ma14102531.

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The addition of Dual Rinse HEDP, an etidronate powder, to a sodium hypochlorite (NaOCl) solution can create a combined single endodontic irrigant with a soft tissue-dissolving and a decalcifying effect, which can replace traditional alternating irrigation with chemically non-compatible solutions. While the short-term compatibility between NaOCl and 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP) has been shown, it remains unclear whether ultrasonic activation of a combined NaOCl & HEDP solution immediately reduces the available chlorine and/or renders the NaOCl ineffective in dissolving organic tissue remnants. This was tested in three experiments: (1) direct activation in test tubes in an ultrasonic bath and then the activation by an ultrasonically oscillating tip (IrriSafe) in (2) an epoxy resin model containing a simulated isthmus filled with gelatin, and (3) extracted teeth with simulated resorption cavities filled with soft tissue. The control solutions were physiological saline and 2.5% NaOCl without HEDP. In (1), available chlorine after 30 s of ultrasonic activation (37 kHz) of test and control solution was assessed, as well as shrimp tissue weight loss in direct exposure. In (2) and (3), the ultrasonic tip was driven at 1/3 of full power using the respective unit, and areas of removed gelatin from the isthmus and tissue weight loss were used as the outcomes, respectively. Experiment (1) revealed no negative impact by HEDP on available chlorine (1), while all three experiments showed a highly significant (p > 0.001) synergistic effect, which was not hampered by HEDP, between NaOCl and ultrasonic activation regarding tissue weight loss (1, 3) and dissolution of gelatin (2).

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Vyhnánková, Michaela, Jakub Hodul, and Jiří Bydžovský. "Issue of Epoxy-Based Coatings System Crystallization and Effect of Partial Crystallinity on Mechanical Parameters." Key Engineering Materials 776 (August 2018): 147–52. http://dx.doi.org/10.4028/www.scientific.net/kem.776.147.

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Crystallization of bisphenol A-based and bisphenol F-based epoxy resins is the common property of the oligomers. However, producers of paints, coatings and other systems based on these epoxy resins are making efforts to slow down the crystallization process as much as possible. Thereby the shelf life is prolonged, while improving the competitiveness of their products. The main topic is the generalization of factors influencing the crystallization process of bisphenol A-based and bisphenol F-based epoxy resins, the validation of new approaches to possibility of influencing their crystallization process, and the determination of possibility of using a certain degree of crystallinity of bisphenol A-based and bisphenol F-based epoxy resins when preparing and producing paint and coating systems. Two types of the epoxy resins in formulations of paint and coating and other systems, namely: diglycidyl ether of bisphenol A (DGEBA) and diglycidyl ether of bisphenol F (DGEBF) were used. The tendency to crystallize not only for the pure epoxy resins, but also various mixtures with reactive diluents, fillers, etc. was determined according to the standard ISO 4895 Plastics – Liquid epoxy resins – Determination of tendency to crystallize. Furthermore, the crystallinity of individual samples was determined. The effectiveness of potentially active nucleating agents such as precipitated calcium carbonate, DGEBA, and DGEBF crystals, etc. was selected and tested according to the ISO 4895 standard. The effectiveness of potentially active admixtures with crystallization retardation effect was selected and tested according to the ISO 4895 standard. Selected samples of the epoxy resins with a specified degree of crystallinity were cured with 3-aminomethyl-3,5,5-trimethylcyclohexylamine (IPD) based crosslinking agent. Mechanical parameters such as compressive strength and flexural strength were determined. The influence of crystallinity on selected mechanical parameters was also observed.

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Zarybnicka, Lucie, Jana Machotova, Radka Kopecka, Radek Sevcik, Martina Hudakova, Jaroslav Pokorny, and Jiri Sal. "Effect of Cyclotriphosphazene-Based Curing Agents on the Flame Resistance of Epoxy Resins." Polymers 13, no. 1 (December 22, 2020): 8. http://dx.doi.org/10.3390/polym13010008.

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Epoxy resins are characterized by excellent properties such as chemical resistance, shape stability, hardness and heat resistance, but they present low flame resistance. In this work, the synthesized derivatives, namely hexacyclohexylamino-cyclotriphosphazene (HCACTP) and novel diaminotetracyclohexylamino-cyclotriphosphazene (DTCATP), were applied as curing agents for halogen-free flame retarding epoxy materials. The thermal properties and combustion behavior of the cured epoxy resins were investigated. The obtained results revealed that the application of both derivatives significantly increased flame resistance. The epoxy resins cured with HCACTP and DTCATP exhibited lower total heat release together with lower total smoke production compared to the epoxy materials based on conventional curing agents (dipropylenetriamine and ethylenediamine). Comparing both derivatives, the HCACTP-cured epoxy resin was found to provide a higher flame resistance. The designed novel class of epoxy materials may be used for the preparation of materials with improved flame resistance properties in terms of flame spreading and smoke inhibition.

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Monnerie, L., J. L. Halary, and F. Lauprêtre. "Effect of local dynamics on model epoxy resins." Macromolecular Symposia 98, no. 1 (July 1995): 983. http://dx.doi.org/10.1002/masy.19950980188.

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NUMATA, Shunichi, Nobuo SHIBATA, Masatugu OGATA, Hiroshi HOZOJI, Hiroshi SUZUKI, and Noriyuki KINJO. "Studies on ductilization of epoxy resins. II. Effect of flexibilizer on mechanical destruction properties of epoxy resins." KOBUNSHI RONBUNSHU 45, no. 6 (1988): 473–80. http://dx.doi.org/10.1295/koron.45.473.

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OGATA, Masatsugu, Noriyuki KINJO, Shuji EGUCHI, Tatuo KAWATA, and Takasi URANO. "Effect of the molecular weights of raw epoxy resins on the physical properties of cured epoxy resins." KOBUNSHI RONBUNSHU 47, no. 8 (1990): 639–47. http://dx.doi.org/10.1295/koron.47.639.

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Yu, Seoyoon, Wonjoo Lee, Bongkuk Seo, and Chung-Sun Lim. "Synthesis of Benzene Tetracarboxamide Polyamine and Its Effect on Epoxy Resin Properties." Polymers 10, no. 7 (July 16, 2018): 782. http://dx.doi.org/10.3390/polym10070782.

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Epoxy resins have found various industrial applications in high-performance thermosetting resins, high-performance composites, electronic-packaging materials, adhesives, protective coatings, etc., due to their outstanding performance, including high toughness, high-temperature performance, chemical and environmental resistance, versatile processability and adhesive properties. However, cured epoxy resins are very brittle, which limits their applications. In this work, we attempted to enhance the toughness of cured epoxy resins by introducing benzene tetracarboxamide polyamine (BTCP), synthesized from pyromellitic dianhydride (PMDA) and diamines in N-methyl-2-pyrrolidone (NMP) solvent. During this reaction, increased viscosity and formation of amic acid could be confirmed. The chemical reactions were monitored and evidenced using 1H-NMR spectroscopy, FT-IR spectroscopy, water gel-phase chromatography (GPC) analysis, amine value determination and acid value determination. We also studied the effect of additives on thermomechanical properties using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamical mechanical analysis (DMA), thermomechanical analysis (TMA) and by measuring mechanical properties. The BTCP-containing epoxy resin exhibited high mechanical strength and adhesion strength proportional to the amount of BTCP. Furthermore, field-emission scanning electron microscopy images were obtained for examining the cross-sectional morphology changes of the epoxy resin specimens with varying amounts of BTCP.

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Yu, Ming Ming, Lin Fang, Min Yang, Hong Li, Mu Su Ren, and Jin Liang Sun. "Effect of DFA Modification on Thermal Properties of Multifunctional Epoxy/Anhydride Systems." Key Engineering Materials 748 (August 2017): 35–38. http://dx.doi.org/10.4028/www.scientific.net/kem.748.35.

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The thermal stabilities of two amine based multifunctional epoxy resins (TGDDE/MNA & TGBAPP/MNA) and two dimer carboxylic acid (DFA) toughened resins (DFA-TGDDE/MNA & DFA-TGBAPP/MNA) were comparatively investigated with the thermo-gravimetric analysis (TG). The TG parameters of the resins indicated that the thermal stability of the resins was increased after the modification. Furthermore, the thermal degradation kinetics was studied with a dynamic method according to Ozawa model, which explained this phenomenon.

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Vaseneva, Irina N., Petr A. Sitnikov, Anna G. Belykh, Irina Yu Chukicheva, Evgeniy V. Buravlev, and Aleksandr V. Kutchin. "USE AMINOMETHYLTERPENOPHENOLS IN EPOXY RESINS." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 61, no. 7 (June 18, 2018): 114. http://dx.doi.org/10.6060/ivkkt.20186107.5580.

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Aminomethylterpenophenols differing in the position of the amino group and its alkyl substituents have been studied as catalysts in the preparation of epoxy resins and stabilizers for their thermal degradation to produce materials with high physicomechanical and thermo-oxidative characteristics. The heat effects of anionic polymerization of an epoxy oligomer in the presence of 2,4,6-tris (dimethylaminomethyl) phenol (UP-606/2), 2-dibutylaminomethyl-6-isobornyl-4-methylphenol (I), 2-isobornyl-4-dimethylaminomethyl-6-methylphenol (II), 2-dimethylaminomethyl-6-isobornyl-4-methylphenol (III), 2,6-diisobornyl-4-dimethylaminomethylphenol (IV) were studied using DSC method. The DSC curves exhibit exothermic peaks, which relate to the polymerization of the oligomer. It is shown that terpenophenols with a dimethylaminomethyl group in the para position relative to the OH group have the highest activity. Heat effects were studied in the polycondensation of an epoxy oligomer with iso-MTHPA in the presence of aminomethylterpenophenols as catalysts. It has been shown that compounds II and IV reduce the temperature of the onset of the reaction by 62 and 8 °C, respectively, compared with the commercially available UP-606/2, and in addition the exothermic effect (Q) is increased by 10 J/g and the energy activation (Ea) by 21 kJ/mol of polycondensation reaction with compound II. Aminomethylterpenephenols improve the resistance of the epoxy resin to thermal aging, in which a reduction in strength from 9 to 23% is observed, in the case of UP-606/2, the strength is reduced by 30%. It has been established that the activation energies of the thermooxidative degradation of resins obtained by introducing compounds II and IV are higher by 10 and 40%, respectively, than when using UP-606/2. Strength characteristics of a polymer matrix containing para-dimethylaminomethyl terpenophenol are higher by 25% than with the use of an industrial analogue - UP-606/2 (2,4,6-tris (dimethylaminomethyl) phenol). It was found that the resins obtained with the use of the catalysts 2-isobornyl-4-dimethylaminomethyl-6-methylphenol and 2,6-diisobornyl-4-dimethylaminomethylphenol have the greatest resistance to thermal oxidation.For citation:Vaseneva I.N., Sitnikov P.A., Belykh A.G., Chukicheva I.Yu., Buravlev E.V., Kutchin A.V. Use aminomethylterpenophenols in epoxy resins. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 7. P. 113-120

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Zhao, Yixin, Rui Xu, Yao Xiao, Hailou Wang, Wei Zhang, and Guangyu Zhang. "Mechanical Performances of Phenolic Modified Epoxy Resins at Room and High Temperatures." Coatings 12, no. 5 (May 8, 2022): 643. http://dx.doi.org/10.3390/coatings12050643.

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Epoxy is an important resin matrix and has been widely applied in laminated composites as a coating or adhesive material. In this article, the phenolic was applied to modify the mechanical properties of epoxy resin. The phenolic modified epoxy resins with various phenolic content were prepared via a polytetrafluoroethylene mould, and the phenolic modified epoxy-based plain woven laminated composites (PWLCs) were manufactured via vacuum assisted resin transfer method for further study of phenolic modified epoxy resins’ mechanical properties. The compression tests were performed perpendicularly to thickness at 2 mm/min to investigate the mechanical performances of phenolic modified epoxy resins and epoxy-based PWLCs. The results showed that the addition of phenolic into epoxy could improve the mechanical performances of epoxy resins and epoxy-based composites at room temperature, and the phenolic influenced epoxy-based PWLC more than epoxy matrix at room temperature. However, at high temperatures, the addition of phenolic decreased the mechanical performances of epoxy resins and epoxy-based composites, and the adverse effect of phenolic became more serious with the increase of phenolic content at high temperature. In addition, the thermogravimetric analyses were also conducted from 30 °C to 800 °C on phenolic modified epoxy resins and the results showed that the phenolic modified epoxy resin had an earlier loss in weight than unmodified epoxy resin. The earlier loss in weight meant that the addition of phenolic into epoxy resin led to the formation of unstable molecules at high temperature.

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Das, Abhishek, and Gautam Sarkhel. "Effect of stoichiometric ratios for synthesized epoxy phenolic novolac (EPN) resins on their physicochemical, thermomechanical and morphological properties." Pigment & Resin Technology 45, no. 4 (July 4, 2016): 265–79. http://dx.doi.org/10.1108/prt-08-2014-0060.

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Purpose The purpose of this paper is to study the effect of various stoichiometric ratios for synthesised epoxy phenolic novolac (EPN) resins on their physicochemical, thermomechanical and morphological properties. Design/methodology/approach In the present study, EPN (EPN-1, EPN-2, EPN-3, EPN-4 and EPN-5) resins were synthesised by varying five types of different stoichiometric ratios for phenol/formaldehyde along with the corresponding molar ratios for novolac/epichlorohydrin. Their different physicochemical properties of interest, thermomechanical properties as well as morphological properties were studied by means of cured samples with the variation of its stoichiometric ratios. Findings The average functionality and reactivity of EPN resin can be controlled by controlling epoxy equivalence as well as cross-linking density upon its curing as all of these factors are internally correlated with each other. Research limitations/implications Epoxy resins are characterised by a three-membered ring known as the epoxy or oxirane group. The capability of the epoxy ring to react with a variety of substrates imparts versatility to the resin. However, these resins have a major drawback of low toughness, and they are also very brittle, which limits their application in products that require high impact and fracture strength. Practical implications Epoxy resins have been widely used as high-performance adhesives and matrix resins for composites because of their outstanding mechanical and thermal properties. Because of their highly cross-linked structure, the epoxy resin disables segmental movement, making them hard, and it is also notch sensitive, having very low fracture energy. Social implications Epoxy resin is widely used in industry as protective coatings and for structural applications, such as laminates and composites, tooling, moulding, casting, bonding and adhesives. Originality/value Systematic study has been done for the first time, as no exact quantitative stoichiometric data for the synthesis of EPN resin were available on the changes of its different properties. Thus, an optimised stoichiometric composition for the synthesis of the EPN resin was found.

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Jain, Preeti, V. Choudhary, and I. K. Varma. "Effect of structure on thermal behaviour of epoxy resins." European Polymer Journal 39, no. 1 (January 2003): 181–87. http://dx.doi.org/10.1016/s0014-3057(02)00191-x.

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El-Sa'ad, Leila, M. I. Darby, and B. Yates. "Moisture absorption by epoxy resins: The reverse thermal effect." Journal of Materials Science 25, no. 8 (August 1990): 3577–82. http://dx.doi.org/10.1007/bf00575392.

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Panthakkal Abdul Muthalif, Mohammed, and Youngson Choe. "Influence of Maleinized Polybutadiene on Adhesive Strength and Toughness of Epoxy Resins." International Journal of Polymer Science 2022 (December 28, 2022): 1–8. http://dx.doi.org/10.1155/2022/9517467.

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This study explored the effect of maleinized polybutadiene (MPB) on the mechanical properties of epoxy resins. Diglycidyl ether of bisphenol-A, an epoxy resin, was modified by incorporating MPB having different molecular weights in order to improve the fracture toughness and peel strength. MPB was mixed with epoxy resin at several concentrations (5, 10, and 15 phr), with the epoxy resin as the major phase and MPB as the minor phase. A comparative study was performed to investigate the influence of MPB on epoxy resins based on their molecular weight difference. Lap shear test results showed that the shear strength of the MPB-modified epoxy resins was superior to that of the neat epoxy resin. At 10 wt% MPB loading, the modified epoxy resin exhibited an 87% enhancement in T-peel strength relative to that of the neat epoxy resin. Moreover, the fracture energy of the modified epoxy system increased proportionally with the amount of MPB in the epoxy matrix. These results indicate that MPB incorporation is a simple and effective method for designing multifunctional epoxy resins, thus facilitating their industrial application in various spheres.

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Zhang, Daijun, Gang Liu, Hui Zhang, Jianwen Bao, Zhong Zhang, Xiaosu Yi, and Xiangbao Chen. "Rheological Properties of Al2O3 Nanoparticle Toughened Epoxy Resins." Advanced Composites Letters 22, no. 5 (September 2013): 096369351302200. http://dx.doi.org/10.1177/096369351302200502.

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The effect of nanoparticle content on the rheological properties of toughened epoxy resins was studied by measuring the isothermal viscosity-time curves of Al2O3 nanoparticle toughened epoxy resin at different temperatures. The chemorheological properties of toughened epoxy resin systems were analysed using the Dual-Arrhenius equation and a corresponding chemorheological model was established. The model agrees well with the experimental results and provides a theoretical basis for rational development of parameters for Al2O3 nanoparticle toughened epoxy resin based composite molding processes.

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Vyhnánková, Michaela, Jakub Hodul, and Jiří Bydžovský. "Epoxy Resin Coatings Crystallization and Influence of Crystallinity on Shore Hardness and Tensile Properties." Solid State Phenomena 276 (June 2018): 173–78. http://dx.doi.org/10.4028/www.scientific.net/ssp.276.173.

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The epoxy resins are very popular and plentifully used synthetic resins. The bisphenol A-based (DGEBA) and bisphenol F-based epoxy resins (DGEBF) crystallization is phenomenon which is for that kind of resins natural. They are undercooled liquids and they tend to form the crystal structure at the ambient temperature. The subject of the research is to determine the effect of some crystallinity of DGEBF on chosen mechanical parameters. The degree of crystallinity was counted through the specific weights of crystallized bisphenol F-based epoxy resins. The prepared crystallized samples of DGEBA/DGEBF mixtures were mixed in appropriate weight ratio with isophorondiamine (IPD) based curing agent. Measured was hardness Shore D according to EN ISO 868 standard and tensile parameters according to EN ISO 527-1 standard. Furthermore, the effect of crystallinity on chosen mechanical parameters was observed. It was found out that with the higher crystallinity maximum tensile stress and hardness increased close to the standard parameters amorphous DGEBA and DGEBF.

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Wu, Xiaochun, Yingguang Li, Nanya Li, Jing Zhou, and Xiaozhong Hao. "Analysis of the effect and mechanism of microwave curing on the chemical shrinkage of epoxy resins." High Performance Polymers 29, no. 10 (October 6, 2016): 1165–74. http://dx.doi.org/10.1177/0954008316671794.

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The microwave cure–induced chemical shrinkage of epoxy resins in composite materials was researched in this article. Four kinds of epoxy resins were cured using the microwave and thermal heating process. An improved device containing fiber Bragg grating sensors was applied to accurately measure the chemical shrinkage–induced linear strains in those samples. Experimental results indicated that the chemical shrinkage of diglycidyl ether of bisphenol A (DGEBA)/polyetheramine (PEA) and tetraglycidyl diaminodiphenylmethane/4,4′-diaminodiphenyl sulfone epoxy resins was significantly reduced by microwave curing, and the reductions about 37.1 and 38.4% were achieved compared with the thermal-cured counterparts. However, the chemical shrinkage of the thermal- and microwave-cured samples was almost the same for DGEBA/methyl tetrahydrophthalic anhydride and DGEBA/dicyandiamide epoxies. In order to analyze the influencing mechanism of microwaves on the chemical shrinkage, the chemical structure of various samples was characterized by using Fourier-transform infrared spectroscopy, and the free volume was measured by positron annihilation lifetime spectrometer. It was found that microwaves can greatly decrease the contents of hydroxyl groups in epoxy resins, leading to the reduction of the chemical shrinkage. Furthermore, the mechanical properties of both microwave- and thermal-cured DGEBA/PEA epoxies were studied, and the results showed that the microwave-cured specimens have a higher impact strength but a lower tensile strength.

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Journal, Baghdad Science. "The synergistic effect of borax and chlorinated paraffin as flame – retardants for epoxy and unsaturated polyester resins." Baghdad Science Journal 5, no. 1 (March 2, 2008): 131–36. http://dx.doi.org/10.21123/bsj.5.1.131-136.

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In this investigation , borax (B) (additive I) and chlorinated paraffin (CP.) (additive II) ,were used as flame retardants for each of epoxy and unsaturated polyester resins in the weight ratios of 2,4,6, & 8% by preparing films of (130×130×3) mm dimensions. Also films of these resins with a mixture of [50%(B.)+50%(CP.)] (additive III) in the same weight ratios were prepared in order to study the synergistic effect of these additives on the flammability of the two resins . Three standard test methods were used to measure the flame retardation which are : 1-ASTM : D-2863 2-ASTM : D-635 3-ASTM : D-3014 The results obtained from these tests indicated that the additives (B),(CP.) and their mixture , gave a good effect as flame retardants for each epoxy and unsaturated polyester resins , but their synergistic effect was more effective than each of them alone. Finally , the compatibility between the additives and resins (which showed a clear effect on retardation) was also studied .

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Varma, Indra K., and P. V. Satya Bhama. "Epoxy Resins: Effect of Amines on Curing Characteristics and Properties." Journal of Composite Materials 20, no. 5 (September 1986): 410–22. http://dx.doi.org/10.1177/002199838602000501.

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Padma, A., R. M. V. G. K. Rao, and G. Nagendrappa. "Effect of prereaction on curing of elastomer-modified epoxy resins." Journal of Applied Polymer Science 65, no. 9 (August 29, 1997): 1751–57. http://dx.doi.org/10.1002/(sici)1097-4628(19970829)65:9<1751::aid-app12>3.0.co;2-q.

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Lorenzo, Luis, and H. Thomas Hahn. "Effect of ductility on the fatigue behavior of epoxy resins." Polymer Engineering and Science 26, no. 4 (February 1986): 274–84. http://dx.doi.org/10.1002/pen.760260403.

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Eliaz, Noam, Eliora Ron, Michael Gozin, Sara Younger, Dvora Biran, and Noam Tal. "Microbial Degradation of Epoxy." Materials 11, no. 11 (October 29, 2018): 2123. http://dx.doi.org/10.3390/ma11112123.

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Epoxy resins have a wide range of applications, including in corrosion protection of metals, electronics, structural adhesives, and composites. The consumption of epoxy resins is predicted to keep growing in the coming years. Unfortunately, thermoset resins cannot be recycled, and are typically not biodegradable. Hence, they pose environmental pollution risk. Here, we report degradation of epoxy resin by two bacteria that are capable of using epoxy resin as a sole carbon source. These bacteria were isolated from soil samples collected from areas around an epoxy and polyurethanes manufacturing plant. Using an array of molecular, biochemical, analytical, and microscopic techniques, they were identified as Rhodococcus rhodochrous and Ochrobactrum anthropi. As epoxy was the only carbon source available for these bacteria, their measured growth rate reflected their ability to degrade epoxy resin. Bacterial growth took place only when the two bacteria were grown together, indicating a synergistic effect. The surface morphology of the epoxy droplets changed significantly due to the biodegradation process. The metabolic pathway of epoxy by these two microbes was investigated by liquid chromatography mass spectrometry. Bisphenol A, 3,3′-((propane-2,2-diylbis(4,1-phenylene))bis(oxy))bis(propane-1,2-diol) and some other constituents were identified as being consumed by the bacteria.

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Ai Du, Bin Zhou, Yunong Li, Xiuyan Li, Junjian Ye, Longxiang Li, Zhihua Zhang, Guohua Gao, and Jun Shen. "Aerogel: a potential three-dimensional nanoporous filler for resins." Journal of Reinforced Plastics and Composites 30, no. 11 (June 2011): 912–21. http://dx.doi.org/10.1177/0731684411407948.

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Considering its special microstructure and unique properties, silica aerogel was chosen as three-dimensional (3D) nanoporous filler for epoxy resin in this paper. Pure epoxy resin (0 wt%), 0.1 wt%, 1 wt%, 5 wt%, 10 wt%, and 100 wt% (pure silica aerogel) aerogel/epoxy composites were fabricated and then characterized by dynamic mechanical analyzer (DMA) and field emission scanning electron microscope. The results showed that small amount of filler efficiently increased the stiffness of the composites, but the stiffness decreased with the increase of the mass fraction of the aerogel in the composites (composites ratio); the glass transition temperature of the composites substantially increased, compared to pure epoxy resin. Also, the compressive modulus of the composites at glassy state, rubbery state, and hardening state were studied, respectively. At last, the effects which presumably affect the properties of aerogel/epoxy composites were discussed. Anchoring effect and interfacial effect were suggested to explain the thermal—mechanical behaviors of the composites with different composite ratio.

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Kwon, Woong, Minwoo Han, Jongwon Kim, and Euigyung Jeong. "Comparative Study on Toughening Effect of PTS and PTK in Various Epoxy Resins." Polymers 13, no. 4 (February 9, 2021): 518. http://dx.doi.org/10.3390/polym13040518.

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This study investigated the toughening effect of in situ polytriazoleketone (PTK) and polytriazolesulfone (PTS) toughening agent when applied to various epoxy resins, such as diglycidyl ether of bisphenol A (DGEBA), diglycidyl ether of bisphenol F (DGEBF), and triglycidyl p-aminophenol (TGAP) with 3,3′-diaminodiphenylsulfone as a curing agent. The fracture toughness, tensile properties, and thermal properties of the prepared epoxy samples were evaluated and compared. When PTK was mixed with DGEBF, the fracture toughness was improved by 27% with 8.6% increased tensile strength compared to the untoughened DGEBF. When PTS was mixed with TGAP, the fracture toughness was improved by 51% without decreasing tensile properties compared to the untoughened TGAP. However, when PTK or PTS was mixed with other epoxy resins, the fracture toughness decreased or improved with decreasing tensile properties. This is attributed to the poor miscibility between the solid-state monomer of PTK (4,4′-bis(propynyloxy)benzophenone (PBP)) or PTS (4,4′-sulfonylbis(propynyloxy)benzene (SPB)) and the epoxy resin, resulting in the polymerization of low molecular weight PTK or PTS in epoxy resin. Therefore, the toughening effect of PTK or PTS can be maximized by the appropriate selection of epoxy resin based on the miscibility between PBP or SPB and the resin.

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Liang, Bing, Tie Zhu Bao, Jun Cao, and Xiao Dong Hong. "Preparation and Properties of Halogen-Free Flame Retardant Epoxy Resins with Aryl Phosphinate Dianhydride Hardener." Advanced Materials Research 328-330 (September 2011): 1335–38. http://dx.doi.org/10.4028/www.scientific.net/amr.328-330.1335.

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Two halogen-free flame retardant epoxy resins were prepared by diglycidyl ether of bisphenol A (DGEBA) epoxy with two compound hardeners. The aryl phosphinate dianhydride BPAODOPE was used as a hardener and flame retardant when coupled with two curing agents, such as methylhexahydrophthalic anhydride (MeHHPA) and maleic anhydride (MA). The effect of the BPAODOPE contents on the fire resistance, thermal properties and mechanical properties of halogen-free flame-retardant epoxy resins were investigated in detail. The results showed that the phosphorus-containing epoxy resin composites had a higher UL-94 grade and char yield, furthermore, the flame retardation and the char yield of the cured epoxy resins increased with an increase of the phosphorus content, the phosphorus content of 1.75% was enough to achieve UL-94 V-1 grade and the best combination properties for the two composites with different hardeners.

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Wu, Liang Ke, and Ji Ying. "Effect of CNT Arrays on Electrical and Thermal Conductivity of Epoxy Resins." Advanced Materials Research 1043 (October 2014): 27–30. http://dx.doi.org/10.4028/www.scientific.net/amr.1043.27.

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With the development of electronic technology, thermal interface materials (TIMs) of excellent thermal conductivity have been desired for circuit integration. In this study, carbon nanotube arrays (CNTAs) were utilized to prepare high thermal conductive composites by infiltration into epoxy resin. The composite was cured in a drying oven at 60 °C for 4 h. The thermal conductivity of the composite along axial direction reaches 2.24 W/mK at 120 oC, which is about 10 times of that of pure epoxy resin. The results indicated that the great promise of epoxy/CNTA composites as thermal interface materials. However, the electrical conductivity still remains at a low level, although it is increased by orders of magnitudes, the insulativity is beneficial for the application of this composite in electrical industry.

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KAMON, Takashi. "Studies on curing of epoxy resins. XV. Effect of accelerators on epoxy-amine curing reaction." KOBUNSHI RONBUNSHU 42, no. 9 (1985): 577–83. http://dx.doi.org/10.1295/koron.42.577.

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Wang, Fuzhong, and Lawrence Drzal. "Development of Stiff, Tough and Conductive Composites by the Addition of Graphene Nanoplatelets to Polyethersulfone/Epoxy Composites." Materials 11, no. 11 (October 30, 2018): 2137. http://dx.doi.org/10.3390/ma11112137.

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In this study, polyethersulfone (PES) was blended into epoxy resins to improve the fracture toughness of the epoxy resin without loss of mechanical properties, and then two grades of pristine graphene nanoplatelets (GnPs) were separately introduced into the PES/epoxy system to fabricate thermally conductive GnPs/PES/epoxy composites with high toughness as well as high stiffness. It was observed that the addition of GnPs obviously affected the final phase morphology by suppressing the phase separation process of the PES modified epoxy due to the increased viscosity and cure-reaction rate of PES/epoxy. The GnPs with a larger lateral dimension revealed a greater reinforcing effect, and the inclusion of 3 wt % GnPs (~5 μm in diameter) endowed the PES/epoxy matrix with a good thermal conductivity and improved the tensile, flexural, and storage modulus by 27.1%, 17.5%, and 15.6% (at 30 °С), respectively. Meanwhile, the fracture toughness was further enhanced by about 29.5% relative to the PES modified epoxy at the same GnPs concentration. The positive results suggest that the modification of epoxy resins using the PES and GnPs is an attractive approach for fabricating tougher and stiffer epoxy-based nanocomposites with multifunctional properties, which could widen the industrial applications of the epoxy resins.

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Zhang, Lichen, Deqi Yi, and Jianwei Hao. "Poly(diallyldimethylammonium) and polyphosphate polyelectrolyte complex as flame retardant for char-forming epoxy resins." Journal of Fire Sciences 38, no. 4 (March 20, 2020): 333–47. http://dx.doi.org/10.1177/0734904120911722.

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The flame retardant poly(diallyldimethylammonium) and polyphosphate polyelectrolyte complex and the curing agent m-Phenylenediamine were blended into diglycidyl ether of bisphenol A (DGEBA)-type epoxy resin to prepare flame-retardant epoxy resin thermosets. The effects of poly(diallyldimethylammonium) and polyphosphate on fire retardancy and thermal degradation behavior of epoxy resins (EP)/poly(diallyldimethylammonium) and polyphosphate composites were tested by Limiting Oxygen Index, UL-94, cone calorimeter tests, and thermogravimetric analysis and compared with pure EP. The results showed that the Limiting Oxygen Index value of EP/poly(diallyldimethylammonium) and polyphosphate composite could reach 31.9%, and UL-94 V-0 rating at 10 wt% poly(diallyldimethylammonium) and polyphosphate loading. Meanwhile the cone calorimetry peak heat release rate and total heat release were reduced up to 55.2% and 21.8%, respectively; smoke production rate and total smoke production were also declined significantly, compared with those of pure epoxy resins. Poly(diallyldimethylammonium) and polyphosphate played a very good flame-retardant effect on epoxy resins.

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Journal, Baghdad Science. "The use of Some Aliphatic Halorgano antimony Compounds as combustion Retarding agents of Unsaturated Polyester and Epoxy Resins." Baghdad Science Journal 7, no. 4 (December 5, 2010): 1389–94. http://dx.doi.org/10.21123/bsj.7.4.1389-1394.

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Four antimony compounds were used in this inves as additives to retard combustion of unsaturated polyester and epoxy resins, namely: 1. Tetraethyl ammonium tribromoethylantimonates (additive I). 2. Tetraethyl ammonium chlorodibromoethylantimonates (additive II). 3. Tetraethyl ammonium trichloroethylantimonates (additive III). 4. Tetraethyl ammonium bromodichloroethylantimonates (additive IV). The effects of these additives on flammability of unsaturated polyester and epoxy resins have been studied by using sheets of the resins with weight percentages of (0.5,1.0,1.5,2.0,2.5&3.0%) of the additives in dimensions of (150 X150X3)mm .Three standard test methods were used to measure the flame retardation which are: (ASTM:D -2863), (ASTM:D-635)and (ASTM:D-3014). The results obtained from these tests indicated that, additive I has a high efficiency as flame retardant causing , self – extinguishing (S.E.) at the percentage of (2.0%) for unsaturated polyester resin and the percentage (2.5%) for epoxy resin. Self – extinguishing (S.E.) of additives II and IV were at the percentage of (2.5%) for unsaturated polyester resin and (3.0%) in the case of epoxy resin. Additive III showed low effect on flammability in both resins

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Martins, Marta, and Celeste M. C. Pereira. "A Study on the Effect of Nano-Magnesium Hydroxide on the Flammability of Epoxy Resins." Solid State Phenomena 151 (April 2009): 72–78. http://dx.doi.org/10.4028/www.scientific.net/ssp.151.72.

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In this work the effect of nano-magnesium hydroxide (nano-Mg(OH)2) on the flammability of epoxy composites is presented and compared with the traditional flame retardant used in just small amounts for epoxy resins, ammonium polyphosphate (APP). The fire reaction properties of epoxy composites were obtained by cone calorimeter tests. It was observed that the flammability of the unfilled resin is significantly changed with nano-Mg(OH)2 addition and reductions of 33, 22 and 23% in the epoxy composite heat release rate peak (PHRR) by incorporating 10%, 5 % and 1% of nano-Mg(OH)2, respectively, were achieved. Cone calorimeter analyses confirm the better behavior of APP composites compared with nano-Mg(OH)2 composites. SEM micrographs show some agglomerations on the distribution of nano-Mg(OH)2 in the epoxy matrix.

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38

Shundo, Atsuomi, Mika Aoki, Satoru Yamamoto, and Keiji Tanaka. "Cross-Linking Effect on Segmental Dynamics of Well-Defined Epoxy Resins." Macromolecules 54, no. 13 (June 15, 2021): 5950–56. http://dx.doi.org/10.1021/acs.macromol.1c00513.

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39

AOKI, Mika. "Effect of Curing Process on Glass Transition Temperature of Epoxy Resins." Nihon Reoroji Gakkaishi 50, no. 1 (February 15, 2022): 83–86. http://dx.doi.org/10.1678/rheology.50.83.

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40

SZCZEPANIAK, BARBARA, PIOTR PENCZEK, and JERZY REJDYCH. "The effect of heating of solid epoxy resins on their properties." Polimery 43, no. 11/12 (November 1998): 732–37. http://dx.doi.org/10.14314/polimery.1998.732.

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41

Blanken, R., J. P. Nater, and E. Veenhoff. "Protective effect of barrier creams and spray coatings against epoxy resins." Contact Dermatitis 16, no. 2 (February 1987): 79–83. http://dx.doi.org/10.1111/j.1600-0536.1987.tb01383.x.

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42

Dumschat, C., H. Müller, H. Rautschek, H. J. Timpe, W. Hoffmann, M. T. Pham, and J. Hüller. "Encapsulation of chemically sensitive field-effect transistors with photocurable epoxy resins." Sensors and Actuators B: Chemical 2, no. 4 (October 1990): 271–76. http://dx.doi.org/10.1016/0925-4005(90)80153-q.

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43

Mohan, Pragyan. "Effect of cobalt on the electrical conductive property of epoxy resins." Journal of Applied Polymer Science 114, no. 4 (November 15, 2009): 1971–75. http://dx.doi.org/10.1002/app.30079.

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44

Kregl, Laura, Gernot M. Wallner, Reinhold W. Lang, and Gerhard Mayrhofer. "Effect of resin modifiers on the structural properties of epoxy resins." Journal of Applied Polymer Science 134, no. 44 (August 4, 2017): 45348. http://dx.doi.org/10.1002/app.45348.

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45

Chi, Hong, Guocheng Zhang, Ning Wang, Yaoguang Wang, Tianduo Li, FuKe Wang, and Chen Ye. "Enhancing the mechanical strength and toughness of epoxy resins with linear POSS nano-modifiers." Nanoscale Advances 4, no. 4 (2022): 1151–57. http://dx.doi.org/10.1039/d1na00757b.

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46

Farcas, Catalina, Oscar Galao, Luigi Vertuccio, Liberata Guadagno, M. Dolores Romero-Sánchez, Iluminada Rodríguez-Pastor, and Pedro Garcés. "Ice-Prevention and De-Icing Capacity of Epoxy Resin Filled with Hybrid Carbon-Nanostructured Forms: Self-Heating by Joule Effect." Nanomaterials 11, no. 9 (September 17, 2021): 2427. http://dx.doi.org/10.3390/nano11092427.

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In this study, CNTs and graphite have been incorporated to provide electrical conductivity and self-heating capacity by Joule effect to an epoxy matrix. Additionally, both types of fillers, with different morphology, surface area and aspect ratio, were simultaneously incorporated (hybrid CNTs and graphite addition) into the same epoxy matrix to evaluate the effect of the self-heating capacity of carbon materials-based resins on de-icing and ice-prevention capacity. The self-heating capacity by Joule effect and the thermal conductivity of the differently filled epoxy resin were evaluated for heating applications at room temperature and at low temperatures for de-icing and ice-prevention applications. The results show that the higher aspect ratio of the CNTs determined the higher electrical conductivity of the epoxy resin compared to that of the epoxy resin filled with graphite, but the 2D morphology of graphite produced the higher thermal conductivity of the filled epoxy resin. The presence of graphite enhanced the thermal stability of the filled epoxy resin, helping avoid its deformation produced by the softening of the epoxy resin (the higher the thermal conductivity, the higher the heat dissipation), but did not contribute to the self-heating by Joule effect. On the other hand, the feasibility of electrically conductive epoxy resins for de-icing and ice-prevention applications by Joule effect was demonstrated.

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Matykiewicz, Danuta, and Katarzyna Skórczewska. "Characteristics and Application of Eugenol in the Production of Epoxy and Thermosetting Resin Composites: A Review." Materials 15, no. 14 (July 11, 2022): 4824. http://dx.doi.org/10.3390/ma15144824.

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The review article presents an analysis of the properties of epoxy and thermosetting resin composites containing eugenol derivatives. Moreover, eugenol properties were characterized using thermogravimeters (TGA) and Fourier-transform infrared spectroscopy (FTIR). The aim of this work was to determine the possibility of using eugenol derivatives in polymer composites based on thermoset resins, which can be used as eco-friendly high-performance materials. Eugenol has been successfully used in the production of epoxy composites as a component of coupling agents, epoxy monomers, flame retardants, curing agents, and modifiers. In addition, it reduced the negative impact of thermoset composites on the environment and, in some cases, enabled their biodegradation. Eugenol-based silane coupling agent improved the properties of natural filler epoxy composites. Moreover, eugenol flame retardant had a positive effect on the fire resistance of the epoxy resin. In turn, eugenol glycidyl ether (GE) was used as a diluent of epoxy ester resins during the vacuum infusion process of epoxy composites with the glass fiber. Eugenol-based epoxy resin was used to make composites with carbon fiber with enhanced thermomechanical properties. Likewise, resins such as bismaleimide resin, phthalonitrile resin, and palm oil-based resin have been used for the production of composites with eugenol derivatives.

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Tuohedi, Nuerjiamali, and Qingyue Wang. "Preparation and Evaluation of Epoxy Resin Prepared from the Liquefied Product of Cotton Stalk." Processes 9, no. 8 (August 16, 2021): 1417. http://dx.doi.org/10.3390/pr9081417.

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Liquefaction of waste lignocellulosic biomass is a viable technology for replacing fossil fuels and meeting sustainable development goals. In this study, bio-based epoxy resins were prepared from polyhydric-alcohol-liquefied cotton stalk by glycidyl etherification. The cotton stalk was liquefied in a polyethylene glycol/glycerol cosolvent under H2SO4 catalysis. Epon 828 and cotton-stalk-based epoxy resins could be cured using methylhexahydrophthalic anhydride as the curing agent, and the curing process was exothermic. The thermal properties and tensile strength of cured resins were investigated to examine the effect of adding cotton-stalk-based resin on the performance of the copolymerized epoxy resin. Further, the liquefied-cotton-stalk-based epoxy resin was blended with Epon 828 at different ratios (10, 20, and 30 mass%) and cured with a curing agent in the presence of 2-methylimidazole catalyst. An increase in the peak temperature and a reduction in the heat of curing and activation energy of the Epon 828 epoxy resin was observed with increasing content of the cotton-stalk-based epoxy resin. The tensile strength (35.4 MPa) and elastic modulus (1.5 GPa) of the highly crosslinked cotton-stalk-based epoxy resin were equivalent to those of the petroleum-based epoxy resin Epon 828.

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MIHU, Georgel, Claudia Veronica UNGUREANU, Vasile BRIA, Marina BUNEA, and Rodica CHIHAI PEȚU. "The Mechanical Properties of Organic Modified Epoxy Resin." Annals of “Dunarea de Jos” University of Galati. Fascicle IX, Metallurgy and Materials Science 43, no. 3 (September 15, 2020): 10–14. http://dx.doi.org/10.35219/mms.2020.3.02.

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Epoxy resins have been presenting a lot of scientific and technical interests and organic modified epoxy resins have recently receiving a great deal of attention. For obtaining the composite materials with good mechanical proprieties, a large variety of organic modification agents were used. For this study gluten and gelatin had been used as modifying agents thinking that their dispersion inside the polymer could increase the polymer biocompatibility. Equal amounts of the proteins were milled together and the obtained compound was used to form 1 to 5% weight ratios organic agents modified epoxy materials. To highlight the effect of these proteins in epoxy matrix mechanical tests as three-point bending and compression were performed.

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Li, Xiao Yan, Wen Jun Gan, Yuan Ren, Zheng Xi, Ye Wen Tang, and Sheng Jie Gu. "Effect of Molecular Weight on Phase Diagram of Epoxy/Polyetherimide-Siloxane Blends." Advanced Materials Research 189-193 (February 2011): 1127–31. http://dx.doi.org/10.4028/www.scientific.net/amr.189-193.1127.

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The cloud points of blends epoxy/polyetherimide-siloxane (PEI-Siloxane) without or with curing agent methyl tetrahydrophthalic anhydride (Me-THPA) after different curing time (1min, 2min, 3min) at 150oC were determined by optical microscope. The cloud point curve for uncured and cured after different time was then obtained from the experimental results with different composition. The effects of molecular weight of epoxy on phase diagram were discussed. The miscibility of blends will be taken into account in the toughing of epoxy resins by thermoplastic PEI-Siloxane copolymer later.

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Journal articles on the topic 'Epoxy resins Physiological effect'

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