• Proceedings of the Korean Society of Rheology Conference
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• 2003.05a
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• pp.107-110
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• 2003

• Journal of Korean Society of Forest Science
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• v.24 no.1
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• pp.45-52
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• 1974

This study was carried out to examine the subsitution possibility into water soluble amino resins instead of phenolic resin as a sizing material for the strength increase on the wet forming hardboard. The properties of hardboard, manufactured with amino-resins based urea, melamine, formaline, and methanol which were low priced domestic products, were examined in comparison with those of hardboard treated with phenolic resin. In this study by the results and discussions, it may be summarized as follows: 1. Amino-resins are able to be substituted for the phenolic resin as a good sizing material for strength increase in the manufacture of wet forming hardboard. Under the considerations of economic advantages and properties of hardboard, modified urea-melamine resin was given a best results. 2. The specific gravities of hardboard that were treated with phenolic resin was equal to that treated with modified amino type resin, and in case of urea-melamine resin, the specific gravity value were lowest among them. 3. The results of moisture contents were satisfied the standard which calls for 13 percent or below. There were no differences in moisture contents between hardboards, treated with melamine resin and modified urea-melamine resin but phenolic resin. The moisture contents of hardboard treated with phenolic resin was shown the lowest. 4. The water absorption of hardboard treated with phenolic resin was greater than those treated with amino resins, and to satisfy the standard of water resistance, the treatment of 2 percent paraffin wax emulsion was needed in this case. There were no differences in water absorptions between hardboards, treated with melamine resin and modified urea-melamine resin. To satisfy the standard of water resistance in this case the treatment of 1 percent paraffin wax emulsion was shown good results. 5. The differences among the flexural strength in using tested three adhesives were significant. The flexural strength were shown the signification by order of melamine resin, modified urea-melamine resin, and phenolic resin. In all cases to satisfy the standard of flexural strength, the treatment of 3 percent sizing materials for strength increase was needed.

• Composites Research
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• v.35 no.4
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• pp.288-297
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• 2022

This study investigated the effect of addition of zirconia(zirconium oxide) powder on the curing behavior of phenolic resins. The heating rate controlled curing and isothermal curing behaviors of the phenol resin according to the content of the zirconia powder were analyzed. The viscosity and thermal decomposition characteristics of the phenolic resin with the zirconia content were also examind. From the DSC analysis, the degree of cure and the rate of cure were obtained. Finally, the activation energy for the cure reaction were calculated from the DSC data of the zirconia added phenolic resin. As a found, the higher the zirconia content, the longer the curing was delayed and the greater the activation energy required for curing. Additionally, the TGA result that as the content of zirconia increased, less weight loss was observed. The surface tackiness of the Carbon/Phenol prepreg was partially changed according to the zirconia content, but had no significant effect.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1999.06a
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• pp.92-100
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• 1999

Friction characteristics of automotive friction materials according to the types of phenolic resin were investigated by using a pad-on-disk type friction tester. Four different simplified friction materials bound with Bakelite$^{TM}$ and Xylok$^{TM}$ phenolic resin were studied in this work. Two different modes of drag test(constant initial temperature test and constant interval test) were employed to analyze the effects of the binders on friction characteristics. Friction materials containing modified Xylok$^{TM}$ resin showed good heat resistance and friction stability. The results also showed that aramid fiber played important roles in improving friction stability and weard wear

• 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.

• Journal of the Korean Graphic Arts Communication Society
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• v.7 no.1
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• pp.65-72
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• 1989

Modified phenolics can have a retarding effect on the gelation of wood oil. Modified phenolic resins can be used in media for paint, varnishes, primers, overprinting varnishes, litho, letterpress and rotogravure inks. Varnishes based on rosin phenolic are faster drying, have better durability, are harder and glosser, and have greater resistance to water than ones based on ester gums. These physical properties is concerned with molecular weight distribution of rosin modified phenol resin. This paper was studied about molecular weight distribution of rosin phenolics which were prepared between $130~250^{\circ}C$. The results were as follows: 1) Average molecular weights inereased with increasing reaction temperature. 2) $M_w/M_n$ were from 3.43 to 46.44 with increasing reaction temperature and so the molecular weight distributions were changed from random distribution to broad distribution. 3) The relation ship between intrinsic viscosity and weight average molecular weight was follows: $[{\;}{\;}]={\;}1{\times}{\;}10^{-6}M_w,{\;}M_w=M_w$ 4) Esterification reaction between the acid group of rosin and polyol was started about $230^{\circ}C$$.

• Journal of the Korean Graphic Arts Communication Society
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• v.24 no.2
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• pp.11-24
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• 2006

The Lithographic ink is composed of pigment, vehicle and additives. In especially, the vehicle is the most important element and consist of vegetable oils, mineral oils and resins. Varnishes have to resist certain forms of chemical and physical attack during ink manufacturing process and printing process So this varnish cooking is very important. In this paper, effects of cooking conditions of varnish using phenolic modified rosin ester on physical properties of the vehicle were studied. The varnish cooked according to temperature and time were compared in order of average molecular weight by the GPC method. and the rheological properties were found by rotational rheometer. And the emulsion behavior were compared by high speed emulsification tester which were set on 1200 rpm and $40^{\circ}C$ temperature (Novomatics Lithotronic). We displayed viscosity against tack(Inkometer Thwing-Albert M-106) by diagram.

• Journal of the Korea Institute of Military Science and Technology
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• v.23 no.5
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• pp.475-484
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• 2020

Individual curing process of each layer in two resin composites can be caused the separation between two layers. In this study, co-curing process for two resin composites is suggested to improve the inter-layer bonding. Glass fiber reinforced composites with phenolic and epoxy resins were manufactured by co-curing process, and several types of glass/phenolic composites were considered to confirm the application on two resin composites. Experiments for smoke resistance, scratch resistance and flexural strength were carried out to verify requirements corresponding to thermal and mechanical environments. It was validated that two resin composites with phenolic resin impregnated prepreg exhibits good thermal and mechanical characteristics, and it can serve as highly effective composite structures in aerospace and many industry areas.

• Journal of Korean Society of Forest Science
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• v.30 no.1
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• pp.19-29
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• 1976

The fiberboard and paper mills in this country are much affected by the price hikes and shortage of phenolic resins, since phenolic acid as a raw material depends on imported good. It is prerequisite to fiberboard industry to help replace with other sized and stabilize the prices and supply of them, improving the quality of boards. Thus, the present study was carried out to examine the effect of strength increasing sized such as urea formaldehyde resin (anion and cation type) and urea melamine copolymer resin, on the quality of the wet forming hardboard, and comparing them with two types of proprietary modified melamine resins, and ordinary size, phenol resin. The Asplund pulp was prepared from wood wastes mixed with 20 percent of lauan and 80 percent of pines as a fibrous material. After sizing agents were added at a pH of 4.5 for 10 minutes with alum in the beater, the stock was made in the form of wet sheet, prepared, and then performed by hot pressing cycle: $180^{\circ}C$, $50-6-5kg/cm^2$, 1-2-7 minutes. The properties of hardboard were examined after air conditioning. The results obtained are summarized as follows: 1. There is a significant difference in specific gravity among hardboards that were treated with strength increasing resins, but no difference is effected by the increase in the resin content. In the case of modified melamine resin, its specific gravity is highest. The middle group comprises cation type of urea resin, anion type of urea resin, and acid colloid of urea-melamine copolymer resin. The lowest is phenolic resin. 2. The difference of the moisture content of hardboard both by the resins and by the amount of each resin applied is significant. The moisture content of hardboard becomes lower along with the increase of each resin content, but there is no difference between 2 and 3 percent. 3. For water absorption, there is a significant difference both in the adhesives used and in the amount of paraffin wax emulsion. The water resistance becomes higher inn proportion to the content of the paraffin wax emulsion. To satisfy KS F standards of the water resistance, a proprietary modified melamine resin (p-6100) and modified cation type of urea resin (p-1500) do not require any paraffin wax emulsion, but in the case of anion type of urea resin, cation type of urea resin, and urea-melamine copolymer resin, 1 percent of paraffin wax emulsion is needed, and 2 percent of paraffin wax emulsion in the case of phenolic resin. 4. The difference of flexural strength of hardboard both by the resins and by the amount of each resin is significant. Modified melamine resin shows the highest degree of flexural strength. Among the middle group are urea-melamine copolymer resin, p-1500, anion type of urea resin, and cation type of urea resin. Phenolic resin is the lowest. The cause may be attributable to factors combined with the pressing temperature, sizing effect, and thermal efficiency of press platens heated electrically. 5. Considering the economic advantages and properties of hardboard, it is proposed that urea-melamine copolymer resin and cation type of urea resin be used for the development of the fiberboard industry. It is desirable to further develop the modified urea-melamine copolymer resin and cation type of urea resin through continuous study.

• KSBB Journal
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• v.24 no.5
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• pp.415-419
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• 2009

In this study, the detoxification methods were evaluated for the removal of fermentation inhibitors from synthetic solution containing the composition similar to the lignocellulosic hydrolysate. The enzyme peroxidase and laccase were used as a biological treatment method. The physico-chemical methods such as adsorption and ion exchange were applied by using activated charcoal and ion exchange resins. The enzyme peroxidase showed a excellent removal of phenolic compounds. The 5-HMF and furfural were completely removed by activated charcoal. The anion exchange resin showed a good result for detoxification of acetic acid. The activated charcoal and ion exchange resins lead to a loss of sugars more or less. The choice of detoxification method must be made after considering the composition and inhibitors in hydrolysates.