• Polymer(Korea)
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• v.37 no.5
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• pp.625-631
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• 2013

Mucoadhesive property is the major function as an adhesive for medical devices, and therefore, these days many researches have conducted to develop polymers having this property. Recently, biomimetic technology has been used for developing mucoadhesive polymers. Among many technologies, mussel-inspired approaches have received noticeable attention because of its thread's strong adhesive characteristics. In this study, we synthesized mucoadhesive biomimetic polymers employing catechol structures which are abundant in mussel adhesive proteins, and their structures and molecular weights were characterized by using nuclear magnetic resonance spectroscopy and gel permeation chromatography. To evaluate in vitro mucoadhesive strength, the sheet type of the small intestinal porcine submucosa was prepared. Compared to commercial fibrin glue adhesives, catechol-containing mucoadhesive polymers showed enhanced adhesive strength. The study of adhesive strength with considering diverse factors, such as temperature, pressure, and oxidant amount indicated that mussel-inspired mucoadhesive polymer could be a promising candidate for an adhesive in various biomedical applications.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.46 no.4
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• pp.44-53
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• 2014

This research were aimed at developing starches which have high preservability and high bonding strength from corn starch, modified cationic and oxidized corn starches, as compared to the fermented wheat starch. On the lining that attaching the base paper on the back of the work with paste, the coating weight was determined by the solid contents of the paste rather than the viscosity of paste. Adhesive strength and stiffness were also determined by the solid contents of the paste. Corn starch had lower solid contents, higher viscosity, and higher adhesive strength than other starches. In the iodine stain to the surface of peeled base paper off, paste deeply penetrated into the traditional Hanji than modern Hanji. And oxidized starch paste deeply penetrated into the paper layer than the cationic starch.

• Journal of the Korean Wood Science and Technology
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• v.51 no.2
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• pp.81-97
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• 2023

The aim of this study were to evaluate tannin resorcinol formaldehyde (TRF) for the preparation of cross-laminated timbers (CLTs) made from fast-growing tree species and to analyze the physical and mechanical properties of CLTs. TRF copolymer resin was prepared by using the bark extracts of Swietenia mahagoni (L.) Jacq. It was observed that the TRF adhesive possessed less solid content (23.59%), high viscosity (11.35 poise), and high pH values (10.0) compared to the standard phenol resorcinol formaldehyde. The TRF adhesive was applied to produce CLTs with the addition of 15% tapioca and flour as an extender. The six-layered CLTs were produced from sengon (Falcataria moluccana Miq.), jabon [Anthocephalus cadamba (Roxb) Miq.], coconut (Cocos nucifera L.), and the combination of coconut-jabon and coconut-sengon wood. The analysis of variance revealed that the layer composition of CLT significantly affected the physical and mechanical properties of the beam. While the modulus of rupture met the standard, the moisture content and modulus of elasticity values did not fulfill JAS 1152-2007. All of the CLTs produced in this study demonstrated low formaldehyde emission, ranging from 0.001 mg/L to 0.003 mg/L, thereby satisfying the JAS 1152 for structural glue laminated timber.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.3
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• pp.277-290
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• 2012

Dental implants are universal restorative method on edentulous site in oral cavity and generally recognized by patients as well as clinicians. Rapid bone resorption of labial portion of maxillary anterior area is performed due to dental trauma, chronic periodontitis, and so on. Accordingly, Implants on maxillary anterior alveolar ridge with narrow labiopalatal width would lead to bony defects of dehiscence or fenestration. In this case, guided bone regeneration procedure is used to augment maxillary anterior alveolar ridge. It can have mechanical and biological advantages to mix tissue adhesive with bone graft materials in guided bone regeneration procedure. In these cases, when the dehiscence or fenestration defects was occurred by dental implants on maxillary anterior alveolar ridge with narrow labiopalatal width, guided bone regeneration procedures were performed with various combination of particle bone graft materials(allograft, xenograft, and alloplast) mixed with fibrin glue, excepting autogerous bone. We reported that all of 4 cases showed favorable alveolar ridge augmentations.

• Journal of the Korean Wood Science and Technology
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• v.47 no.3
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• pp.253-264
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• 2019

This study characterized the chemical compounds in tannin from mangium (Acacia mangium) bark extract and determined the physical-mechanical properties of glued laminated timber (glulam) made from sengon (Falcataria moluccana), jabon (Anthocephalus cadamba), and mangium wood. The adhesives used to prepare the glulam were based on mangium tannin and phenol resorcinol formaldehyde resin. Five-layer glulam beams measuring $5cm{\times}6cm{\times}120cm$ in thickness, width, and length, respectively, were made with a glue spread of $280g/m^2$ for each glue line, cold pressing at $10.5kgf/cm^2$ for 4 h and clamping for 20 h. Condensed mangium tannin consisted of 49.08% phenolic compounds with an average molecular weight of 4745. The degree of crystallinity was 14.8%. The Stiasny number was 47.22%. The density and the moisture content of the glulams differed from those of the corresponding solid woods with mangium having the lowest moisture content (9.58%) and the highest density ($0.66g/cm^3$). The modulus of rupture for all glulam beams met the JAS 234-2003 standard but the modulus of elasticity and the shear strength values did not. Glulam beams made with tannin had high delamination under dry and wet conditions, but glulam made from sengon and jabon wood met the standard's requirements. All glulam beams had low formaldehyde emissions and were classified as $F^{****}$ for formaldehyde emissions according to the JAS 234 (2003) standard.

• Applied Biological Chemistry
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• v.39 no.2
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• pp.123-126
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• 1996

Simple and rapid method of purification of plasma proteins from bloods of slaughtered animals was developed and the proteins were applied to plywood products as a blood 히ue to utilize waste materials. Plasma protein was obtained by adding 2% trichloroacetic acid (TCA) or 0.6 N HCI as optimal concentration to the supernatant, after centrifugation of bloods. Molecular properties of beef and pig plasma proteins were examined on SDS-PAGE. Application of blood glue to plywood was quite satisfactory compared to the synthetic amino resin by tensile-shear test for the strength of adhesive bonding.

• Journal of the Korean Wood Science and Technology
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• v.48 no.6
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• pp.907-916
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• 2020

This research was conducted to investigate the linear expansion and resistance properties of a composite board (com-ply). This board was made of medium-density fiberboard (MDF) laminated using avocado (Persea americana), mahogany (Swietenia mahogani), and pine (Pinus merkusii) veneers. These three types of veneers were laminated on both surfaces of the MDF using adhesives, namely, epoxy and isocyanate. Glue (250 g·m^-2) was spread on the surface, followed by cold press for 3 h with an applied pressure of 15 kg·cm^-2. The research result revealed that com-ply exhibited an increased dimensional stability compared with MDF, indicated by reduction in water absorption, thickness swelling, and linear expansion. The com-ply made of the pine veneer and isocyanate adhesive exhibited high density, water absorption, thickness swelling, and screw withdrawal load. The com-ply that exhibited the strongest resistance to drywood termite attacks was the one made of the mahogany veneer and isocyanate adhesive. Moreover, the com-ply that exhibited the biggest weight loss (3.6 %) was made of the pine veneer and epoxy adhesive. The results of this research may facilitate in manufacturing com-ply using the selected veneer and adhesive without the application of hot press.

• Journal of the Korean Society of Costume
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• v.57 no.9
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• pp.67-75
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• 2007

The purpose of this research is to conserve of golden decoration(Jikgeumdan) of Chima(skirt) and Jeogori(Korean jacket) of the costumes excavated from Hangju Gi' tomb(17th Century) of Joseon dynasty$(1392{\sim}1910)$ and to focus on the development of conservation skill to prevent flakings of gold leaves in gilt paper strips. Up to the present, in case of golden decorations of costumes excavated from tombs of Joseon dynasty, some of gold leaves in gilt paper strips of costumes were flaked away by deterioration of adhesives in tombs. However, most of gold leaves were flaked away and totally lost by wet cleaning for eliminating contaminants after excavation. In order to prevent flaking, preliminary experiments for re-adhesion of gold leaves have been carried out. Firstly, simulation was performed using gold leaf which was available in the market. Adhesives used in this research were water-soluble adhesives(hide glue(cow, rabbit), glue made from air bladders of sciaenoid fish and Primal AC-3444 of acrylic emulsion) and solvent-soluble adhesives(acrylic adhesive Paraloid B-67 and B-72). Because of difficulty in wetting and spreading of adhesive solutions into the interface between gold leaf and Korean paper, water-soluble adhesives were not proper for adhesion of gold leaf and Korean paper. Solvent-soluble adhesives were easily infiltrated into interface between gold leaf and Korean paper and the adhesive force was also satisfied. From this result, the researchers chose more flexible Paraloid B-72$(Tg\;40^{\circ}C)$ 1% solution than Paraloid B-67$(Tg\;50^{\circ}C)$ for adhesion of gold leaf and Korean paper. Secondly, using Paraloid B-72 1% solution, the estimations of re-adhesions of gold leaves in gilt paper strips of Jeogori were carried out. When Paraloid B-72 1% solution was injected three times into the interface between gold leaf and Korean paper, the re-adhesion was most effective. On the basis of the results in these preliminary experiments, re-adhesions of gold leaves in gilt paper strips of Chima and Jeogori were carried out on condition of three times injections of Paraloid B-72 1% solution before wet cleaning. After wet cleaning, the most of the gold leaves were survived, which was confirmed by both the examination with the naked eye and the microscopic examination.

• Korean Journal of Heritage: History & Science
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• v.46 no.3
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• pp.150-171
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• 2013

The most important part of conservation treatment of murals is to preserve them against the risk of a damage by injecting fixative into them when the painting loses its cohesion or powderization of pigments occurred due to occurrence of cracks inside the painting layer. However, studies on the stability of fixative used for painting layers of murals are still insufficient. This study manufactured a mural as a specimen and colored it with four kinds of pigments including oyster shell white, cinnabar, malachite and red clay and applied four kinds of fixative, including, Paraloid $B-72^{(R)}$, Caparol-$binder^{(R)}$, glue and Hydoxypropyl $cellulose^{(R)}$. artificially generated environmental changes in temperature, humidity and ultraviolet rays which may occur after the completion of conservation treatment. Then the changes in physical properties were observed in multifaceted ways such as color stability, contact angle, brilliance, adhesive strength and surface. As a result, this study found that ultraviolet rays and hot?humid environment have a large impact on color stability causing changes in brightness and chroma of all painting layers where the fixative were applied, except for oyster shell white and are considered the main factors of decomposition by accelerating the aging process of fixatives applied. In comparison to the synthetic resins that were also tested in this study, the traditional glue showed satisfactory results in terms of color stability and influence preservation and the hydrophile property. As it showed exceptionally outstanding adhesive strength in all painting layers in the aspect of adhesive strength, it is considered to be highly stabile for the fixation treatment of painting layers of mural.

• Journal of the Korean Wood Science and Technology
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• v.46 no.2
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• pp.143-148
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• 2018

The aim of this research was to determine the physical and mechanical properties of glued laminated lumber (glulam) made from jabon (Anthocephalus cadamba) and pine (Pinus merkusii). Three layers of lamina from each wood species were bonded using isocyanate adhesive with a glue spread of $280g{\cdot}m^{-2}$ and then pressed using cold press with a specific pressure of 1.47 MPa. Samples had dimensions of $3cm{\times}6cm{\times}100cm$ (thickness, width, and length, respectively). Glulam properties were tested based on Japanese Agricultural Standard (JAS) 234-2003. The results showed that the density of glulam was $0.36g{\cdot}m^{-3}$ for jabon and $0.73g{\cdot}m^{-3}$ for pine. The moisture content of all glulams fulfilled the JAS standard. The mechanical properties of pine glulam fulfilled the JAS standard in all tests, whereas jabon glulam fulfilled the standard in the modulus of rupture and shear tests.