• Journal of Adhesion and Interface
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• v.21 no.1
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• pp.6-13
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• 2020

The objective of the current study is to characterize the long-term stability and efficacy of a structural adhesive assembly under static load. An apparatus was designed to be used in the Instron tensile test machine that would allow for real time modeling of the failure characteristics of an assembly utilizing a moisture- cure adhesive which was bonded to concrete. A regression model was developed that followed a linear - natural log function which was used to predict the expected life of the assembly. Evaluations at different curing times confirmed the structure was more robust with longer cure durations prior to loading. Finally, the results show that under the conditions the assembly was tested, there was only a small amount of inelastic creep and the regression models demonstrated the potential for a stable structure lasting several decades.

• Journal of the Korean Wood Science and Technology
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• v.33 no.5 s.133
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• pp.66-75
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• 2005

Soybean-based adhesives have recently been reconsidered as alternatives to petroleum-based adhesives due to the uncertainty of availability of petrochemical products and the increased demand for wood adhesives. This study was conducted to investigate the adhesive properties of alkaline phenolic soy (APS) resin for hybrid poplar flakeboard. The APS resin was formulated by crosslinking an alkaline soy flour hydrolyzate with lab-prepared PF resin in the soy hydrolyzate to PF resin weight ratios of 70/30, 60/40, and 50/50. The APS resins were used to fabricate homogeneous hybrid poplar flakeboards with different resin solid levels (5%, 7%, and 9%), press temperatures (175 and $200^{\circ}C$), and press times of 8 and 10 minutes. The IB, wet MOR, and dimensional stability properties of board improved with increasing press time, press temperature, and PF level in APS resins. Increasing press time can be used to offset poor IB strength associated with a 9% resin solid level and the excessive moisture content in the mat. The following conditions were concluded to meet the requirements of the CSA standard for exterior-grade flakeboard: a 50% PF level, a 5% resin content, a $200^{\circ}C$ press temperature, and an 8 minute press time.

• Composites Research
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• v.24 no.3
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• pp.39-45
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• 2011

Adhesive joints are widely used for structural joining applications in various fields and environmental conditions. Polyurethane (PU) and Epoxy adhesives are now being used for liquefied natural gas (LNG) carriers at cryogenic temperatures. This paper presents a comprehensive evaluation of epoxy and PU adhesive bonds between Triplex sheets at normal and cryogenic temperatures. The most significant result of this study is that for all adhesives tested, there is a significant decrease in peel strength at cryogenic temperatures. However, the reasons for the decrease in peel strength for epoxy and PU adhesives differ. Consequently, PU adhesives can be considered better suited for use in applications requiring high bonding performance at cryogenic conditions, such as in LNG carriers.

• 보존과학연구
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• s.29
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• pp.255-278
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• 2008

Considering the physical quality of the wall body in this study we tried to select a replenishing that is proper for filling the cracked part of the painting wall layer and apply the natural adhesives that have traditionally been used, investigating whether it is possible to substitute those for the chemical adhesive which is used at present time. The result of this study showed the red algae adhesive was, in a weathering environment, as safe as the synthetic resin originated from the polyvinyl acetate which is used generally on the present spot, and it was concluded that although the starch adhesive displayed its superiority in enhancing the strength of the earth mortar and its work disposition, it seemed proper for it to be used as a filling adhesive for the first or midterm layer because it showed a surface hardening phenomenon. And also the glue and fish glue were judged they were not qualified as a filling adhesive due to mold occurring in a environment of high moisture that is a biological problem, showing at same time a weak physical feature in a weathering environment. Therefore it would be possible to use the red algae adhesive or starch one substituting them for the original one sold on the present market, if among natural adhesives the weak points of the them were to be corrected.

• Journal of the Korean Wood Science and Technology
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• v.44 no.6
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• pp.872-879
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• 2016

Demand of natural interior finishing material has been widely sprayed in nowadays because many weak people as children, pregnant women, and elder people are being struggled with sick house syndrome due to volatile organic compounds such as formaldehyde, toluene, benzene, etc. Our research group developed a no-added formaldehyde adhesive for wood-based panels from mainly rice powder and some additives in the previous study for abating sick house syndrome. Since the rice powder adhesive provides a good source of nutrients with microorganisms, it was suspected a susceptibility of the rice powder adhesive to fungal and sapstain attack. We evaluated anti-sapstain activity of the rice powder adhesives modified by adding wood preservatives. We modified the rice powder adhesive by adding three different types of anti-sapstain preservatives at three different concentrations to assess their anti-sapstin activity. The bonding strengths of the modified rice powder adhesives were still outstanding performance on all samples. Moreover, the plywood manufactured with the modified rice powder adhesive satisfied outdoor use requirement for ordinary plywood (KS F3101, Korean Standard). The results obtained showed that at least 3% of preservative should be added to the rice powder adhesive to obtain effective anti-sapstain activity.

• Journal of Conservation Science
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• v.35 no.4
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• pp.269-277
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• 2019

Seaweed extracts, namely carrageenan obtained from Grateloupia elliptica and algin obtained from Laminaria, were employed as adhesive agents to synthesize solid adhesives for paper. Carrageenan from Grateloupia elliptica with the highest adhesive strength and lgin from Laminaria with the highest compressive strength was selected. The selected carrageenan and algin were mixed in a ratio of 7:3, and the mixture was employed as an adhesive agent. At a high temperature, sodium stearate(used as a solidifying material) oxidized the seaweed extracts. Consequently, carrageenan and algin were added to the final manufacturing process. The adhesive strength of the final synthesized solid adhesive is found to be 3.02 MPa and the compressive strength is found to be 30.5 N. Compared to the adhesive strength (2.95 MPa) and compressive strength (30.11 N) of commercial solid adhesives, the obtained results indicate superior adhesion characteristics. Furthermore, the proposed adhesive is environment-friendly because the presence of volatile organic compounds, formaldehyde, and heavy metals(such as chromium, lead, and cadmium) were not detected. Moreover, when used, the flatness of paper was twice that of commercial solid paper adhesives. Hence, the proposed adhesive can provide excellent adhesion, stability, and usability.

• Journal of the Korean Wood Science and Technology
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• v.24 no.2
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• pp.42-45
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• 1996

A residue from the newsprint waste was investigated as a filler in adhesive for bonding southern pine plywood. The residue was prepared by drying the wet residue to 8% moisture content and grinding the dry material using a laboratory Wiley mitt with a 75-${\mu}m$(200-mesh) screen. The residue was compared to a commercial filler commonly used in structural plywood adhesives. A total of 48 three-ply panels. 12.7mm nominal thickness and 0.3 by 0.3 m in size, were fabricated at two press times(4 and 5 min) and three assembly times(20, 40 and 60 min). Evaluations of the residue were carried out by performance tension shear tests after two 4-hour boil accelerated aging tests on plywood. The test results included tension shear strength and estimated wood failure values. All plywood made with the residue filler were comparable to the control-bonded plywood. These results indicate that residue from the newsprint waste streams would be suitable as filler for plywood adhesives.

• Journal of Conservation Science
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• v.35 no.6
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• pp.681-688
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• 2019

In this study, the characteristics of natural and synthetic adhesives used in woodcraft were evaluated. The pattern of deterioration of wood and adhesives according to changes in temperature and humidity were compared. For materials, one type of anlmal glue, three kinds of polyvinyl acetate adhesives, one type of epoxy adhesive and one type of zelkova wood were selected. Characteristics of physical and chemical characteristics, weather resistance and drying speed assessment were carried out. The adhesion characteristic evaluation showed that the adhesion strength of anlmal glue and one type of polyvinyl acetate adhesive were 6.54 N/㎟ and 7.01 N/㎟, pH meter of anlmal glue and polyvinyl acetate adhesives was pH 7.03 and pH 3.32-3.59 which were range of available as an adhesive. According to the test results of weather resistance, epoxy adhesives had the highest decreasing value in adhesion strength after deterioration. In the reversible test of the adhesive, it was found to be highly reversible in NaOH, a soluble solvent excluding epoxy, but attention is required when using the wood since it may show discoloration during processing.

• Journal of the Society of Naval Architects of Korea
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• v.58 no.2
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• pp.66-72
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• 2021

As the demand for natural gas that satisfies environmental regulations increases, the quantities of natural gas cargo that carrier can load is also increasing. Natural gas is transported in a liquefied state at -163 ℃ to increase loading efficiency. Among several LNG CCS types, MARK-III types are generally adopted in terms of loading efficiency. The secondary barrier adhesives of the MARK-III, nevertheless, is subjected to tensile stress due to thermal contraction and tension in the environment. In terms of these reasons, local analysis of the adhesive to evaluate the stress state must be carried out. According to previous studies, local analysis is unavailable since material properties for secondary barrier adhesives have not been reported. Thus, in this study, the cryogenic tensile test and coefficient of thermal expansion of epoxy and polyurethane (PU15, PU45), which are most widely used at cryogenic temperatures, were experimentally analyzed. At cryogenic temperature, the mechanical behavior of the polyurethane adhesive was better than epoxy of the adhesive. the joint of FSB and epoxy adhesive of the secondary barrier has the maximum coefficient of thermal expansion difference at 25 ℃ and minimum at -150 ℃, respectively.

• Journal of Adhesion and Interface
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• v.21 no.4
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• pp.135-142
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• 2020

Recently, people's interest in eco-friendly plastics derived from nature to replace petroleum-based plastics is increasing due to environmental problems such as microplastics. In line with this trend, eco-friendly adhesives using natural materials and processes are also being developed in the adhesive field. Among them, maltose is a natural substance derived from starch and is the main component of starch syrup used as a food additive. Due to its lower molecular weight than starch, it is easily soluble in water, and above all, there is a possibility that it can be copolymerized with other monomers through solution polymerization. However, researches related to the application of maltose to adhesives are very rare. In this study, after modifying maltose using acrylic anhydride, the product was analyzed through FT-IR and H-NMR. And the modified maltose was copolymerized with two kinds of acrylic monomers. The synthesized adhesive was applied on the wood and the adhesive performance were investigated.