• Journal of Korea Foresty Energy
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• v.24 no.1
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• pp.28-32
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• 2005

This study was performed to find a new use of wood tar from the manufacturing process of wood charcoal. Plywoods made of phenol adhesives mixed with wood tar were manufactured, and physical, mechanical properties and formaldehyde emission were investigated. Plywoods made of phenol adhesives mixed with wood tar were almost same as an original phenol adhesive in physical and mechanical properties and tensile-shear adhesive strength of the plywood was higher than the original one in both non-waterproof and waterproof tests. Formaldehyde emission was lower as the amount of wood tar increased in phenol adhesive.

• Korean Chemical Engineering Research
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• v.52 no.1
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• pp.63-67
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• 2014

The effects of reactant composition on the particle size distribution, synthetic yield, and density of Phenol-formaldehyde bead were examined in the synthesis of resol-type phenolic resin. Decrease of the content of DI water as dispersion media can increase the viscosity of suspension, which may cause the difference of particle size distribution and aggregation. The average particle size of synthesized beads was also decreased with the increasing content of stabilizer which can affect the interfacial area. The amount of crosslinking agent showed no effect on the size distribution and synthetic yield, but it made a decrease in the density of synthesized bead due to the macropore in the bead.

• Applied Chemistry for Engineering
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• v.16 no.2
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• pp.288-291
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• 2005

Resol type phenol-formaldehyde (PF) resin was synthesized by addition reaction of formaldehyde (F) and phenol (P). And the PF resin was synthesized by condensation reaction in which water was removed. In this work, we studied the influence of experimental parameters in the addition reaction, such as F/P mole ratio, amount of catalyst, reaction temperature, reaction time, and so on. Also, we studied the influence of molecular weight and viscosity of PE resin as a function of condensation time. As a result, in addition reaction, the reaction time decreased remarkably as the catalyst concentration increased, and the time decreased with increasing reaction temperature at a constant catalyst concentration. Also, in condensation reaction, the viscosity of resol type PF resin increased from 1500 to 9000 cps as a function of condensation time; molecular weight showed from 500 to 1100 g/mol.

• Journal of the Korean Chemical Society
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• v.17 no.1
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• pp.60-66
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• 1973

When m-phenylenediamine (MPD) or m-aminophenol (MAP) was treated with formaldehyde(F), under $N_2$ stream, at the temperature $-5\sim0^{\circ}C$, addition condensation occurred and insoluble resins formed immediately. Under the same reaction conditions m-phenylenediamine, m-aminophenol and formaldehyde also easily copolycondensed and insoluble MPD-MAP-F type copolymer formed. MPD-MAP-F type copolycondensed resin was superior in both heat-resistant property and adsorptivity of Bromophenol Blue or Methylene Blue than the MPD-F and MAP-F type resins. From the result of TGA, under $N_2$stream, MPD-MAP-F resin showed about $40\%$ weight loss at $800^{\circ}C$, and this type of resin 1g adsorbed 308mg of Bromophenol Blue.

• Journal of the Korean Wood Science and Technology
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• v.37 no.4
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• pp.388-396
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• 2009

In our study, the potential of okara as an ingredient of new bio-based adhesives was investigated for the production of fancy-veneered flooring boards. Okara was hydrolyzed by 1% sulfuric acid solution (AC) and 1% sodium hydroxide solution (AK). Phenol formaldehyde (PF) prepolymers were prepared as a cross-linker of okara hydrolyzates. Then, okara-based adhesive resins were formulated with 35% AC, 35% AK and 30% PF prepolymer on solid content basis. The adhesive resins were applied on high-density fiberboards (HDF) with the spread rate of $300g/m^2$. After that, oak fancy veneers are covered on the HDF, and then pressed with the pressure of $7kg/m^2$ at $120^{\circ}C$. The experimental variables were three mole ratios of formaldehyde to phenol (1.8, 2.1, 2.4), three assembly time (0, 10, 20 min), and two press time (90 sec, 120 sec), respectively. The fancy-veneered high-density fiberboards were tested by dry tensile strength, glueline failure by wetting and formaldehyde emission. Tensile strength of the boards exceeded the requirement of KS standard. The formaldehyde emissions were approached at the E0 level specified in KS standard. Based on these results, okara can be used as an ingredient of environmentally friendly adhesive resin systems for the production of flooring boards.

• Journal of the Korean Chemical Society
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• v.20 no.3
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• pp.240-243
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• 1976

A lignin resin, synthesized from the reaction of lignin, phenol and formaldehyde using NaOH as catalyst, showed a strong adhesive property. From a series adhesive strength test it has been shown that the synthetic resin can be used as a good adhesive material for wood.

• Journal of the Korean Chemical Society
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• v.41 no.10
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• pp.524-534
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• 1997

Analysis of additives in cured rubber is often a difficult task for analytical chemists because of a wide variety of complex components. Conventional analyses of additives and rubbers have been done in multistep, off-line processes with large sample size and extensive sample preparations. The coumarone-indene resin, resorcinol-formaldehyde resin, and prevulcanization inhibitor have been characterized by their pyrolysis pathways and mass spectra of characteristic pyrolyzates. Pyrolysis Gas Chromatography/Mass Spectrometry (Py-GC/MS) was used in the identification of additives without any sample pretreatment. This result shows that several organic additives in cured rubber can be directly analyzed.

• 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.

• Korean Journal of Heritage: History & Science
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• v.51 no.4
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• pp.66-83
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• 2018

This article focuses how the materials of hatstrings of the 19th to 20th century gat, the Korean top hat for men among the collections of National Folk Museum of Korea, was transformed after port opening treaties with overseas since 1876. As a result of analyzing the materials of the hatstrings, amber, tortoiseshell, wood and bamboo as the traditional materials were used, and ivory, glass (soda glass, lead glass, alkali mixed glass) and plastics (cellulose nitrate, phenol-formaldehyde, polystyrene, acryl) were newly used for the hatstrings. Bamboo, wood and amber were the most frequently used materials. Bamboo was mainly used for the pipe of hatstring and were combined with beads and central decorations of other materials. This shows the trend of bamboo hatstring according to the simplification of the clothing and the culture by Regent Heungseon Daewongun. Ambers were used in the central decorations and beads and the origin of ambers was baltic amber just like the amber relics found in Korea. Compositions of glass were soda glass and alkali mixed glass which were excavated or handed down in Korea from ancient times to Joseon dynasty. But in the case of lead glass, Na2O was detected and it is considered to be a new type lead glass for crafts which came from overseas after port opening since 1876 because it showed the characteristic that it deviates from the lead glass component found in Korea. Plastics such as cellulose nitrate and phenol-formaldehyde were used as new synthetic materials to replace traditional materials such as tortoiseshell, amber, and coral as in the West. Cracks, crazing, crumbly and yellowing of cellulose nitrate of hatstrings were observed by deterioration. The survey of the materials of the 19th to 20th century hatstrings among the collections of National Folk Museum of Korea showed that the introduction of new materials such as glass and plastics were used to replace natural materials such as tortoiseshell and amber along with the use of traditional materials after port opening since 1876.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.2
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• pp.41-51
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• 2004

Recycled plastic containers, so-called 'Tarai' in Korea which are often used as food containers, were collected from 23 domestic manufacturers. Then, their components were analyzed to find out whether they are safe for the use of food-contact material, to meet the standards and specifications of Korean hygienic regulations, the 'Food Code.' The components of the material were analyzed by using Fourier Transform-Infrared (FT-IR), Differential Scanning Calorimeter (DSC), and Elementary Analyzer (EA). The analysis of the FT-IR and the DSC showed that the main component of the samples was polyethylene. Furthermore, the analysis of the EA for 'Tarai' sample revealed the same ratio of C and H elements as in the case of polyethylene which was 1 to 2. Phenol and formaldehyde were not detected in all the samples. As for the antioxidant tests, Irganox 1010, Irganox 1076 and Irganox 1330 were detected in various samples. With regard to the material test for heavy metals, 7 out of 23 samples exceeded the limit value of 100 mg/kg in lead contents. No standard and specification is yet prescribed in the 'Food Code' for the material of 'Tarai' as plastic containers for food. This study suggests that the use of 'Tarai' as a food container should be strictly controlled.