• Composites Research
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• v.24 no.1
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• pp.31-36
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• 2011

Adhesive shear strengths of the established adhesives and the alternative adhesives were evaluated and their chemical structures were analyzed in order to investigate the possibility of replacing the established adhesives with the alternative adhesives applicable to the seeker for the guided missiles. Two types of the adhesives such as the structural adhesives and the sealant adhesives were considered. Those adhesives were exposed to the combined environmental factors consisting of temperature, moisture and ultraviolet over 1000 hours. Adhesive shear test was conducted to evaluate adhesive shear strengths and ATR FT-IR was utilized to investigate chemical structures. According to the results, the adhesive shear strengths of the alternative adhesives revealed higher than those of the established adhesives. Also the alternative adhesives were more stable to the combined environmental condition than the established adhesives. Therefore, it is found that the established adhesives were able to be replaced by the alternative adhesives.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.443-446
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• 2009

In this study, a series of degradation test for structural adhesives was performed to investigate the possibility of replacement of the alternative adhesives to the conventional adhesives. Four types of the adhesives were exposed to combined environmental conditions over 1000 hours at an accelerated aging tester, which can simulate natural weather conditions such temperature, moisture and ultraviolet. Mechanical and chemical properties of the adhesives were evaluated through material testing system and FT/IR spectrometer. According to the results, the conventional adhesives can be replaced by the alternative adhesives because the alternative adhesives were more stable to environmental conditions rather than the conventional adhesives.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2002.09a
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• pp.97-120
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• 2002

• Journal of the Korean Wood Science and Technology
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• v.39 no.5
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• pp.451-458
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• 2011

Adhesives derived from renewable resources allow wood panel producers to make lower cost alternatives to formaldehyde-based adhesive resins. Among them, adhesive components extracted from industrial by-products or wastes are the most important research fields in the efficient utilization of waste and cost reduction. In our study, the rapeseed flour, which is a by product from the production of biodiesel extracted from rapeseed, was introduced to develop alternative adhesives for the production of wood flooring. The rapeseed flour was hydrolyzed with 1% sodium hydroxide solution and PF prepolymers were prepared with 3-molar ratios, 1.8, 2.1 and 2.4. The linear fracture mechanics was introduced to evaluate the glue bond quality in wood flooring composed of fancy-veneered and plywood, and the formaldehyde emission and adhesive penetration were also investigated. The formaldehyde emissions of wood flooring met the requirement of the standard of $SE_0$ specified in the KS standard. The rapeseed flour adhesive penetrated sufficiently into the vessel elements and lumens in fancy veneer and plywood and gave strong bond quality to the wood flooring. The fracture mechanics was introduced to evaluate the adhesive joint between fancy veneer and plywood. The critical stress intensity factor ($K_{IC}$) of boliva overlayed wood flooring was increased with increasing molar ratio and this was the same tendency in oak overlayed wood flooring. From the results, the formulated adhesives were efficiently used to bond fancy veneer onto the plywood to make wood flooring and showed a potential to be used as a component of environmentally friendly adhesive resin systems for production of flooring.

• Journal of Adhesion and Interface
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• v.21 no.4
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• pp.156-161
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• 2020

Waterborne pressure sensitive adhesives (PSA) has been received much attentions from both academia and industries as an environmental friendly-technology because it can significantly reduce use of hazardous organic volatile solvents. However, in the process of the mass production of waterborne PSAs, hazardous phenol type amphiphilic compounds have essentially been used as surfactants for the emulsion polymerization. For the reason, tremendous research efforts have been made to develop environment-friendly organic surfactant which can replace the phenol type surfactants. In this study, we verify the potential of a new class of surfactants based on the styrenated phenol derivatives as an alternative to the phenol type surfactants.

• Restorative Dentistry and Endodontics
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• v.44 no.3
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• pp.23.1-23.9
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• 2019

Objectives: The aim of this study was to investigate the microshear bond strength (${\mu}SBS$) of different universal adhesive systems applied to hybrid computer-aided design/computer-aided manufacturing (CAD-CAM) restorative materials repaired with a composite resin. Materials and Methods: Four types of CAD-CAM hybrid block materials-Lava Ultimate (LA), Vita Enamic (VE), CeraSmart (CS), and Shofu Block HC (SH)-were used in this study, in combination with the following four adhesive protocols: 1) control: porcelain primer + total etch adhesive (CO), 2) Single Bond Universal (SB), 3) All Bond Universal (AB), and 4) Clearfil Universal Bond (CU). The ${\mu}SBS$ of the composite resin (Clearfil Majesty Esthetic) was measured and the data were analyzed using two-way analysis of variance and the Tukey test, with the level of significance set at p < 0.05. Results: The CAD-CAM block type and block-adhesive combination had significant effects on the bond strength values (p < 0.05). Significant differences were found between the following pairs of groups: VE/CO and VE/AB, CS/CO and CS/AB, VE/CU and CS/CU, and VE/AB and CS/AB (p < 0.05). Conclusions: The ${\mu}SBS$ values were affected by hybrid block type. All tested universal adhesive treatments can be used as an alternative to the control treatment for repair, except the AB system on VE blocks (the VE/AB group). The ${\mu}SBS$ values showed variation across different adhesive treatments on different hybrid CAD-CAM block types.

• Journal of Mushroom
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• v.21 no.3
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• pp.83-87
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• 2023

The importance of biocomposites has increased owing to the changes in global consumption trends and rapid climate change. Technologies using mushroom mycelium cultivation, and molding methods for mycelial application have gained attention as potential strategies for producing eco-friendly composites. Currently, mushroom mycelia are used as raw materials for food and cosmetics; however, research on their utilization as biocomposite materials is limited. Therefore, the potential for the development of mushroom mycelium-related products and technologies is high. This review analyzes the domestic and international patent application trends related to the technologies for composite (packaging, insulation, adhesives, and leather) and food (substitute for meat) materials using mushroom mycelium, as an eco-friendly biocomposite material, to provide objective patent information that can further research and development (R&D) in this field.

• Journal of the Korean Wood Science and Technology
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• v.39 no.3
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• pp.221-229
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• 2011

Due to the increase of oil price and the environmental issue such as the emission of volatile organic compounds, the necessity for developing alternative resins of petroleum-based adhesive resins, which have extensively been used for the manufacture of wood-based products, has been speculation since the early 1990. In our study, rapeseed flour (RSF), which is the by-product of bio-diesel produced from rapeseed, were hydrolyzed by enzymes. As a crosslinking agents of the RSF hydrolyzates, phenol-formaldehyde prepolymers (PF) were prepared. The RSF hydrolyzates and PF were mixed to complete the formulation of RSF-based adhesive resins, and the resins were applied to make the laminated veneer lumber (LVL). The physical and mechanical properties of the LVL were measured to examine whether RSF can be used as raw materials of adhesive resins for the fabrication of LVL or not. The average moisture content and soaking delamination rate of the LVL bonded with RSF-based adhesive resins exceeded the minimum requirement of KS standard. Moreover, thermal analysis of the RSF-based resins showed similar tendencies except for the RSF-based adhesive resins formulated with pectinase-hydrolyzed RSF. The bending strengths of the LVL were higher than that of the LVL made with commercial PF resins. These results showed the potential of RSF as a raw material of alternative adhesives for the production of LVL. Further works on the optimal conditions of RSF hydrolysis and spreading characteristics for RSF-based adhesive resins is required to improve the adhesive performance of RSF-based resins.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2001.07a
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• pp.95-99
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• 2001

Cu is considered as a promising alternative interconnection material to Al-based interconnection materials in Si-based integrated circuits due to its low resistivity and superior resistance to the electromigration. New humping and UBM material systems for solder flip chip interconnection of Cu pads were investigated using electroless-plated copper (E-Cu) and electroless-plated nickel (E-Ni) plating methods as low cost alternatives. Optimally designed E-Ni/E-Cu UBM bilayer material system can be used not only as UBMs for solder bumps but also as bump itself. Electroless-plated E-Ni/E-Cu bumps assembled using anisotropic conductive adhesives on an organic substrate is successfully demonstrated and characterized in this study

• Journal of the Korean Society for Precision Engineering
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• v.22 no.9 s.174
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• pp.34-40
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• 2005

Laser welding of thermoplastics is a new jointing technique with a host of advantages. It is not only another extremely useful welding method but also a cost-effective alternative to traditional techniques involving screws or adhesives. Transmission laser-welding of thermoplastics such as polycarbonate(PC), polypropylene(PP), polyvinyl chloride(PVC), low density polyethylene(LDPE) and acrylic using a high power diode laser has been studied experimentally. The optical transmission of each plastic has been measured at laser wavelength of 808nm. The weld process has been characterized by the specific energy and weld time required for each plastic. The characteristics of laser welding between same plastics have also been analyzed.