• Advances in nano research
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• v.15 no.1
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• pp.49-57
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• 2023

As composite materials are used in many applications, the modern world looks forward to significant progress. An overview of the application of composite fiber materials in sports equipment is provided in this article, focusing primarily on the advantages of these materials when applied to sports equipment, as well as an Analysis of the influence of sports equipment of fiber-reinforced composite material on social sports development. The present study investigated surface morphology and physical and mechanical properties of S-glass fiber epoxy composites containing Al₂O₃ nanofillers (for example, 1 wt%, 2 wt%, 3 wt%, 4 wt%). A mechanical stirrer and ultrasonication combined the Al₂O₃ nanofiller with the matrix in varying amounts. A compression molding method was used to produce sheet composites. A first physical observation is well done, which confirms that nanoparticles are deposited on the fiber, and adhesive bonds are formed. Al₂O₃ nanofiller crystalline structure was investigated by X-ray diffraction, and its surface morphology was examined by scanning electron microscope (SEM). In the experimental test, nanofiller content was added at a rate of 1, 2, and 3% by weight, which caused a gradual decrease in void fraction by 2.851, 2.533, and 1.724%, respectively, an increase from 2.7%. The atomic bonding mechanism shows molecular bonding between nanoparticles and fibers. At temperatures between 60 ℃ and 380 ℃, Thermogravimetric Analysis (TGA) analysis shows that NPs deposition improves the thermal properties of the fibers and causes negligible weight reduction (percentage). Thermal stability of the composites was therefore presented up to 380 ℃. The Fourier Transform Infrared Spectrometer (FTIR) spectrum confirms that nanoparticles have been deposited successfully on the fiber.

• Journal of the Korean Wood Science and Technology
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• v.29 no.3
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• pp.47-58
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• 2001

For finding both ways of recycling the wood and plastic wastes and solving the problem of free formaldehyde gas emission through manufacturing wood particle-polypropylene fiber composite board without addition of formaldehyde-based thermosetting resin adhesive, control particleboards and nonwoven web composite boards from wood particle and polypropylene fiber formulation of 50 : 50, 60 : 40, and 70 : 30 were manufactured at density levels of 0.5, 0.6, 0.7, and 0.8 g/$cm^3$, and were tested both in the physical and mechanical properties according to ASTM D 1037-93. In the physical properties, control particleboard had significantly higher moisture content than composite board. In composite board, moisture content decreased with the increase of target density only in the board with higher content of polypropylene fiber and also appeared to increase with the increase of wood particle content at a given target density. Control particleboard showed significantly greater water absorption than composite board and its water absorption decreased with the increase of target density. In composite board, water absorption decreased with the increase of target density at a given formulation but increased with the increase of wood particle content at a given target density. After 2 and 24 hours immersion, control particleboard was significantly higher in thickness swelling than composite board and its thickness swelling increased with the increase of target density. In composite board, thickness swelling did not vary significantly with the target density at a given formulation but its thickness swelling increased as wood particle content increased at a given target density. Static bending MOR and MOE under dry and wet conditions increased with the increase of target density at a given formulation of wood particle and polypropylene fiber. Especially, the MOR and MOE under wet condition were considerably larger in composite board than in control particleboard. In general, composite board showed superior bending strength properties to control particleboard, And the composite board made from wood particle and polypropylene fiber formulation of 50 : 50 at target density of 0.8 g/$cm^3$ exhibited the greatest bending strength properties. Though problems in uniform mixing and strong binding of wood particle with polypropylene fiber are unavoidable due to their extremely different shape and polarity, wood particle-polypropylene fiber composite boards with higher performance, as a potential substitute for the commercial particleboards, could be made just by controlling processing variables.

• Journal of Conservation Science
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• v.26 no.1
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• pp.61-67
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• 2010

After selecting five types of adhesive epoxy resin for metallic cultural assets such as $Araldite^{(R)}$ rapid type, $Devcon^{(R)}$, $Araldite^{(R)}$ SV427+HV427, $CDK^{(R)}$520, $Araldite^{(R)}$ AW106+HV953 which had already been studied, this paper approached more closely the problem of yellowing and the signal of aging with time passing by connecting the problems with the safety of metallic cultural assets. The change of physical properties according to the change of state of epoxy adhesives was investigated through the change of flexural strength and the change of surface hardness by artificially providing the possible environmental change factors such as ultra-violet ray, and acid base, and how the epoxy chemically changes in its ingredients by the environment was analyzed through FT-IR. As a result of the experiment, for the most part of adhesives brought about the physical change of flexural strength, the change of surface hardness, and the chemical change of chemical ingredients as the product of alcohol, which were respectively different according to the time of ultraviolet irradiation, and acid base change. Under most of the conditions, SV427+HV427 and $CDK^{(R)}$520 were fairly stabilized under each condition of weatherability, but it seems that they should be refrained from being applied in case that the area to restore is thin and wide because the degree of flexural strength of themselves is low. Also, it is found that the preservation environment is very important not only for artifacts but also for the preservation of resins sused for preservation treatment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.10
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• pp.339-345
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• 2018

We investigated the curing properties of cured coatings for a multi-focal UV-LED. The coatings are for LEDs that operate at multiple UV wavelengths, unlike conventional single-wavelength UV-LEDs. Using UV-LED light sources with wavelengths of 365, 395, 420, and 450 nm, we analyzed the optical characteristics such as the direction of light flux and light source. We also analyzed the curing characteristics at each UV-LED wavelength to optimize the LED for composite wavelengths. The curing performance state was predicted through computer simulation for when the multiple wavelengths of UV light sources are superimposed, and then actual LEDs were designed and fabricated. To improve the internal high-speed curing, a multi-spot module was fabricated, in which each LED is condensed, and multiple wavelengths are synthesized and condensed at the same position. The adhesive strength, surface hardness, and internal hardness of the curing agent were tested by varying the wavelength combination conditions. The surface hardening and internal hardening were compared and analyzed using a hardness tester and FT-IR analyzer. As a result, the characteristics of the surface and internal hardness were improved by a multi-spot method in which four wavelengths were overlapped in a UV-LED rather than a single wavelength.

• Journal of Conservation Science
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• v.35 no.6
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• pp.701-708
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• 2019

Animal glue is a natural adhesive made from processed skins or bones of animals. It is widely used in wooden crafts, papercrafts, dancheong painting, and pictures. Accurate evaluation of the quality of animal glues during production and use is difficult because there is no formal method for testing the glue's properties during pretreatment and measurement conditions. Thus, in this study, a series of tests were carried out by changing the conditions of swelling, temperature, and concentration of animal glue and gelatin sold on the market. Twelve types of animal glues were evaluated, having a viscosity range of 12.67 cP to 29.43 cP. The results showed that the physical characteristics of the glues were stable when allowed to swell for six h in distilled water(23℃). When 10%(by weight in distilled water) of the animal glue was measured in the reflective mode of a spectrophotometer, the optical characteristics of the glues were stable. Powdered animal glues have a medium brightness and middle-high chroma. Relative to powdered glues, stick animal glues have a low brightness and a medium chroma. Based on the results of this study, it is expected that the data can be assembled into a form so that animal glue workers can use it as a reference for the preparation of evaluation standards for testing the characteristics of animal glues.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.5
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• pp.1741-1746
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• 2010

This study is on development of UV-cured anti-stain coating compounds which have more improved anti-stain function to prevent a surface of PVC tile from stain. To make an anti-stain coating composition, water soluble antistatic agent made from ammonium(IV) salt, antistatic agents for acrylic and polyurethane were used. Their contents varied from 5 to 20wt% against quantities of resin in coating composition. After coating PVC tiles using bar-coating method that can adjust a thickness, we estimated surface properties of coated layer such as anti-stain, electric resistance, adhesive power, thickness of coating, and so on. Results showed that a coating composition added 15wt% of water soluble antistatic agent and coated with No.12 bar-coater had the optimum surface property in electric resistance($3.24{\times}10^9{\Omega}/cm^2$), anti-stain(ink Test, Dust Test) and adhesive power. We could also find electric resistance and anti-stain effect were improved as antistatic agent content increased. However, excessive addition of antistatic agents(over 20wt%) caused the migration.

• Korean Chemical Engineering Research
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• v.55 no.1
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• pp.34-39
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• 2017

In this study, intermolecular crosslinked carboxymethyl cellulose sodium salt (CMC) and porcine Cartilage Acellular Matrix (PCAM) blended hydrogel films for anti-adhesive barriers were prepared by gamma-ray radiation. The effects of the CMC/PCAM concentration and blending ratio on the morphology, gel fraction, gel strength, and degree of swelling were determined. The results indicated that crosslinked CMC/PCAM films show significantly lower the gel-fraction than CMC films. The degree of attachment and proliferation of human vascular endothelial cells on CMC/PCAM films was lower than the CMC films. We show the capacity of the CMC and PCAM to be hydrogel films, and the ability to reduce cell adhesion and proliferation on these films by modification with cell anti-adhesion molecules of PCAM. In conclusion, this study suggests that radiation cross-linked CMC/PCAM hydrogel films endowed with anti-adhesion ligands may allow for improved regulation of cell anti-adhesion behavior for prevent peritoneal adhesions.

• Composites Research
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• v.28 no.4
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• pp.191-196
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• 2015

In this study, the static analysis and experiment were carried out on DCB specimens manufactured with aluminum foam in order to investigate the fracture toughness at the adhesive joint of the structure bonded with adhesive. In case of static analysis, all specimen models were shown to have the maximum reaction force when the forced displacement proceeded as much as 5 mm. The maximum reaction forces became 0.25 kN, 0.28 kN and 0.5 kN respectively in cases of specimen thicknesses of 35 mm, 45 mm and 55 mm. Two specimens in case of static experiment were selected to verify these analysis results. The maximum reaction forces were shown when the forced displacement proceeded as much as 5 to 6 mm. The maximum reaction forces became 0.22 kN and 0.3 kN respectively in cases of specimen thicknesses of 35 mm and 45 mm. By comparing the derived results, it could be shown that there was not much difference between the data of analyses and experiments. Therefore, It is inferred that the study data can be secured with only analysis by no extra experimental procedure. It is thought that the mechanical properties at the structure bonded of DCB with the type of mode III can be analyzed systematically.

• The Journal of Korean Academy of Prosthodontics
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• v.38 no.4
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• pp.427-437
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• 2000

Recently the 2nd generation laboratory composite resins were introduced. Although the mechanical properties of these composite resins have been improved, there were some disadvantages such as discoloration, low abrasion resistance and debonding between metal and resin. The purpose of this study was to evaluate the tensile bond strength between non-pecious dental alloy(verabond) and four veneering reinforced composite resins ; Targis(Ivoclar Co., U.S.A.), Artglass(Kulzer CO., Germany), Sculpture(Jeneric Pentron Co., U.S.A.), and Estonia(Kurary Co., Japan). All test metal specimens were polished with #1,000 SiC paper, and sandblasted with $250{\mu}m$ aluminum oxide. After then. according to manufacturer's instructions metal adhesive primer and veneering resins were applied. All test specimens were divided into two groups. One group was dried in a desiccator at $25^{\circ}C$ for 3 days, the other group was subjected to thermal cycling($2,000{\times}$) in water($5/55^{\circ}C$). Tensile bond strength was measured using Instron Universal Testing machine and the fractured surface was examined under the naked eyes and scanning electron microscope. Within the limitations imposed in this study, the following conclusions can be drawn: 1. In no-thermal cycling groups, there were no significant differences between Estenia and VMK68 but there were significant differences between Targis, Artglass, Sculpture and VMK68(p<0.05). 2. In no-thermal cycling resin groups, the highest tensile bond strength was observed in Estenia and there were significant differences between Estenia and the other resins(p<0.05). 3. Before and after thermal cycling, there were significant differences in tensile bond strength of Targis and Artglass(p<0.05). The tensile bond strength of Artglass was decreased and that of Targis was increased. 4. In no-thermal cycling groups, Artglass showed mixed fracture modes(95%), but after thermal cycling, Artglass showed adhesive fracture modes(75%).

• Journal of Adhesion and Interface
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• v.11 no.2
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• pp.41-49
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• 2010

Furan-containing epoxide monomers (8, 9) were designed and synthesized as carbon-neutral, environment-friendly adhesion material. Bicyclic skeleton were constructed using the Diels-Alder reaction of furan and methyl acrylate, both readily accessible starting material from a biomass via bio-refinery process. After reduction of ester functionality, resulting hydroxyl moieties were coupled to epichlorohydrin to provide the epoxy-functionalized furanic monomers (8, 9). The structure of new furanic monomers was confirmed by $^1H$ and $^{13}C$ NMR spectroscopy. As UV-curable monomers, basic properties such as UV curing time and the extent of UV curing were evaluated by photo DSC. Photo-curing shrinkages were measured by linear variable differential transformer transducer (LVDT) and the effect of molecular structure on shrinkage was considered. In addition, new synthetic compounds showed the shear strength over 3 MPa when they were photo-cured between polycarbonate plates, which indicates these compounds are feasible to use as photo-curable adhesive materials.