Strength Of Resin Research Articles

Influence of home bleaching regimen on microhardness and flexural strength of two contemporary composite resins - an in vitro evaluation.

This study was to compare and evaluate the effect of home bleaching on the microhardness and flexural strength of microhybrid and nanohybrid composite resins. The study samples were prepared using a custom-made silicon rubber mold. For microhardness evaluation, 40 disc-shaped specimens (4mm*2mm) were prepared and divided into 4 groups: GROUP A (n=10): microhybrid (GC Solaire X, GC Corporation) control group, GROUP B (n=10) nanohybrid (Tetric N Ceram, Ivoclar Vivadent) control group, GROUP C (n=10): microhybrid bleaching group, GROUP D (n=10) nanohybrid bleaching group. For flexural strength evaluation, 40 bar shaped specimens (25mm*2mm*2mm) were prepared. They were divided into 4 groups, GROUP 1 (n=10): microhybrid control group, GROUP 2 (n=10) nanohybrid control group, GROUP 3 (n=10): microhybrid bleaching group, GROUP 4(n=10) nanohybrid bleaching group. All the control groups were placed in artificial saliva and bleaching groups were exposed to home bleaching agent for 14 days according to manufacturer's instructions. The microhardness and flexural strength were evaluated for the respective specimens after 14 days and the data were statistically analyzed. Home bleaching regimen decreased microhardness of both microhybrid and nanohybrid composites whereas there was no significant effect on the flexural strength. Nanohybrid composites showed greater microhardness values before and after bleaching. Bleaching agents, irrespective of their concentration can decrease the microhardness of the composite resin samples, which raises a concern about replacement of these restorations due to the effects on physical and mechanical properties.

Effect of Multiwall Carbon Nanotubes on Tensile Strength of Cross Lap Joint

Abstract: This paper compares the tensile strength of an adhesively bonded single cross lap joint with and without the addition of multiwall carbon nanotubes (MWCNT) in the adhesive. Tensile strength analysis of adhesively bonded cross lap joint is done by applying pulling load which produces tensile stress at overlap between two substrates which joined together by using adhesive. Cross lap joint were created using Al-Al substrates. Five tests were performed on Al-Al substrates with and without the addition of MWCNT in the adhesive for each specimen. MWCNT filler particles increase the toughness and strength of epoxy resin when compared to epoxy resin that does not contain MWCNT. MWCNT fill epoxy resin increases toughness and resists crack formation, increasing the interface strength between two substrates.

Mechanical and Biocompatibility Properties of 3D-Printed Dental Resin Reinforced with Glass Silica and Zirconia Nanoparticles: In Vitro Study.

This study aimed to assess the mechanical and biocompatibility properties of dental resin reinforced with different nanoparticle additives. Temporary crown specimens were 3D-printed and grouped based on nanoparticle type and amount, including zirconia and glass silica. Flexural strength testing evaluated the material's ability to withstand mechanical stress using a three-point bending test. Biocompatibility was tested using MTT and dead/live cell assays to assess effects on cell viability and tissue integration. Fractured specimens were analysed using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) for fracture surface examination and elemental composition determination. Results show that adding 5% glass fillers and 10-20% zirconia nanoparticles significantly improves the flexural strength and biocompatibility of the resin material. Specifically, the addition of 10%, 20% zirconia, and 5% glass silica by weight significantly increases the flexural strength of the 3D-printed resins. Biocompatibility testing reveals cell viabilities greater than 80% in all tested groups. Reinforced 3D-printed resin holds clinical potential for restorative dentistry, as zirconia and glass fillers have been shown to enhance mechanical and biocompatibility properties of dental resin, making it a promising option for dental restorations. The findings of this study may contribute to the development of more effective and durable dental materials.

Developing carbon dots as green modifiers for improving the bonding performance of low-molar-ratio urea-formaldehyde resin

Reducing formaldehyde-to-urea molar ratio is conducive to improving environmental-friendliness of urea-formaldehyde (UF) resin-bonded wooden products, but at the expense of bonding performance, such contradictoriness is intrinsically due to the decreased cohesion of resin polymer structures. In this study, we proposed a novel strategy to enhance the bonding performance of low-molar-ratio UF resins by use of carbon dots (CDs) as green modifiers. Taking advantages of surface-contained plentiful carboxyl and hydroxyl groups, the synthesized CDs could generate strong physicochemical interactions with polymer segments and further improve cohesion of resin matrix. The optical microrheology demonstrated that the microscopic viscoelasticity of CDs-modified UF resin was increased as increasing of CDs content due primarily to the formation of strong hydrogen bonding interactions between CDs and resin polymers. Based on the analysis for curing behavior, the polycondensation reactivity of resin oligomers was almost free from the interaction or connection between CDs and polymer segments. Furthermore, as confirmed by nanoindentation technology, the physicochemical interactions formed between oxygenous functional groups of CDs and polymer matrices could improve the cohesion of resin after curing reaction, thus resulting in the enhanced micromechanical strength of wood-resin interphase and further bonding strength of resin at macroscopic level. Remarkably, this reinforcing effect imparted by CDs resulted in the tensile shear strength of plywood increased to 0.96 MPa, which was 77.8% increase in comparison to the panels bonded with unmodified resin and largely exceed the requirement given by national standard (0.7 MPa for plywood type Ⅱ). Taken together, this work demonstrated that the synthesized CDs are efficient and provided a potential platform for improving the bonding performance of low-molar-ratio UF resins.

Shear bond strength of dual-cured resin cements on zirconia: The light-blocking effect of a zirconia crown

The presence of restorative material between resin cement and the light-curing unit can reduce light transmission. This study aimed to evaluate the effect of the light-blocking effect of zirconia crown on shear bond strength (SBS) between three dual-cured resin cements and the zirconia surface. Sixty zirconia specimens were prepared and divided into three groups according to the type of resin cement [RXU (RelyX Ultimate); SC2 (SmartCem2); MEC (Maxcem Elite Chroma)]. Each group was further divided into two subgroups, with or without a 1-mm-thick zirconia crown (n=10). The specimens were light-cured from five different directions for 20s each. All specimens were thermocycled 5000 times and subjected to SBS testing, followed by scanning electron microscope examination. The presence of a 1-mm-thick zirconia crown had no significant effect on the SBS in all resin cements. However, the SBS was significantly affected by type of resin cement. RXU showed the highest SBS (8.35MPa with crown; 8.57MPa without crown), followed by SC2 (5.48MPa with crown; 5.57 without crown) and then MEC (3.37MPa with crown; 4.04MPa without crown. Fractured surfaces exhibited varying degrees of mixed failure patterns. A 1-mm-thick zirconia crown material between the light source and the dual-cured resin cement did not significantly influence the SBS of the resin cements on the zirconia substrates. RXU exhibited the highest SBS regardless of zirconia crown coverage. With sufficient light-curing, dual-cured resin cements can be a good choice for zirconia crown cementation.

Prewarming effect on adaptation, porosities, and strength of a composite resin

Warming composite resin before insertion to reduce viscosity is advocated for improving adaptation and reducing voids. This study evaluated how prewarming altered porosities, adaptation, and strength.Twenty composite restorations were placed in 2 increments in typodont teeth with a large Class II preparation. The composite was either at room temperature (control) or prewarmed to 68 °C (n = 10/group). Each increment was light-cured for 20s. After 24h, the restored teeth were sectioned and imaged under a stereomicroscope. Examiners ranked the quality of adaptation to walls and between increments, and the presence of voids on a 0–3 scale. Results were statistically analyzed using Mann-Whitney U Test. Diametral tensile strength of monolithic or incrementally-filled composite cylinders (6 mm diameter × 4 mm height; n = 10/group) made with room temperature or prewarmed composite were tested at 0.5 mm/min. Strength results were analyzed using ANOVA statistics followed by pairwise comparisons.Restorations made with prewarmed composite had significantly fewer large voids and better adaptation to cavity walls and between layers (P < 0.05). Strength of prewarmed composite was higher than room temperature composite, and was significantly higher in monolithic specimens (P < 0.05).It was concluded that prewarming conventional composite can improve its handling, making it handle more like a flowable composite without jeopardizing physical properties. The prewarmed composite was found to have better adaptation and fewer voids, and attained higher strength than composite that was not prewarmed.

High-performance green composites made by cellulose long filament-reinforced vanillin epoxy resin

Developing high-performance composite materials from biobased resources is paving the path toward sustainability. This paper reports cellulose long filaments (CLFs)-reinforced Vanillin Epoxy (VE) green composite developed through vacuum-assisted resin transfer and compression molding techniques. The proposed green composite combines the strong and tough cellulose long filaments with the thermally stable and hydrophobic biobased VE resin. The reinforcement with CLFs improved the flexural strength and flexural modulus of neat biobased VE resin remarkably by 135.1% and 542.8%. The green composite possessed a Tg of 144 °C and a water contact angle (WCA) of 96.4o, demonstrating good thermal stability and hydrophobic properties. SEM and FTIR results showed a strong interaction between CLFs and biobased VE epoxy resin. The above characteristics make the proposed green composite a robust material for environmentally friendly and high-performance structural applications.

Nanocurcumin Release from Self-Cured Acrylic Resins; Effects on Antimicrobial Action and Flexural Strength.

The placement of orthodontic appliances into the oral area can lead to infection, inflammatory and gingival collapse. Using an antimicrobial and anti-inflammatory material in the matrix of orthodontic appliance may help to reduce these issues. This study aimed to assess the release pattern, the antimicrobial action and the flexural strength of self-cured acrylic resins after adding different weight percentages of curcumin nanoparticles (nanocurcumin). In this in-vitro study, 60 acrylic resin samples were divided into five groups (n = 12) based on the weight percentage of curcumin nanoparticles added to the acrylic powder (0 for control, 0.5, 1, 2.5, and 5%). Then, the dissolution apparatus was used for the release assessment of nanocurcumin form the resins. For antimicrobial action assessment, the disk diffusion method was used and a three-point bending test was performed with a speed of 5 mm/min to determine the flexural strength. Data were analyzed using one-way analysis of variance (ANOVA) and Post-Hoc Tukey tests (with p < 0.05 as significant level). The microscopic images showed the homogeny distribution of nanocuricumin in self-cured acrylic resins in varied concentrations. The release pattern showed a two-step release pattern for all concentrations of nanocurcumin. The one-way ANOVA outcomes indicated that adding curcumin nanoparticles to self-cured resin increased the diameter of the inhibition zones for the groups against Streptococcus mutans (S. mutans) significantly (p < 0.0001). Additionally, as the weight percentage of curcumin nanoparticles increased, the flexural strength decreased (p < 0.0001). However, all strength values were higher than the standard value (50 MPa). No significant difference was detected between the control group and the group with 0.5 percent (p = 0.57). Considering the proper release pattern and the potent antimicrobial activity of curcumin nanoparticles, then the preparing self-cured resins containing curcumin nanoparticles can be beneficial for antimicrobial aims without damaging the flexural strength to use in orthodontic removable applications.

Fabrication of layered double hydroxide@ferric decorated polyphosphazene hybrid architecture towards simultaneously improved fire safety, smoke suppression and mechanical strength of epoxy resin

The requirement of high-efficiency flame retardants for epoxy (EP) resin is urgent due to its high flammability. Herein, a hybrid architecture (LDH@PZE-Fe) was synthesized via intercalation by surfactant and interfacial modification by ferric decorated and amino groups-containing polyphosphazene (PZE) to enhance the fire safety and smoke suppression of EP. With the introduction of 2.5 wt% LDH@PZE-Fe, EP/LDH@PZE-Fe achieved UL-94 V-0 rating with a LOI value of 27.5%. Moreover, EP/LDH@PZE-Fe performed superiorly in inhibiting the release of heat and smoke. Such high-efficiency flame-retardancy was ascribed to the combined action both in condensed and gaseous phases, which was verified by analyzing the morphology and structure of the char layer and the composition of pyrolysis gases. Additionally, EP/LDH@PZE-Fe exhibited satisfactory impact strength and enhanced glass transition temperature due to the good compatibility of LDH@PZE-Fe with EP matrix. Therefore, the flame-retardant EP composites had potential applications as highly flame-retardant materials.

Impact Strength of Various Types of Acrylic Resin: An In Vitro Study.

The aim of this study is to evaluate and compare the impact strength of conventional acrylic resin, high-impact acrylic resin, high-impact acrylic resin reinforced with silver nanoparticles, and high-impact acrylic resin reinforced with a zirconium oxide powder. A total of 60 samples were prepared of dimensions 60 mm length × 7 mm width × 4 mm thickness to test impact strength. Machined stainless steel dies of the same dimension were used to form molds for the fabrication of these samples. Of 60 samples, 15 samples were prepared each from conventional acrylic resin (Group A1), high-impact acrylic resin (Group A2), acrylic resin reinforced with silver nanoparticles (Group A3), and acrylic resin reinforced with zirconium oxide powder (Group A4). Izod-Charpy pendulum impact testing machine was used. The impact strength of group A1 was in the range of 2.83-3.30 kJ/m2 (M = 3.12 kJ/m2, SD = 0.16), group A2 was in range of 5.10-5.78 kJ/m2 (M = 5.51 kJ/m2, SD = 0.18), group A3 was in range 3.18-3.56 kJ/m2 (M = 3.37 kJ/m2, SD = 0.11), and group A4 was in range 7.18-7.78 kJ/m2 (M = 7.5 kJ/m2, SD = 0.18). Statistical analysis using one-way ANOVA and t-test revealed significant differences (p < 0.001). High-impact acrylic resin reinforced with zirconium oxide powder has the highest impact strength. This research sheds light on the usefulness of novel filler materials in clinical prosthodontics.

Tensile Bond Strength of Hypoallergenic Acetal Resin and Heat-cured Acrylic Resin to Soft Denture Liners

Tensile Bond Strength of Hypoallergenic Acetal Resin and Heat-cured Acrylic Resin to Soft Denture Liners

Impact Strength Enhancement of PMMA base Denture Material by Fibre Addition

Prostheses used temporarily are flexible based on function. Given the paucity of empirical knowledge flexural strength of temporary resins, choosing the right material for their manufacturing is challenging. Dentures have been reinforced with partial fibres both during the production process and during repairs. Polymer's fiber-rich phase in the denture base can either form a distinct structure or the reinforcing fibres can be dispersed equally throughout the material. In this work, the static three-point flexural strength and modulus of denture base polymer reinforced with various fibre reinforcements were determined. PMMA base material can currently be strengthened by adding fibre reinforcement. The creation of bar-type specimens complied with standard 27 of the American National Standards Institute and the American Dental Association. After being immersed in artificial saliva at 37°C for 10 days, the specimens were broken under 3-point loading with a crosshead speed of 0.75 mm/min in a universal testing machine. The highest breaking weights were expressed in Newton’s. The mean flexural strengths were measured in MPa (n = 10 per group). Results were compared using variance analysis and Duncan's multiple ranges testing (P.05). Impact strength of The Glass and Natural fibre (Jute, Sugarcane, Banana etc.) group with 1% and 0.5% composition respectively composition have the maximum value. This group shows the maximum value of flexural strength, compression strength and tensile strength. The findings imply that fibres that are impregnated or re-impregnated strengthen the denture base polymer more than fibres that are not impregnated. When compared to the same amount of fibre reinforcement placed on the compression side, the fibre reinforcement applied on the tensile side produced much higher values for flexural strength and flexural modulus.

The potential of salivary albumin to degrade composite resin.

The purpose of this study was to evaluate whether artificial saliva formulations with different concentrations of albumin affected the surface roughness, flexural strength and microhardness of a composite resin. Specimens (25x2x2mm) of a nanofilled composite (Filtek Z350XT, 3M/ESPE) were prepared and analyzed for average surface roughness (Ra/pm). The specimens were then allocated to 6 groups (n=30), to be treated with different salivary albumin concentrations: 0, 10, 50, 100, 200, 400 pg/mL. The specimens were stored in their respective artificial saliva groups, half of them for 24 h and the remainder for 180 days (artificial saliva renewed weekly), after which they were submitted to a new Ra reading, and tested for three-point flexural strength (FS, MPa). The specimens stored for 180 days were analyzed for Knoop microhardness (KH, Kg/mm2). Data were submitted to two-way ANOVA (Ra and FS) and one-way ANOVA (KH). Although Ra increased (p < 0.001) and FS decreased (p < 0.001) from 24 hours to 180 days of storage, the albumin concentration did not significantly affectRa (p = 0.168), FS (p = 0.477) or KH (p = 0.378). The esterolytic action of albumin did not increase the artificial-saliva-induced hydrolytic degradation of the composite resin.

Mechanical and Corrosion Protection Characteristics of CNTs/epoxy resin Nanocomposite Coating on Buried API 5L X65 Steel Storage Tank

The storage of petroleum products in buried metal tanks to ensure safety is common practice. However, the integrity of these tanks could be compromised by soil corrosion with economic and environmental consequences. This study examines carbon nanotubes mechanical and anti-corrosive capabilities (CNTs) and epoxy resin coating on steel tanks. The presence of corrosive ions, resistivity, and pH values were all tested in the soil sample. CNT was mixed in proportions of 1.5, 2.5, 3.5 and 4.5 weight percent of epoxy resin to create the coatings. The morphology of uncoated steel, epoxy, and CNTs/ epoxy resin-coated steel specimens was studied using high-resolution scanning electron microscopy (HRSEM) equipment with energy dispersive x-ray spectroscopy (EDX). Electrochemical impedance spectroscopy (EIS) was used for corrosion analysis, and the morphological result was established. The average ions content soil samples showed 272 mg/kg chloride, 467.20 mg/kg sulphate and 167.40 Ω-m for the average resistivity value. The sample’s pH was acidic because it fell within 6.11–7.48. The tensile strength, hardness, and tensile modulus of epoxy resin with CNTs increase with CNTs. The addition of 3.5% CNTs has the best effect on the mechanical strength of the composite. The nanocomposite coatings exhibited considerably superior conductors, according to the EIS investigation. Thus, the hybrid of epoxy and CNTs increases the hydrophobicity of the coated surface.

A Comparative Evaluation of the Shear Bond Strength of Veneering Ceramics and Composite Resin to Zirconia Core: An In Vitro Study

A Comparative Evaluation of the Shear Bond Strength of Veneering Ceramics and Composite Resin to Zirconia Core: An In Vitro Study

Comparative Evaluation of Shear Bond Strength of Glass Ionomer Cement, Composite and Compomer in Primary Teeth: An In Vitro Study

Background: Because the main dislodging pressures at the tooth restoration interface have a shearing effect, shear bond strength is crucial for the restorative material clinically. Therefore, greater shear bond strength suggests improved material to tooth bonding. Glass ionomer cement and composite is the most popularly used restorative material. Composite resins have better mechanical properties and esthetics than many other types of cement, but they need bonding agents as they are hydrophobic and hence fail to adhere to the teeth. Compomers are polyacid modified resin composites. Compomer and composite resin have similar physical properties, as they are thought to bond to dentin by micromechanical bonding. As resin composites are used in this, the polymerized acid monomer shows acidity when it comes in contact with the saliva and there is a reaction of fluoride-containing basic glass resulting in the cariostatic effect. Aim: The purpose of this study was to evaluate and compare the shear bond strength of Glass Ionomer Cement (Fuji IX GP), Composite Resin (Filtek Z-250) and Compomer, (Compoglass, Ivoclar). Material and Method: An in-vitro, experimental study was conducted on 30 freshly extracted over-retained deciduous molars. Samples were randomly divided into three groups depending on the material to be used. Flat dentinal surface on tooth was prepared over which restorative materials were placed. The prepared specimen was subjected to shear test and the value obtained was compared. Descriptive statistical analysis was performed to calculate the mean shear bond strength of each group. Result: It was observed from the study that the composite resin had the highest shear bond strength value (17.13 ± 1.54), followed by compomer (11.32 ± 1.05) whereas GIC showed the least shear bond strength (6.56 ± 0.87). Conclusion: It was concluded that composite restorative materials show higher shear bond strength than glass ionomer cement and compomer in primary molars, but shear bond strength of compomer was higher than that of glass ionomer cement.

Bonding effect of a Zr/Si coating prepared on zirconia using a sol-gel method

Statement of problemZirconia has been widely used as a dental prosthetic material. However, bonding to zirconia is challenging, and whether a Zr/Si coating would improve bonding is unclear. PurposeThe purpose of this in vitro study was to prepare a Zr/Si coating on zirconia ceramics using a sol-gel method and to determine whether the bonding to resin is improved. Material and methodsPresintered zirconia specimens were prepared and divided into 5 groups: 4 experimental groups with ratios of the binary sol-gel precursor (zirconium oxychloride/tetraethoxysilane) set as 2:1 (Z2), 1:1 (Z1), 0.5:1 (Z0.5), and 0.25:1 (Z0.25) and Group C as the control group. In addition to surface roughness measurements, scanning electron microscopy (SEM), energy dispersion spectroscopy (EDS), and X-ray diffraction (XRD) were carried out to characterize the surface. Each group was divided into 2 subgroups according to whether a silane coupling agent was applied. Half of the bond specimens were stored in deionized water for 24 hours; the remaining half were aged using 5000 thermocycles. The shear bond strength (SBS) of resin bonded to specimens was tested for the initial and durable bond strength, and the bonding interface was also observed by SEM after debonding. Data were subjected to 1-way ANOVA and the post hoc Tukey honestly significant difference test (α=.05). ResultsThe Zr/Si coating formed on zirconia ceramics. Z0.5 had the greatest mean ±standard deviation roughness (2.13 ±0.15 μm) and had the highest silicon content (21.7 ±0.21%). t-ZrO2, m-ZrO2, c-SiO2, and ZrSiO4 were detected by XRD in Z1. The SBS values were decreased by aging but were significantly increased by Zr/Si coating, especially for Z0.5, with the application of silane (initial: 22.92 ±2.79 MPa; aged: 9.91 ±0.92 MPa). ConclusionsThe Zr/Si coating significantly improved the initial and aged bond strength, and the optimal Zr/Si ratio of the sol-gel appeared to be 0.5:1.

Flexural strength acrylic resin heat cured for denture base in soaking mouthwash containing siwak

Background: Teeth have an important role in a person, the most common cause of tooth loss is caries and periodontal disease. Tooth loss can be overcome by making dentures, removable denture components consist of dental elements, clasps, and bases. The denture base is part of denture that rests on soft tissues of oral cavity and is where denture elements are attached. One of the important mechanical properties for denture bases is flexural strength. Acrylic resin denture base material has disadvantage that it absorbs liquid and is porous so that food debris can settle and become a place for microorganisms to grow and multiply. This study aims to determine flexural strength of heat cured acrylic resin for denture base in immersing mouthwash containing siwak Method: this laboratory experiment used 12 linear specimens with a size (64 x 10 x 3.3 mm) ± 0.2 mm in accordance with ISO 20795-1:2013 which were divided into 2 groups, the first group was immersed in aquabidest (control), the second group was immersed in mouthwash containing siwak for 7 days. The data obtained were then tested using the Independent T-test Result: There was no significant difference (p &gt; 0.05) in the flexural strength of heat cured acrylic resin Conclusion: From the research, there is no effect flexural strength of heat cured acrylic resin in soaking mouthwash containing siwak. The effect of mouthwash containing siwak on the flexural strength of heat-cured acrylic resin was not significant.

Evaluation of Bond Strength of Resin and Non-resin Cements to Different Alloys.

A strong metal-cement bond is one of the many factors that contribute to the clinical success of a fixed prosthesis. Even though it is crucial to create ideal resistance and retention forms during tooth preparation, dental cement must be strong enough to hold the restoration in place in the mouth.The present study set out to evaluate and compare the binding strength of resin modified glass ionomer cement, resin cement, and glass ionomer cement to four different metal alloys: titanium alloy, cobalt-chromium (Co-Cr) alloy, nickel-chromium (Ni-Cr) alloy, and noble metal alloys (silver palladium based). Two hundred and forty metal alloy specimenswere created; these were fashioned from (i) a noble metal alloy (silver-palladium based), (ii) a titanium alloy, (iii) a cobalt-chromium alloy, and (iv) a nickel-chromium alloy. A universal testing machine was used to perform the shear test, and statistical analysis of the result was done using a two-way analysis of variance (ANOVA) test and Bonferroni test. Results:The Co-Cr alloy among the cement under investigation had the highest mean value of shear bond strength of 8.06 MPa, whereas a noble metal alloy had the lowest shear strength with a mean value of 5.36 MPa. The resin cement demonstrated the highest shear strength with a mean value that was higher than the other two types of cement. The shear bond strength of the examined samples was significantly affected by the interaction of the alloy and cement, according to the two-way ANOVA test (p=0.001). The results demonstrate that resin cement offers a stronger bond, followed by resin-modified GIC and GIC. The Co-Cr alloy had the highest shear bond strength, followed by Ni-Cr, titanium, and noble metal alloy which showed significantly lower shear strength than the other three alloys.

Fluorination Treatment and Nano-Alumina Concentration on the Direct Current Breakdown Performance &amp; Trap Levels of Epoxy/Alumina Nanocomposite for a Sustainable Power System

Epoxy resin is extensively used in gas insulated switches as a renewable energy coating due to its exceptional insulation, mechanical characteristics, and environmental friendliness. The higher resistivity of the epoxy resin causes numerous surface charges to accumulate on the surface of the epoxy resin as a result of carrier injection due to the high DC electric field, which may cause insulation failure of the power transmission system. In this study, various concentrations of epoxy resins blended with nano-alumina (nano-Al2O3) at 0 wt%, 1 wt%, 3 wt%, and 5 wt% were created. Afterwards, the epoxy resin and Al2O3 nanocomposites were fluorinated by utilizing a combination of F2 and N2 with a ratio of 20% F2 at 0.05 MPa while maintaining the temperature at 40 °C. In order to improve dispersion, nano- Al2O3 was treated with a silane coupling agent called γ-aminopropyltriethoxysilane (KH550). Additionally, infrared spectroscopy based on the Fourier transform was used to investigate the structure of chemical bonds. Furthermore, the changes in the molecular chains were verified by the FTIR spectra. The DC breakdown strength of epoxy resin\Al2O3 nano-composites showed that breakdown strength significantly improved after gas-phase fluorination. Moreover, 1 wt% nano- Al2O3 showed a higher breakdown strength. The fluorinated layer had a charge-suppressing effect, reducing the charge injected into the polymer matrix of the epoxy-resin matrix and increasing its DC breakdown capability. Thermally stimulated current (TSC) measurements indicate that epoxy resin’s trap energy and trap density are altered by nano- Al2O3 incorporation and fluorination treatment (gas-phase). It was also observed that introducing nano- Al2O3 at a lower concentration (e.g., 1 wt%) can hinder the growth of space charge in the polymer matrix of the epoxy resin, thus enhancing the deep traps’ energy. Furthermore, a fluorination layer containing a strong polarization of C-F bonding would seize the charge injection from electrodes, thus decreasing the conductivity and suppressing the charge injection.