Pure Resin Research Articles

The Effect of p-Toluenesulfonic Acid and Phosphoric Acid (V) Content on the Heat Resistance and Thermal Properties of Phenol Resin and Phenol-Carbon Composite

This work presents the results of research on the influence of the amount of p-toluenesulfonic acid and phosphoric acid (V) added to the phenol-formaldehyde resin (pH 7.3–7.8) on its thermal properties and on the phenol-formaldehyde-carbon composite produced on its basis. This material undergoes pyrolysis under high temperature. The addition of a catalyst to the phenol-formaldehyde resin affects its curing rate and degree of cross-linking, but how it affects the thermal properties of the resin depending on the temperature is the subject of this work. This article presents the results of thermal tests for phenol-formaldehyde resin and phenol-formaldehyde-carbon composite. It was examined how the content of the catalyst used during the production process affects the individual thermal parameters of the mentioned materials. The results include experimental tests of thermal diffusivity with uncertainty (±3%), specific heat capacity (±2.5%), thermal expansion with resolution 2 nm analyzed in the temperature range −40–115 °C and thermogravimetric TG/DTA analysis with resolution 0.03 µg in the temperature range from room temperature (RT = 23 °C) to 550 °C. Individual thermal tests showed changes in the thermal properties caused by changes in the catalyst content of the tested materials and the influence of the addition of carbon fibers on the properties of the composite compared to the pure phenol-formaldehyde resin. It was found that there is a certain maximum level of catalyst weight fraction at which the greatest decrease in thermal diffusivity occurs. In the case of phenolic-formaldehyde-carbon composite at −40 °C, an increase in catalyst weight fraction from 2 to 4 wt% caused a decrease in thermal diffusivity by 18.2%, and for phenol-formaldehyde resin, it was 2.8% with an increase in catalyst fraction from 4 to 10 wt%.

Application of Olivine Powder as a Filler for Silicone Pressure-Sensitive Adhesives

In this work, new self-adhesive materials were obtained based on cross-linked silicone self-adhesives obtained by modifying the composition with the addition of a silicon filler, olivine. Silicone pressure-sensitive resin DOWSIL 7358 was used as a basis and modified with various amounts of olivine. New materials (self-adhesive tape samples) were characterized in terms of peel adhesion, tack, cohesion at room and elevated temperatures, SAFT test (shear adhesion failure temperature), pot life (storage stability), and shrinkage (dimensional stability). During the tests, an increase in thermal resistance (>225 °C) and a drastic reduction in shrinkage values (below 0.5%) were noted for all modified samples tested. All tests were performed in compliance with international standards, e.g., FINAT FTM 1, FINAT FTM 8, FINAT FTM 9, FINAT FTM 14, and GTF 6001. This allows us to conclude that the new material has significant application potential due to the good performance results. The results of adhesion and tack were in ranges accepted in the PSA industry, cohesion was kept at an unchanged level (above 72 h), and a great increase in the thermal resistance was observed (from 147 °C for pure resin to high above 225 °C for even the smallest additions of the olivine powder. Moreover, the shrinkage of prepared adhesive films was reduced significantly. In the available literature, there are no references to the modification of adhesives using powdered silicon minerals of natural origin, which is a novelty due to their higher bulk density compared to commercial powdered silicon fillers.

Physio-Mechanic and Microscopic Analyses of Bioactive Glass-Based Resin Infiltrants.

This study aimed to investigate the efficacy and durability of bioactive glass-based dental resin infiltrants. Resin infiltrants were formulated by combining photoinitiated dimethacrylate monomers with three variations of bioactive glass: 45S5 Bioglass (RIS), boron-substituted (RIB), fluoride-substituted (RIF), and pure resins (PR), whereby TOOTH group (TH) and ICON (CN) served as commercial control groups. Teeth samples were prepared, and experimental and control infiltrants were applied on demineralized human-extracted teeth. All the samples were subjected to immersion in artificial saliva and pH cycling for 30 days. The samples from another group underwent tooth brushing simulation for 9600 cycles. Following artificial saliva immersion, the samples' hardness values showed that RIB had the highest values (318.44 ± 3.83) while PR (212.52 ± 9.02) had the lowest values. After immersing into the pH cycling solution, the RIF showed the highest hardness (286.86 ± 5.11), while the lowest values for the CN (143.76 ± 3.50). After the tooth brushing simulation, the teeth samples with RIB showed maximum microhardness values (312.06 ± 16.30) and the weakest for the TH (189.60 ± 6.43). The commercial and experimental enamel resin infiltrants showed almost similar results overall, with RIB demonstrating better microhardness and comparable surface roughness. In contrast, RIF proved more resistant to pH cycling, exhibited higher microhardness, and performed better in surface roughness analysis. These findings suggest that resin infiltrant materials, especially RIF, have promising potential for effectively and esthetically managing white spot lesions.

Hierarchical curing mechanism in epoxy/bismaleimide composites: Enhancing mechanical properties without compromising thermal stabilities

It remains a considerable challenge to enhance mechanical properties without sacrifice of thermal properties in epoxy-based materials. In this study, epoxy/bismaleimide (EP/BMI) composites were synthesized via a melting blend technique using 4,4′-diaminodiphenylsulfone as the curing agent. It is found that there is a unique hierarchical curing mechanism in EP/BMI systems, including (i) respective curing of EP and BMI monomer, (ii) copolymerization between EP prepolymer and BMI monomer, (iii) homopolymerization of EP prepolymer and BMI oligomer. Via the hierarchical copolymerization, EP and BMI are compatible without phase separation phenomenon. The copolymerization concurrently improved the composites’ resistance to deformation under stress and restricted the thermal mobility of the polymer chains upon heat. Compared to pure EP resin, EP/BMI composite (4:1) shows a flexural strength of 133.6 MPa, tensile strength of 106.4 MPa and toughness of 3.6 MJ/m3 respectively, increased by 20.7 %, 36.4 % and 45.0 %. Meanwhile, Tg and Yc were also improved by 10.3 ℃ and 12.3 % in EP/BMI composite. Furthermore, the mechanical and thermal properties of the EP/BMI composites can be efficiently tailored by curing conditions and EP:BMI molar ratios. This discovery provides a significant benchmark for the design of composite material and to expand the application horizons for both EP and BMI materials.

The influence of CuxS particles on the thermal decomposition of anion exchangers

Due to the versality, surface imperfections and diverse redox chemistry of CuxS, hybrid ion exchangers (HIXs) containing these particles are an interesting object of research, including thermal transformation. The composite materials used for testing were strongly basic anion exchangers, with macroreticular (M) and gel-type structure (G), containing in the poly (styrene/divinylbenzene) skeleton fine particles of covellite/brochantite (M1), covellite (M2), covellite/digenite/djurleite (G1) and covellite/digenite (G2). The prepared HIXs contained 12–16 mass% S + Cu. They were subjected to thermal analysis under air and N2 to identify the role of the inorganic phase in decomposition of the polymeric phase. The results were discussed on the basis of the TG/DTG curves and X-ray diffraction (XRD) patterns of the solid residues (CuO after combustion, carbon/Cu2S after pyrolysis). It was found that CuxS in the resin phase exhibited oxidative activity promoting the combustion process. The polymeric skeleton of HIXs decomposed in air at a much lower temperature compared to pure resins (400 vs 600 °C). The TG/DTG curves had a model shape, three separate conversions occurring in a narrow temperature range, which indicated sequential decomposition. The low consumption of hydrogen for the reduction of CuxS to Cu2S during pyrolysis was not conducive to condensation of alkyl radicals and increase of the mass of carbon matter. The results advance the understanding of the effect of copper/sulfur-containing fine particles on the thermal decomposition of anion exchanger and can be useful in preparation of multifunctional carbon-containing composite materials.

Vat photopolymerization for thermal energy storage applications using encapsulated phase change material suspended in photocurable resin

A novel approach to additively manufacture latent heat thermal energy storage heat exchangers through the development of microencapsulated phase change material (MEPCM) suspensions in photocurable resin for vat photopolymerization (VPP) 3D printing is presented. Using MEPCM addresses the leakage risks that have typically been associated with PCMs and subsequently makes the particulates a suitable additive for VPP 3D printing. In the current study, VPP was employed to fabricate functional composites with varying MEPCM mass fractions for thermal, rheological, microstructure, and chemical characterization. Microstructure visualization was conducted to assess the overall distribution of MEPCM within the 3D printed samples and to confirm the structural integrity of the encapsulated particles after printing. The influence of the base resin viscosity was explored by investigating two photocurable resins with different viscosities—a high-tensile UV photopolymer and an ABS-like resin—during the printing process. Thermal properties, such as latent heat of fusion, phase-change temperature, thermal conductivity, and decomposition temperature of the 3D printed samples were determined. Rheology was used to observe the effect of varying shear rates on the MEPCM-resin mixtures to identify the optimal viscoelastic properties for VPP 3D printing. It was determined that the ABS-like resin was able to contain a larger amount of PCM (40 wt%) while maintaining printability due to the lower viscosity of the corresponding pure resin. The 40 wt% MEPCM composite exhibited an average viscosity of 18,817 cPs, a maximum latent heat of fusion of 54.12 kJ/kg, and a 12.4% reduction in thermal conductivity compared to the pure polymer.

In-situ monitoring of multi-physical dynamics in ceramic additive manufacturing

Ceramic additive manufacturing is an innovative technology for developing complex ceramic structures, while a direct understanding of the physical phenomena occurring in sequential layers remains challenging, affected by the material design such as the presence of inorganic particles and their contents. This study provides a direct analysis of how the ceramic particles influence fabrication behavior utilizing an in-situ monitoring system. The force profile provides immediate feedback on fractures and geometric design, with the fluctuation in force directly corresponding to specific structural characteristics and stability during the fabrication. Furthermore, the multi-physical dynamics was investigated with a unit signal based on the effect of ceramic on the rheological-curing-mechanical behavior. For example, the mechanical behavior was characterized in real-time, as shown through an intensified peak of 6.6 kPa during the manufacturing of a ceramic composite, a 5.6 times increase compared to pure resin. The monitored data quantified the geometric dynamics and the multi-physical mechanism in real-time, achieved from the data on the overall fabrication status and the unit signal analysis of continuous manufacturing. This method can improve the reliability of ceramic additive manufacturing by providing insight into how ceramics impact fabrication behavior on sequential layers in real-time.

Preparation and Characterization of Graphene Oxide/Carbon Nanotube/Polyaniline Composite and Conductive and Anticorrosive Properties of Its Waterborne Epoxy Composite Coatings.

The organic coating on the surface is common and the most effective method to prevent metal materials from corrosion. However, the corrosive medium can penetrate the metal surface via micropores, and electrons cannot transfer in the pure resin coatings. In this paper, a new type of anticorrosive and electrically conductive composite coating filled with graphene oxide/carbon nanotube/polyaniline (GO/CNT/PANI) nanocomposites was successfully prepared by in situ polymerization of aniline (AN) on the surface of GO and CNT and using waterborne epoxy resin (WEP) as film-forming material. The structure and morphology of the composite were characterized using a series of characterization methods. The composite coatings were comparatively examined through resistivity, potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS), and salt spray tests. The results show that the GO/CNT/PANI/WEP composite coating exhibits excellent corrosion resistance for metal substrates and good conductivity when the mass fraction of GO/CNT/PANI is 3.5%. It exhibits a lower corrosion current density of 4.53 × 10-8 A·cm-2 and a higher electrochemical impedance of 3.84 × 106 Ω·cm2, while only slight corrosion occurred after 480 h in the salt spray test. The resistivity of composite coating is as low as 2.3 × 104 Ω·cm. The composite coating possesses anticorrosive and electrically conductive properties based on the synergistic effect of nanofillers and expands the application scope in grounding grids and oil storage tank protection fields.

Mechanical Characterization of Curaua Fiber/Babool Wood Particle Reinforced Polyester Hybrid Composite

Background: The researchers are in the situation to satisfy the demand for engineering materials by developing novel eco-friendly materials. The natural fiber composites are the substitutes for the synthetic material. Introduction: The mechanical properties of curaua fiber-reinforced polyester (CFRP) composites were investigated, as well as the effects of curaua fibre infusion with Babool Wood particles (BWP). Methods: The composite specimens were fabricated using a hand lay-up approach using varying amounts of curaua fibres (CF) and babool wood particles in a 1:1 ratio in order to test the tensile strength and flexural strength. Results: The results demonstrated that before weakening, the tensile strength and flexural strength of the composite samples rose by up to 40% for hybrid reinforcements. Comparing samples made of pure resin to those made of the composite at 40 weight percent (CF20/BWP20), the tensile and bending strengths of the composite are improved by 93.42% and 86.4%, respectively. Conclusion: The tensile and flexural modulus values of the hybrid composites increased by up to 50% fiber, but less successfully (CF25 and BWP25). The fracture mechanism of the shattered composite samples was examined using scanning electron microscopy.

Synthesis of rice‐granular bimetallic nickel/iron phyllosilicates to simultaneously lubricate and strengthen the epoxy‐based composites

AbstractTo improve the subpar lubricating performance of epoxy resin, this paper presents the preparation of a novel bimetallic phyllosilicate featuring a distinctive rice‐granular morphology, which incorporates nickel and iron metal cations through a facile hydrothermal process. These phyllosilicates were then integrated into the epoxy matrix to form composites. A comprehensive analysis of the target product validates the rationality of the synthesis strategy for the as‐prepared rice‐granular bimetallic nickel/iron phyllosilicate, demonstrating a homogeneous hierarchical structure with numerous tiny nanosheets of nickel/iron phyllosilicate grown in situ on the flat surfaces of the rice‐granular metal–organic frameworks. An adequate addition of nickel/iron phyllosilicates allows for excellent dispersion within the matrix and establishes strongly bonded interfaces, steadily increasing the elastic modulus and hardness. Notably, the average friction coefficients decrease from 0.515 for the pure resin to 0.450 for the composites when the filler content reaches 7%, indicating a significant solid lubrication effect. In contrast, adding just 1% nickel/iron phyllosilicate moderately improves wear resistance, elongation at break, and tensile strength. Furthermore, it was found that as the filler content increased, the weight loss rate was reduced by approximately 43.8%, while the residual char increased by 74.2%, significantly enhancing the thermal stability of epoxy composites at high temperatures. This study offers a promising approach to preparing self‐lubricated epoxy composites with favorable mechanical and thermal properties.Highlights NiFePS was successfully synthesized via a facile two‐step self‐polymerization. Excellent mechanical properties of composites could be achieved with low content of NiFePS. The friction coefficient and wear rate were lowered remarkably. The friction mechanism was solid lubrication.

Plasma-sprayed high entropy alloy coating with novel MoS2 /resin hybrid sealant: Tribological and corrosion characterization

Sealing treatment provides a strategy for the long-term performance of thermal spray coatings under actual working conditions. However, common sealants are mainly limited to improving the corrosion resistance of coatings, neglecting applications in more complex environments where they are subject to simultaneous corrosion and wear. Herein, a novel organic-inorganic hybrid composite sealant, composed of self-lubricating MoS2 nanoparticles and environmentally friendly waterborne silicone modified acrylic resin (WBS-ACR), was successfully prepared in the pores and micro-defects of plasma-sprayed HEA coatings by one-step hydrothermal method. The results indicate that MoS2 nanosheets are uniformly synthesized in resin materials through precursor hydrothermal reactions. The hybrid sealants are filled densely in the micro-defects of HEA coatings with a maximum penetration depth greater than 180 μm. The tribological and electrochemical results indicate that the hybrid sealant exhibits similar anti-wear performance, but two orders of magnitude lower corrosion currents than that of pure MoS2 sealant. In comparison to the pure resin sealant, the hybrid sealant retains its excellent corrosion resistance while increasing its wear resistance. The superior comprehensive performance of the novel organic-inorganic hybrid sealant could expand the application of thermal spray coatings into new fields.

(Alumina and graphene)/ PLA nanocomposites manufactured by digital light processing 3D printer

In this study, the variant effects of alumina and graphene reinforcing nanoparticle percentages on the tensile and wear properties of the nanocomposites, produced using digital light processing (DLP), were determined by employing SEM images of fracture and worn surfaces to introduce a hybrid (alumina + graphene)/PLA nanocomposite with desirable wear and mechanical properties. With the addition of alumina up to 2 wt%, the tensile strength was initially decreased exhibiting a rapid brittle fracture over the flat fracture surface. However, with a continued increase in the amount of reinforcing particles, the tensile strength eventually increased by 16% compared to the pure resin sample at 8 wt% of alumina while changing the fracture mode with plenty of cleavages accompanied by crack deflections. The specific wear rate in the 8 wt% alumina sample decreased by almost 62% compared to the pure resin sample. Graphene caused a significant drop in tensile strength due to the generation of cavities and porosities around the graphene agglomerates, but it greatly improved the wear properties, with the specific wear rate decreasing by almost 77% at just 1 wt%. Then hybrid nanocomposites of alumina and graphene reinforcements were produced with the aim of optimal tensile and wear properties. The 0.5% graphene +3.5% alumina improved the wear resistance and provided moderate tensile properties; however, the 1% graphene +3% alumina could not increase the wear resistance due to the weakening of graphene plates sticking to the polymer substrate.

High-output solid[sbnd]liquid triboelectric nanogenerator enhanced by the regulation of interfacial wettability

Triboelectric nanogenerators (TENGs), as a new strategy for harvesting energy from nature, have attracted widespread attention in the field of water droplet energy capture. As a friction layer material, the solidliquid electrification phenomenon of coatings has been studied. However, little attention is paid to the influence of the surface wettability of the coating itself on the electrical signal of the droplet generator. In this study, alkyl/phenyl pure silicone resin was utilized as a substitute for fluorine-containing polymer materials. This substitution not only mitigated the risk of environmental pollution from TENG friction materials but also resulted in varying wettability of the silicone resin coating through plasma and surface structure treatment. The droplet-based Double-electrode (D-TENG) and Single-electrode (S-TENG) coating-based triboelectric nanogenerators were fabricated. Through the integration of a high-speed camera and ammeter, the motion state of water droplets on surfaces with different wettability closely correlates with their charged behavior. This correlation is utilized to observe the motion state of water droplets on hydrophilic-hydrophobic surfaces in four stages: contact, spreading, contraction, and sliding. Under the double-electrode structure, as the water contact angle of the coating increased from 6.84° to 139.77°, the short-circuit current initially increased and then decreased, peaking at 466 µA when the contact angle was 98.48°, representing a 677-fold increase from the initial 0.689 µA. In the single electrode structure, the short-circuit current increased from 2.66 nA to 700 nA, indicating a 263-fold increase. Studying the varied wettability of the surface of silicone resin coating aids in comprehending the application of the coating material in solid-liquid friction electrification for energy collection. Furthermore, it offers insight into selecting appropriate coating materials for friction coatings in future applications.

Simulation of UV curing of photosensitive resins with phase change materials

Based on the mechanism of the resin polymerization reaction and free radical diffusion under UV irradiation, here, a mathematical model of the curing process was established for the mixture of photosensitive resin (PAA) and polyethylene glycol (PEG, as the phase change material), and the factor influencing the mechanical performance of the cured samples was analyzed. The yield stress (σs) of the pure resin sample can reach 50 MPa when the monolayer curing depth is 5 mm. σs decreases with the increase in the PEG content and monolayer curing depth. With increasing the monolayer exposure time, the yield stress increases and then decreases, and there is an optimum value. The material has the maximum stress at the monolayer exposure time of 13.5 s when the resin content is 50 %.

The influence of the addition of titanium oxide nanotubes on the properties of 3D printed denture base materials.

In this study, the effects of adding titanium dioxide nanotubes (TiO2) to 3D-printed denture base resin on the mechanical and physical properties of denture bases were examined for the first time. The specimens were digitally created using 3D builder software from Microsoft Corporation through computer-aided design. In accordance with the test specifications for transverse strength, impact strength, hardness, surface roughness, and color stability, specimens were designed and printed with certain dimensions following relevant standards. TiO2 nanotubes (diameter: 15-30 nm and length: 2-3 μm) were added to the 3D-printed denture base resin (DentaBase, Asiga, Australia) at 1.0% and 1.5% by weight. Flexural strength, impact strength (Charpy impact), hardness, surface roughness, and color stability were evaluated, and the collected data were analyzed with ANOVA followed by Tukey's post hoc test (α = 0.05). Field emission scanning electron microscopy (FESEM) and energy dispersive x-ray spectroscopy (EDX) mapping were used to evaluate the dispersion of the nanotubes. Compared with those of the control group (0.0 wt.% TiO2 nanotubes), the average flexural, impact, and hardness values of the 1.0 and 1.5 wt.% TiO2 nanotube reinforcement groups increased significantly. Both nanocomposite groups showed significant color changes compared to that of the pure resin, and there was a considerable reduction in the surface roughness of the nanocomposites compared to that of the control group. Adding TiO2 nanotubes to 3D-printed denture base materials at 1.0 and 1.5 wt.% could enhance the mechanical and physical properties of the material, leading to better clinical performance. In terms of clinical applications, 3D-printed denture base material has been shown to be a viable substitute for traditional heat-cured materials. By combining this with nanotechnology, existing dentures could be significantly enhanced, promoting extended service life and patient satisfaction while addressing the shortcomings of the current standard materials.

Effect of SiC dominated with ZrB2 particles on the ablation and mechanical properties of carbon/novolac‐epoxy (EPN1180) composite at 3000°C

AbstractThis study investigates the mechanical properties and erosion resistance of high temperature–pressure carbon‐epoxy novolac insulation reinforced with ZrB2/SiC particles. For this reason, at first, five samples were fabricated using the hot press, which included resin epoxy novolac EPN1180 base without reinforcement and four samples containing resin with 20:80, 30:70, 40:60, and 50:50 of SiC: ZrB2 particles respectively. After manufacturing of the samples, the mechanical properties were evaluated through bending and tensile testing, followed by erosion resistance properties by the use of oxyacetylene flame erosion tests. Chemical composition and surface morphology analysis of the composites were conducted using energy‐dispersive spectroscopy, scanning electron microscopy, and x‐ray diffraction analysis. Results indicate that the addition of ceramic particles enhances both mechanical properties and erosion resistance of the composite. The pure resin sample exhibited the highest weight loss and thickness reduction, while the sample containing 40% SiC and 60% ZrB2 demonstrated the least weight loss and thickness reduction about 55% and 83% respectively compared to pure sample. Additionally, the sample with 30% SiC and 70% ZrB2 had the lowest backside temperature. Furthermore, the sample with 20% SiC and 80% ZrB2 exhibited the highest mechanical properties, with a tensile strength of 422.5 MPa and flexural strength of 587.11 MPa. Morphological analysis revealed the presence of phases such as SiO2, ZrO2, and ZrSiO4 attributable to the ZrB2/SiC particles, contributing to the enhancement of erosion resistance.Highlights Examines volume ratios of ZrB2/SiC. Discovers the best particle ratio (20%SiC, 80%ZrB2) for mechanical properties. Identifies the best particle ratio (30% SiC, 70% ZrB2) for erosion resistance. Reveals key phases enhancing erosion resistance with advanced analysis methods. Linear and mass ablation rate improved by 83% and 55% (best formation).

Tailored bond characteristics in additively manufactured resin bond grinding wheels: achieving optimal performance, high abrasive concentration, and cost efficiency

AbstractThis research study addresses the issues with additive manufacturing of high abrasive concentration as well as highly affordable resin-bond grinding wheels. High-concentration resin bond grinding wheels are high-demand cutting tools that provide high-efficiency grinding operation for a broad range of ferrous and nonferrous metals. Adding a high concentration of abrasive grains into the blend while using high-temperature acrylic resins as a bond material has encountered some difficulties during digital light processing (DLP), such as insufficient flow of material resulting from the high inherent viscosity of the pure resin and less printability due to their dark color, which become worse by adding a high volume of abrasive grains. An engineered bond material achieved through the mechanical alloying of acrylate photopolymers with tailored properties has been discovered during this research study, taking advantage of reduced price, excellent grinding performance, and high grain concentration. The experimental grinding operations comprising medium and high material removal rates were carried out to prove the supreme properties of the SiC- and diamond-printed grinding wheels toward having high accuracy besides a high-quality finished surface. Mechanical characterization including tensile test and grinding performance examination comprising tool wear, cutting force, surface quality, and surface integrity were conducted on the printed and ground parts. The results showed that integrating 14.6 Wt% of Resin A (with higher thermal resistance and viscosity) into the wheel’s composition could contribute to the fabrication of a high-performance grinding wheel, besides having a reliable, fast, and feasible printing process. Furthermore, On-machine and out-of-machine measurements on the ground surface signified that the composition with the highest Resin B concentration (GW-H) offered up to 2 times higher mechanical properties, 33–50% lower grinding forces, 25–50% improved surface qualities, 2–3 times extended tool life span, and less interval dressing operation compared to the grinding wheel containing the lowest Resin B concentration (GW-L).

Effect of nanosized carbon nanotubes, Titanium Nitride and cubic Boron Nitride powders on mechanical and thermal properties of SLA 3D printed resin composites

AbstractThis study explores the development of nanocomposites by incorporating multi‐walled carbon nanotubes (MWCNT), titanium nitride (TiN), and cubic boron nitride (c‐BN) nano powders into photo‐polymer epoxy resins for use in Stereolithography (SLA) additive manufacturing. Mechanical and thermal properties were systematically investigated to assess their performance. Initially, MWCNT, TiN, and c‐BN nano powders were homogeneously mixed with the resin to ensure uniformity. The resulting mixtures were then processed using SLA technology to evaluate production quality and material performance. The study revealed significant improvements in mechanical and thermal properties compared to pure resin, aligning with previous research outcomes. Specifically, the incorporation of MWCNT led to a notable enhancement in thermal conductivity, showing an increase of 24.21% as the thermal conductivity coefficient increased from 0.19 to 2.36 W/m·k. On the other hand, c‐BN significantly boosted mechanical strength, resulting in a substantial 20.45% increase as the shore D hardness went from 88.53 to 106.64. These findings highlight the promising potential of nanocomposites across various industries including electronics, aerospace, automotive, construction, medical devices, and manufacturing.Highlights Developed nanocomposites with MWCNT, TiN, and c‐BN in SLA resin. c‐BN increased hardness by 20.45%, proving its effectiveness in composites. MWCNT enhanced thermal conductivity by 24.21%, boosting material performance. Pioneering use of TiN and c‐BN in SLA, addressing gaps in existing research. Applications span electronics, aerospace, automotive and medical devices.

Preparation of short carbon fiber reinforced photosensitive resin and composite material properties study

AbstractLight‐curing rapid prototyping (SLA) has become an emerging technology in the manufacturing industry because of its high precision, rapid prototyping, and the ability to mold complex parts. To enhance the mechanical properties and thermal stability of its raw material photosensitive resin (PR), carbon fiber (CF) was surface modified by chemical oxidation and grafting of amino silane (KH550) to obtain KH550‐modified carbon fiber (ACF). Then, ACF was composited with photosensitive resin to obtain modified carbon fiber/photosensitive resin (ACF/PR) composites. The viscosities of ACF/PR composites, including the viscosity, curing shrinkage, mechanical properties, and thermal stability of the ACF/PR composites, were characterized. The results showed that KH550 was successfully grafted onto CF. When the addition of ACF in the composites was 0.6%, the tensile strength, elongation at break, and impact strength of ACF/PR reached 39.48 MPa, 20.32%, and 13.62 kJ/m2, which were 120%, 27.15%, and 154% higher than that of the pure resin; the thermal decomposition temperatures and the maximum thermal decomposition temperatures at 50% mass loss of ACF/PR increased to 457.66°C and 442.44°C at 50% mass loss, which is 3.95% and 3.63% higher than that of the pure resin. Currently, the composites have excellent strength, toughness, and thermal stability. This paper gives a cost‐efficient method for improving the functioning of PR.Highlights Mixed acid oxidation and amino silane modification of CFs. Preparation of modified CF/photosensitive resin composites. Composites with excellent mechanical properties and thermal stability.

A Comparative In Vitro Physicochemical Analysis of Resin Infiltrants Doped With Bioactive Glasses.

Objective This study aimed to investigate the longevity and effectiveness of bioactive glass (BAG)-based dental resin infiltrants. Materials and methods The three types of BAG - 45S5 bioglass (RIS), boron-substituted (RIB), and fluoride-substituted (RIF) - were incorporated with photoinitiated dimethacrylate monomers to create experimental resin infiltrants. ICON® (CN; DMG-America, Ridgefield Park, NJ) and pure resin (PR) were used as control groups in this study. Disc-shaped samples were prepared for the experimental and control groups. The samples were challenged with the pH cycle and immersed in the artificial saliva for 30 days. On Day 0 and Day 30, the pH cycle and artificial saliva immersion, Vicker's microhardness, surface roughness, and surface morphology were investigated. Results The RIF group's disc samples showed the highest Vicker's microhardness values (78.20 ±0.06) on Day 30 of artificial saliva immersion, whereas the CN group's values were the lowest (55.99 ±0.24). Following the pH cycling, the RIF displayed the highest hardness (64.15 ±1.89) whereas the CN group's values were the lowest (33.47 ±1.28). Regarding surface roughness, on Day 30, the RIB resin group exhibited the highest (1.14 ±0.001 µm). In contrast, the CN resin showed the lowest (1.07 ±0.06 µm) values, while immersed in the artificial saliva solution. In the same duration of time, in the pH cycling solution, PR showed the least (0.85 ±0.89 µm), while RIF showed the highest roughness value (0.94 ±0.54 µm). Morphological analysis revealed that following the artificial saliva immersion, the RIB, CN, and PR exhibited smoother surfaces compared to the RIS and RIF groups. However, when immersed in the pH cycling solution, RIB and RIF showed more resistance against acid attack. Conclusions Our results revealed that the experimental resin groups performed much better than the commercial resin infiltrants following artificial saliva and pH cycling challenges.