Resin Binder Research Articles

Transmission and Reflection Properties of Iron Pyrite-Epoxy Resin Composite for Electromagnetic Applications

This study examines the electromagnetic properties of a composite material composed of iron pyrite (FeS2) and epoxy resin, mixed in a 3:2 weight ratio to create a 10 cm3 cube. The research analyzes transmission and reflection coefficients and band gap parameters to determine its viability as an antenna substrate for electromagnetic wave applications. The composite displays a tunable band gap of 1.3 eV, enabling selective absorption and emission of electromagnetic radiation. The transmission coefficient achieved 90% throughout a frequency range of 1 GHz to 15 GHz, whilst the reflection coefficient was measured at 10%, significantly reducing reflecting losses. The epoxy resin binder was essential for preserving structural integrity and augmenting the dielectric characteristics of the composite, thereby raising transmission efficiency. UV-Vis spectroscopy showed an absorption value of 0.875% at the band gap, indicating efficient interaction with UV energy. The S21 transmission coefficient ranged from −10 dB to −80 dB, with a maximum of −40 dB at 6 GHz, indicating strong energy transfer capability for antenna applications. The S21 values exhibited negligible signal attenuation between 2 GHz and 7 GHz, indicating the material’s exceptional suitability for antenna substrates necessitating dependable transmission. The S11 reflection coefficient varied from −5 dB to −55 dB, with substantial decreases between 4 GHz and 14 GHz, when reflection decreased to −45 dB, signifying little signal reflection at essential frequencies. The results underscore the composite’s appropriateness for applications requiring high transmission efficiency, little reflection, and effective engagement with electromagnetic waves, especially as an antenna substrate. Measurements were performed using a vector network analyzer (VNA) to obtain the S11 and S21 characteristics, underscoring the material’s potential in sophisticated electromagnetic applications.

The Characterization of Natural Resins and a Study of Their Degradation in Interactions with Zinc Oxide Pigment

In the last few years, the role of science in Cultural Heritage has assumed greater significance since diagnostics have become essential for the characterization of artworks. The development of conservation strategies involves growing the study of artworks and the knowledge of the materials used against the degradation plaguing the painted surfaces. This work focuses on the investigation of the degradation processes involving paintings on canvas, in particular delamination and progressive deterioration of the painted surfaces. The main causes of the degradation are attributable to the formation of metal soaps, which originate from the interaction between binders and pigments; as a result, the process leads to the progressive fracturing of the paint film. Using various characterization techniques allowed us to acquire information on the structural and morphological properties of the binder resins and study the binder/pigment interaction during the degradation process to understand the quantity and quality of the acid sites present in the binders and, consequently, the potential reactivity with the cationic part of the pigments. The binders were also analyzed within paint layers in contact with zinc oxide to study the interactions and the possible formation of new species as metal soaps and metal oxalates that can modify the boundary among the painting layers and, consequently, the appearance of the artwork and its artistic value. Modifications after UV and thermal aging processes were observed using Infrared spectroscopy and thermogravimetric analysis. Zinc soap formation was observed after 7 h of a UV aging process and was correlated to the acidity of the resins.

A novel ultra-light bio-based fiberboard from mexican feather grass for thermal and acoustic insulation in green building construction applications

The use of natural fibers as raw materials for insulation fiberboard production is emerging as a strategy to replace wood fibers. This study developed an ultralightweight natural fiber insulation core fiberboard (CFB) with high mechanical strength, hygroscopic resistance, and excellent acoustic and thermal insulation properties. This study examined the production of CFB, which utilizes Mexican feather grass fibers with an epoxy resin binder across a range of densities of 0.18–0.36 g∙cm−3. Furthermore, the impact of incorporating a reinforcing skin layer of woven glass fibers on the core fiberboard's physical, mechanical, acoustic, and thermal properties was evaluated. All the fiberboard samples exhibited excellent thermal conductivity values (0.048–0.057 W/mK), which increased with increasing panel density (0.18–0.36 g∙cm−3). In addition, all of them displayed superior mechanical properties following the ASTM C208 standard. In terms of climatic resistance of the fiberboards, the results displayed excellent water resistance, exhibiting minimal humidity content (<5 %), thickness swelling (<6.5 %), and a hydrophobic surface, as indicated by the high-water contact angle (>121.96 at 30 s). Sound reduction exhibited a frequency-dependent tendency, with denser and sandwich fiberboards showing greater sound reduction of up to 27.9–36.56 dB at 3150 Hz for CFB-0.36 and SFB-0.52, respectively. Following ASTM C208, both core fiberboards and those coated with woven glass fiber skins (sandwich fiberboards, SFB) met the thermomechanical property requirements for regular and structural wall sheathing applications, respectively. These findings highlight the potential of Mexican feather grass as a bio-based alternative to wood, enabling the production of eco-friendly ultralightweight fiberboards with excellent thermomechanical properties suitable for building construction, such as regular and structural wall sheathing applications and ceiling decorations.

Experimental Investigation of Quasi‐Static Compressive Properties of Polymer‐Bonded Explosives (PBX) Based on UV‐Curing 3D Printing

AbstractUltraviolet(UV)‐curing 3D printing in the preparation of explosives has get more attention due to its manufacturing flexibility. To study the effects of binder formulations on compressive properties of PBX for UV‐curing, cast HMX‐based polymer‐bonded explosives (PBX) with 5 groups of binder formulations are prepared by extruded‐based UV curing 3D printer. The test shows that the density of printed explosives exceeds 90% of the theoretical density and quasi‐static compression tests are conducted to analyze the mechanical properties of printed explosives. The results suggest that the elastic modulus and compressive strength of printed explosives with photocurable monomer TMP3EOTA as binder resin have increased by 693.1% and 424%, respectively, compared to those using polyether resin. Moreover, the mechanical properties improve as the content of Isophorone diisocyanate(IPDI) increases from 1 wt. % to 22 wt. %. The addition of aluminum powder decreases the elastic modulus and strength of samples printed by 59.5% and 62%. Meanwhile, the failure modes of printed grains have been also determined. This work provides practical references for future research of PBX on UV‐curing.

DEVELOPMENT AND ASSESSMENT OF PARTICLE REINFORCED ABRASIVE GRINDING DISCS FROM LOCALLY SOURCED MATERIALS

Management of waste materials is a serious concern to researchers and scientists. Waste materials cause health and environmental hazards. Hence, they should be properly managed. The aim of this study is to develop a grinding disc using agricultural wastes (palm kernel shell and snail shell), granite, aluminium oxide, and polyester resin. The particles of snail shell, palm kernel shell, aluminium oxide (abrasive) and granite (friction modifier) were measured in percentages varying between 8 - 29 wt. % and were mixed with 27 wt. % polyester resin (binder), 3 wt. % methyl ethyl ketone peroxide (hardener) and 3 wt. % cobalt naphthalene (accelerator) to produce a grinding disc. The micrograph, hardness, wear rate, and water absorption tests were carried out on the grinding disc samples. The result showed that the composition with the highest palm kernel shell particle content (29 wt. %) had the best values for hardness and wear resistance, making it the most suitable material for grinding discs. The environmentally-friendly palm kernel shell-based discs could be used for soft metals, wood grinding and finishing processes.

Analysis of electrothermal damage in a radome exposed to electromagnetic radiation

Abstract After nearly 9 months of electromagnetic irradiation with a power density of 10 W/cm2, the unit blocks of an A-sandwich radome in the electromagnetic beam scanning area experienced electrothermal damage. Both the inner skin and core layer foam of the A-sandwich unit blocks in that area present different levels of damage. The inner skin is wrinkled and cracked, and the core layer foam is locally charred, carbonized, and ablated. The temperature images recorded through the infrared thermal beam method show that the temperature distribution of the unit blocks in the beam irradiation area is abnormal and strongly related to the discontinuous structure distribution of the core foam and resin. The non-uniformity of core material is the main cause of the electrothermal damage to unit blocks. By process improvements, the shaping of the polyurethane foam core layer is changed from cutting, resin bonding, and splicing to one-step foaming without resin binder, and the continuity of the core layer material is ensured. The usage results of unit blocks made by the new process show that the temperature field distribution is uniform, with a maximum temperature of only 31.3°C, which is 71.62% lower than the maximum temperature of 110.3°C in the damaged block.

Effect of Si3N4 on the in-situ synthetized non-oxide reinforcements in Al-Al2O3 composites under N2 atmosphere

Al-Al2O3 composite is widely used in high-temperature industry due to its excellent properties obtained through in-situ synthesis of non-oxide reinforcing phases. The effect of nitrogen source on the non-oxide reinforcing phases synthesized in-situ in the Al-Al2O3 composites at 1500 °C was investigated. The results show that when N2-gas is the sole nitrogen source, Al4O4C is the major reinforcing phase formed in the composite due to insufficient nitrogen amount provided. Through the construction of an Al@AlN core-shell structure and spontaneous nitrogen introduction by solid Si3N4 and N2-gas, higher amount of AlN mesophase is generated, and the complete transformation of Al to (Al2OC)1-x(AlN)x solid solution is successfully achieved. However, when Si3N4 content is excessive (i.e. Si/C mole ratio ≥ 1, where Si comes from solid nitrogen source Si3N4, C comes from phenolic resin binder), the stability of (Al2OC)1-x(AlN)x solid solution decreases, and more stable AlN-SiC solid solutions and SiAl4O2N4 are generated as reinforcing phases in the composite. This work provides meaningful information for the phase control of Al-Al2O3 composite at high temperature application.

Assessment of chemical degradation of epoxy resin binder used in the service of the Qin terracotta warriors

Since the Qin terracotta warriors were unearthed, polyamide 650 cross-linked E-44 epoxy resin binder has been employed to bond and restore them. In this paper, the chemical aging of the binders service in indoor natural environment during the past 30 years in the terracotta warriors was studied by means of infrared spectroscopy, X-ray photoelectron spectroscopy and thermogravimetric analysis. The results indicated that the binders did not emerge the characteristic peak of carbonyl stretching vibration at 1700 cm−1 in the IR spectra of all determined binders, and their thermal decomposition curves did not emerge any abnormal changes, and the thermal decomposition mainly occurred above 300 °C. There are evident ceramic grains attached to the surface of the binders being peeled off for sampling. These results that the binders service in the Qin terracotta warriors did not exhibit an observable chemical aging and still has strong adhesion. Generally, discrepancies were observed between natural aging and accelerated artificial aging due to the ineffectiveness of the latter to reproduce the effects of complex weather conditions. Compared to artificially accelerated aging, the evaluation results in a long-term natural aging of the binder which is used for restoration of the life-size Qin terracotta warriors, providing in the present investigation, are more reliable in terms of predicting the safety of restored terracotta warriors.

Multiaxial filament winding of biopolymer microfibers with a collagen resin binder for orthobiologic medical device biomanufacturing

Multiaxial filament winding is an additive manufacturing technique used extensively in large industrial and military manufacturing yet unexplored for biomedical uses. This study adapts filament winding to biomanufacture scalable, strong, three-dimensional microfiber (3DMF) medical device implants for potential orthopedic applications. Polylactide microfiber filaments were wound through a collagen ‘resin’ bath to create organized, stable orthobiologic implants, which are sized for common ligament (e.g. anterior cruciate ligament) and tendon (e.g. rotator cuff) injuries and can be manufactured at industrial scale using a small footprint, economical, high-output benchtop system. Ethylene oxide or electron beam sterilized 3DMF samples were analyzed by scanning electron microscopy (SEM), underwent ASTM1635-based degradation testing, tensile testing, ISO 10993-based cytocompatibility, and biocompatibility testing, quantified for human platelet-rich plasma (PRP) absorption kinetics, and examined for adhesion of bioceramics and lyophilized collagen after coating. 3DMF implants had consistent fiber size and high alignment by SEM. Negligible mass and strength loss were noted over 4 months in culture. 3DMF implants initially exceeded 1000 N hydrated tensile strength and retained over 70% strength through 4 months in culture, significantly stronger than conventionally produced implants made by fused fiber deposition 3D printing. 3DMF implants absorbed over 3x their weight in PRP within 5 min, were cytocompatible and biocompatible in vivo in rabbits, and could readily bind tricalcium phosphate and calcium carbonate coatings discretely on implant ends for further orthobiologic material functionalization. The additive manufacturing process further enabled engineering implants with suture-shuttling passages for facile arthroscopic surgical delivery. This accessible, facile, economical, and rapid microfiber manufacturing platform presents a new method to engineer high-strength, flexible, low-cost, bio-based implants for orthopedic and extended medical device applications.

Uniaxial compression behavior of glass fabric/epoxy composites sprayed with nano titanium dioxide

ABSTRACT In this study, we have tried to study the compression behaviour of composites by a different technique of spraying nano – TiO2 on glass fibre fabrics with vinyl resin as binder and epoxy resin as matrix. It was found that the air spraying method was effective in loading the nanoparticles onto the fabrics and improving their wetting properties with the resins. The experimental results showed that the compressive strength of the modified specimens was lower than that of the untreated ones, while their compressive strength was increased. On this basis, the fracture process of the material was observed using microscopy, and electron microscopy observations revealed that the degree of interfacial bonding between the material and the substrate was improved, while the bond strength demonstrated the strong toughening effect of nano – TiO2 on the substrate. Electron microscopy tests also showed that the composites modified by nano- TiO2 showed significant improvement in matrix fracture, fibre breakage and delamination. This study provides a theoretical basis for the study of the mechanical properties of composite materials used as supports under uniaxial compression.

Effect of Hot-Pressing Temperature on the Properties of Eco-Friendly Fiberboard Panels Bonded with Hydrolysis Lignin and Phenol-Formaldehyde Resin.

Lignin is the natural binder in wood and lignocellulosic plants and is regarded as the main natural and renewable source of phenolic compounds. Its incorporation in the composition of fiberboards will enhance both the environmental performance of the panels and the complex use of natural resources. In recent years, the increased valorization of hydrolysis lignin in value-added applications, including adhesives for bonding fiberboard panels, has gained significant research interest. Markedly, a major drawback is the retention of lignin in the pulp until the hot-pressing process. This problem could be overcome by using a small content of phenol-formaldehyde (PF) resin in the adhesive mixture as an auxiliary binder. The aim of this research work was to investigate and evaluate the effect of the hot-pressing temperature, varied from 150 °C to 200 °C, in a modified hot-press cycle on the main physical and mechanical properties of fiberboard panels bonded with unmodified technical hydrolysis lignin (THL) as the main binder and PF resin as an auxiliary one. It was found that panels with very good mechanical properties can be fabricated even at a hot-pressing temperature of 160 °C, while to provide the panels with satisfactory waterproof properties, it is necessary to have a hot-pressing temperature of at least 190 °C.

Utilization of Bamboo Roots as Reinforcing Composite Materials for Light Vehicle Dashboards

Bamboo roots are residual material from the utilization of bamboo trees’ waste. Bamboo roots utilize in engineering by making new materials in the form of composites. Bamboo roots are easy to get, and getting bamboo root fiber is relatively easy compared to getting bamboo stem fiber. Bamboo root fibers are used as reinforcement in composites with resin binders and catalysts as hardeners. The composite made by mixing the composition consists of 10% bamboo root fiber, 89% resin, and 1% catalyst from the weight of the specimen. This composition uses three variations of fiber direction; straight, random, and woven fiber—each variation tests tensile strength, impact, and bending strength. Those three test results show that the highest values come from the woven fiber, which are 21.04 MPa from the tensile strength, 0.0693 J/mm2 from the impact value, and 34.789 MPa from the bending strength value. The test result found that applying bamboo roots composite material suits dashboard material for light vehicles (cars and motorcycles). This test result meets the standard material for dashboard vehicles based on plastic material data ABS (Acrylonitrile butadiene styrene). This research on natural fiber composite material is novel and valuable as a waste utilization solution for engineering materials.

Influence of SiO2–ZnO mixed soft abrasive on tribological behavior and polishing performance of sapphire wafer

The use of reactive soft abrasives, capable of undergoing solid-state reactions with sapphire, is a promising approach for low-damage and low-contamination machining of sapphire wafers. This study calculates the Gibbs free energy change of these chemical reactions based on thermodynamic principles. SiO2–ZnO mixed soft abrasives were selected for the polishing of sapphire wafers. Friction and wear experiments were conducted to explore the tribological behavior of sapphire wafers with various mixed abrasives, leading to the optimization of the abrasive composition. The results show that mixed abrasives significantly enhance the material removal rate (MRR) of sapphire wafers. As the proportion of SiO2 in the mixture increases, the MRR correspondingly rises. Specifically, an SiO2–to–ZnO ratio of 2:1 in the mixed abrasives results in a 91.68% increase in MRR compared to using SiO2 abrasives alone. Based on these findings, five grinding discs with different abrasive ratios were prepared using a resin binder for mechanical–chemical polishing experiments on sapphire wafers. The polishing results corroborate those of the friction and wear experiments, confirming that an increased SiO2 content in the mixed abrasive discs leads to higher MRR. With a 2:1 ratio of SiO2 to ZnO in the mixed abrasive disc, the MRR is enhanced by 342.9% compared to discs with only SiO2 abrasives, while reducing the surface roughness to 3.21 nm. In the SiO2–ZnO mixed abrasives, the inclusion of ZnO enhances chemical reactions during polishing. Aided by the mechanical removal efficacy of SiO2, this approach significantly increases MRR while maintaining superior polishing quality.

Mats Made from Recycled Tyre Rubber and Polyurethane for Improving Growth Performance in Buffalo Farms

This study focuses on anti-trauma mats designed for buffaloes’ comfort, using as raw materials rubber powder from end-of-life tyres (ELTs) and an isocyanate-based polyurethane resin binder. The first part of the study focused on mat formulation. Whilst it was possible to select a unique combination of raw materials and design features, it was necessary to investigate the relationship between three critical parameters affecting mat consistency and therefore buffalo comfort: binder quantity, mat thickness, and desired final mat density (bulk). In order to quantitatively assess the variation in hardness, various combinations were investigated within well-defined ranges based on the relevant literature. The results obtained from nine selected combinations indicate that increases in the three critical parameters do not induce a real phase transition in the final product consistency, although the hardness suggests an increasing trend. The mats consistently exhibited a moderately soft/hard consistency, offering environmental benefits in terms of increased rubber usage and potentially reduced chemical binder, depending on the desired thickness. The selected mixture showed excellent resistance to heavy chemical loads, suggesting reliability for frequent cleaning operations. The second part of the study involved field trials of the mats with calves. This involved monitoring their weight gain and appetite levels over a 90-day period. The results showed excellent growth performance compared to uncoated grids (i.e., weight gain was approximately 20% higher at the end of the observation period); this was similar to that achieved with the use of straw bedding. However, compared to straw bedding, the mats (i) exhibit long-term durability, with no signs of wear from washing or trampling over the months of the trial, (ii) allow for quick and efficient cleaning, and (iii) enable companies to save on labour, material (straw), and waste disposal costs, while maintaining (or even improving) the same welfare levels associated with the use of straw.

STUDY ON MECHANICAL PROPERTIES OF DEVELOPED ECO-FRIENDLY BRAKE PADS USING GRAY RELATIONAL ANALYSIS IN BOX BEHNKEN DESIGN OF EXPERIMENT

Over the years, asbestos has been a leading material for developing automobile brake pads. However, due to its hazardous nature to human health, many researchers have found that organic materials possess the potential for replacement. The organic materials used in this research were the hybrid of coconut fruit fibre CFF and oyster sea shell OSS. These materials were gathered from the river bank, dried, crushed, washed, ground, sieved, and moulded with different additives: CuO (abrasive), graphite (friction modifier or solid Lubricant), epoxy resin (binder), hardener (catalyst) by Box Behnken design BBD of L27 experiment. Therefore, an experimental test on mechanical properties was performed to check the developed brake pad's characterization. Then, grey relational analysis was used to analyze grey relational grade GRG to convert a multiple response process optimization problem into a single response optimization using maximization of maximum GRG. The optimum parameter values producing the highest value of grey relational grade were chosen as rank one, pertained to the factors setup for experiment number S3232 having moulding pressure of 11.25MPa, moulding temperature of 180oC, and heat treatment time of 180min. The optimized response values obtained from the experiment sample S3232 give the highest values on all the responses, i.e., density of 3.483g/cm3, hardness of 52.91BHN, compressive strength of 2.78MPa, ultimate tensile strength of 3.92MPa, impact energy of 17.87N, cold water absorption of 0.2863%, hot water absorption of 0.4785%, and oil absorption of 0.4402%. After that, the optimized brake pad sample (S3232) was applied to the automobile and was suitable for braking owing to its high mechanical properties.

High strength and high toughness Csf/SiC composites prepared by laser powder bed fusion/ reactive melt infiltration with the impregnation of boron-and silicone-containing phenolic resin

Laser powder bed fusion (LPBF) has emerged as an effective method for preparing complex structured silicon carbide (SiC) ceramics. However, the SiC components demonstrate low strength and high brittleness, which remain major challenges limiting its application. To overcome this limitation, short carbon fiber reinforced silicon carbide (Csf/SiC) composites are prepared by combining LPBF and phenolic resin binder impregnation (PRBI)-reactive melt infiltration (RMI), in which high char yield boron-and silicone-containing phenolic resin (BSiPF) impregnation is used to adjust the carbon density of green bodies and to reduce the pore size of green bodies. By optimizing the impregnation process, the carbon density can be brought close to the theoretical optimal value of 0.84 g/cm3, and the reduction of the pore size is conducive to the improvement of the reaction rate at the early stage of the reaction, which enhance the SiC phase content of Csf/SiC composites obtained by RMI. Meanwhile, the application of BSiPF results in a protective pyrolytic carbon (PyC) coating on the surface of Csf, which can reduce the erosion of Csf by molten Si during the RMI process, thus improving the fracture toughness of Csf/SiC composites. The final Csf/SiC composites exhibit the enhanced bulk density, bending strength and fracture toughness, reaching 2.90 ± 0.01 g/cm3, 257 ± 20 MPa, 3.52 ± 0.15 MPa m1/2, respectively. This study provides a new strategy for effective impregnation technique for the additive manufacturing (AM) of high strength and high toughness SiC composites.

Effect of Surface Hydrophilized Plastic Waste Aggregates Made by Mixing Various Kinds of Plastic on Mechanical Properties of Mortar.

The surface hydrophilization of mixed plastic waste aggregates (MPAs) was conducted to improve the bond between an MPA and the surrounding cement matrix using two types of coating agents: a silicone amine resin and acrylic binders. The coating agents formed a physical bond with the MPAs, and the results of contact angle measurement also revealed that the surface of MPAs was hydrophilic. The workability of a mortar mix increased by up to 1.47 times with the surface hydrophilization of MPAs. Meanwhile, the compressive and flexural strengths of mortar mixes decreased by 29~43% and 72~86%, respectively, at 28 days with the surface hydrophilization of MPAs. Namely, the surface hydrophilization of MPAs was successively conducted, and the workability of mortar mixes was improved accordingly, but the compressive and flexural strengths of mortar mixes decreased as the physical bond was partially separated from not only the MPA but also the surrounding cement matrix and the surface friction was decreased.

Key Materials in Solder Mask Ink for Printed Circuit Board

AbstractSolder mask ink (SMI) layer can avoid the short circuit between electronic component and land for the fabrication of printed circuit board (PCB). More importantly, the layer not only protects the board from the corrosion of moisture, mildew, or salt spray but also reduces the contamination of weld, and increases the degree of insulation by forming stable three‐dimensional net structure. Therefore, the SMI plays a decisive role for the service life of PCB. This review mainly summarizes three types of SMI including epoxy resin ink, acrylic acid resin ink, and phenolic resin ink for PCB. The focus is the effect of the changes of key materials, such as the design of the binder resin, the selection of the curable agent, and the variation of the colorant and initiator on the performances of epoxy resin SMI layer. Then other types of ink such as acrylic acid resin ink and phenolic resin ink have been discussed, especially about how the change of the binder resin influences the SMI film properties. At last, the development trend of the SMI is proposed. The review has significant meaning for the development and improvement of the SMI and the investigation is important for the application and exploitability of the high‐quality PCBs.

Preparation of Transparent Conductive Films Using Carbon Nanotubes

Carbon nanotubes (CNTs), since the discovery by Iijima, have attracted tremendous interests in scientific research mainly due to their exceptional structure and physical properties. The high aspect ratio, light weight, extraordinary stiffness, and strength make CNTs a potentially very functional material to be used in polymer nanocomposites application. Carbon nanotubes are single or multilayered coaxial tubes of six-membered ring networks composed of carbon. It is an allotrope of carbon and is sometimes classified as a type of fullerene. Carbon nanotubes are expected to be applied to materials that normally do not conduct heat or electricity, such as resin, rubber, ink, and paint. In addition, it is expected to be applied to the electronics field because of its conductivity and thermal conductivity even in small quantities and high strength when made into long lengths. One of the problems of CNTs is the tendency of CNTs to aggregate with each other due to intermolecular interactions. In the aggregated state, CNTs cannot exhibit their inherently useful characteristics, and therefore, a technology to disperse CNTs at the nano-level is required. Currently, two major methods are being considered for dispersing CNTs: The first is dispersion by chemical modification. By introducing carboxylic acid into strong acid treated CNTs and introducing hydrophilic or hydrophobic substituents here, solubilization in water or organic solvents is possible. However, there is a problem that this destroys the structure of CNTs and thus greatly impairs their original properties.The other method is to physically disperse CNTs. This is a very simple method that uses ultrasonic irradiation to loosen bundled CNTs, but the dispersion is only temporary, and re-agglomeration occurs quickly. Problems have also been reported, such as excessive ultrasonic irradiation destroying the structure of the CNTs. We have succeeded in producing CNTs nano dispersion gels by adding an aromatic compound to agglomerated CNTs and applying agitation and ultrasonic irradiation. The following describes the process of preparing CNTs dispersion gels. After agglomerated CNTs are temporarily dispersed by ultrasonic irradiation, an aromatic compound (dispersant) is added and mixed and agitated. The dispersed CNTs and the aromatic compound are combined by π-π interaction, and the aromatic compound is adsorbed on the CNTs surface. When CNTs molecules adsorbed with aromatic compounds approach each other, the aromatic compounds on the surface form π-π interactions. At this point, the CNTs are in a gel-like state. Since this dispersion gel does not chemically modify the CNTs, it can be prepared without destroying the structure of the CNTs. The CNTs gel proved to be free from aggregation even after the dispersant component was removed, and the network structure was maintained. In addition, this dispersion gel shows high electrical conductivity because the CNTs are dispersed three-dimensionally and the CNTs form three-dimensional conductive paths in the gel.Next, we introduce the preparation of CNT composite resin. CNT composite resin is prepared by adding binder resin to the carbon nanotube dispersion gel prepared earlier, mixing, and stirring, and ultrasonic irradiation. A transparent conductive film is created by forming the prepared CNT composite resin on a glass slide. In recent years, transparent conductive films have been in high demand due to the development of electronics products, and the use of CNTs as the main material is expected to significantly reduce the cost of development, as they are less expensive than Metallic materials such as indium tin oxide and can be stably supplied. The challenge of this research is that the amount of black CNTs added, which imparts conductivity, significantly affects the transparency of the transparent conductive film. Therefore, it is necessary to select aromatic compounds and resin materials that achieve both high conductivity and transparency with low amounts of added CNTs from a molecular chemistry perspective. In our previous research, we focused on the chemical bonding between resin materials and CNTs for the first time and attempted to improve electrical conductivity by using hydrogen bonding for CNTs. In addition, by combining polycarbonate, which exhibits high transparency and impact resistance, with CNT dispersion gel, we attempted to fabricate a transparent conductive film with high durability. As a result, we succeeded in developing a transparent conductive film material with performance applicable to touch panels.In this study, CNTs dispersion gels prepared with aromatic compounds were evaluated using absorbance measurements and Raman spectroscopy. The Raman spectra measurements allowed us to quantitatively evaluate the interaction between SWCNTs and aromatic compounds. The possibility of charge-transfer complex formation was also suggested by the results of absorbance measurements. Figure 1

Synthesis and characterization of alkyd resins from rubber seed/soybean oil blends

The polymerization and properties of environmentally friendly resin binders applicable in the surface-coating industry were studied. Rubber seed oil (RSO) and RSO blended with 10% and 20% soybean oil (SBO)-based alkyd resins were synthesized by alcoholysis- polyesterification of the oil with glycerol and phthalic anhydride. Physicochemical properties (such as colour, specific gravity, acid value, saponification value, iodine value, and drying schedule) of the alkyd resins were determined to establish the possible industrial potential of the resins. The saponification value and iodine value ranged from 250.19 mgKOH/g to 279.55 mgKOH/g and 29.58 gI2/100g to 33.77 gI2/100g respectively. The drying schedule and chemical resistance of the blended alkyd resins to water, salts, acids, and alkalis were also studied. The blended resins were found to be resistant to water, salt, and acid media, except for alkali media. The colour properties were enhanced as the percentage of the blend increased. FT-IR spectroscopic study of the oil and alkyd resin samples further corroborates our findings. Therefore, the potential of rubber seed oil blended with soybean oil to produce light-coloured alkyd resins could be exploited as raw materials for the Nigerian surface coating industry.