• Journal of the Korean Solar Energy Society
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• v.28 no.4
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• pp.10-16
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• 2008

The fire resistance of thermal insulation and interior finishing materials is recently much emphasized after the fire accident at the Icheon Cold Store in January 2008. Three kinds of thermal insulation are used in buildings. They are Organic, Non-organic and cellulosic insulation. Organic insulation such as polystyrene foam board and urethane foam has high thermal resistance but it has no fire resistance. While non-organic insulation such as rockwool and glassfiber has high fire resistance, it has lower thermal resistance than organic insulation. Cellulose insulation is primarily manufactured from recycled newsprint or cardboard using shredders and fiberizers. Despite of its environmental friendliness and high thermal resistivity, its domestic use has not much increased because of the prejudice that paper can easily burn. However, the cellulose insulation as a product is about 80 wt.% cellulosic fiber and 20 wt.% chemicals, most of which are fire retardants such as boric acid and ammonium sulfate. It is required to secure its fire safety for more consumption as a building insulation in Korea. Therefore, this study investigates the fire resistance of Korean cellulose insulation according to the rate of fire retardant and finally presents the optimum rate of fire retardant in cellulose as building insulation. The fire safety test was conducted according to the ASTM C 1485-00. The test results indicate that above 18 wt% of fire retardant is necessary to secure the fire safety of cellulose insulation.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.5
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• pp.289-294
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• 2002

Cellulose production by Acetobacter pasteurianus was investigated in static culture using four bioreactors with silicone rubber membrane submerged in the medium. The shape of the membrane was flat sheet, flat sack, tube and cylindrical balloon. Production rate of cellulose as well as its yield on consumed glucose by the bacteria grown on the flat type membranes was approximately ten-fold greater than those on the non-flat ones in spite of the same membrane thickness. The membrane reactor using flat sacks of silicone rubber membrane as support of bacterial pellicle can supply greater ratio of surface to volume than a conventional liquid surface culture and is promising for industrial production of bacterial cellulose in large scale.

• Journal of the Korean Society of Tobacco Science
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• v.5 no.2
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• pp.55-62
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• 1983

Four of non- isothermal methods evaluating kinetics have been studied by using differential scanning calorimetry (DSC) and thermogravimetry (TG) and applied for kinetics of the thermal decomposition of cellulose. It is concluded that the heating evolution methods with DSC and approximative methods with TC can lead to satisfactory kinetic analysis. Results calculating the reacting order and the activation energy of cellulose decomposition were 1/2 order and 42kcaB/mol, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.3 no.1
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• pp.27-31
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• 1990

Influences of plant phenolic acids and their possible metabolites(non-phenolic aromatic acids involved) in the rumen on the cellulolytic activity of mixed rumen populations were examined by a simple in vitro culture technique. Initial concentrations of aromatic acids were 1, 5, 10 and 20 mM/l. All the tested aromatic acids reduced microbial cellulose digestion especially at the higher initial concentration. P-Coumaric acid, ferulic acid and cinnamic acid, those having unhydrogenated propenoic side chain were more inhibitory than were 3-phenylpropinic acid and phloretic acid, those having hydrogenated propanoic side chain. Lag-time for cellulose digestion was prolonged by former three acids by 16 h. Apparent reduction in p-coumaric acid concentration was observed at 24 h when cellulose digestion began. Volatile fatty acid productions from cellulose fermentation were shifted by former three aromatic acids to produce more acetate and less propionate. This suggests that the selection of celluloytic organisms was induced by these aromatic acids.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.42 no.5
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• pp.62-66
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• 2010

Cellulosic materials were dissolved by NMMO(N-methylmorpholine-N-oxide) and CED (Cupriethylene diamine), respectively, to measure their DPs (degrees of polymerization) by using viscometer. We changed cellulose DPs by applying various amounts of low intensity electron-beam radiation to the cellulosic materials. NMMO is environmental-friendly, non-toxic, and biodegradable organic cellulose solvent and used industrially because of its high cellulose dissolving power and high solvent recovery ratio. The cellulose DP measurement results using these two different chemicals were correlated highly ($R^2$ >0.95). It was also found that cellulose with high DP was dissolved more easily in NMMO than CED. In addition, NMMO method gave more higher resolution in the measurement.

• Elastomers and Composites
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• v.55 no.3
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• pp.215-221
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• 2020

Silica/SBR (styrene-butadiene rubber) compounds are the primary constituents of tire treads. Furthermore, the excellent dynamic viscoelastic properties of silica lead to good fuel efficiencies. However, the silanol group on the surface of silica does not mix well with non-polar rubber because of its polarity. This incompatibility causes aggregation due to the occurrence of hydrogen bonding between the hydroxyl groups, thereby reducing the dispersibility of silica. Recently, the wet master batch (WMB) process has been applied to overcome these disadvantages, and research on silica dispersants that can be used in the WMB process has been increasing. In this study, we prepared silica/SBR compounds by using three types of eco-friendly cellulose-based dispersants in the WMB process, namely: cellulose-, sodium carboxymethyl cellulose, and nanocellulose-based dispersants. Subsequently, we compared the vulcanization characteristics, viscoelastic properties, and mechanical properties of the compounds. The silica dispersibility in the rubber compounds was improved with the addition of the nano-cellulose dispersant, resulting in the enhancement of the workability, hardness, tensile strength, and wear resistance of the SBR compound.

• Journal of the Korea Institute of Building Construction
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• v.3 no.3
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• pp.83-90
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• 2003

This study examines the material characteristics of fibers and their influences on reinforced concrete through the tests of reinforced concrete by the types of fibers including non-reinforced, steel, polypropylene and cellulose fibers and the test of compressive strength and reinforced concrete beam without shear reinforcement and consequently it obtains the following conclusions. As a result of conducting compressive strength by the types of specimens, fiber reinforced specimen with the highest compressive strength value at 28 days of age was cellulose fiber reinforced specimen as 280.4kgf/$\textrm{cm}^2$ and steel fiber specimen had the highest compressive strength of 250.7kgf/$\textrm{cm}^2$ at 180 days of age. In case of non-reinforced specimen, its compressive strength was 277.4kgf/$\textrm{cm}^2$ at 28 days of age and 273.1kgf/$\textrm{cm}^2$ at 180 days of age. Comparing the compressive strength of non-reinforced specimen to that fiber reinforced specimen showed that the compressive strength of fiber reinforced specimen was lower in the passage of age and the results of this experiment showed no effects of fiber reinforcement. As a result of testing reinforced concrete beam without shear reinforcement, ductility factors of specimens were 4.67 for non-reinforced specimen, 8.18 for steel fiber reinforced specimen, 6.20 for polypropylene fiber reinforced specimen and 5.49 for cellulose reinforced specimen, and it is found that steel fiber reinforced specimen was highest. When non-reinforced specimen and steel fiber reinforced specimen were compared, steel fiber reinforced specimen had higher ductility factor of about 75.2% than that of non-reinforced specimen.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.5
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• pp.711-720
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• 2009

Leaf fibers have many good properties; they are strong, long, cheap, abundant and bio-degradable. Since they, however, contain a great quantity of non-cellulose components, they have been used for the materials of mats, ropes, bags and nets rather than those of clothing. In this study, we investigated the characteristics of leaf fibers in order to promote the use of leaf fibers for the materials of clothing as well as develop the high value-added textile fibers. Leaf fiber plants including New Zealand Flax, Henequen and Banana plant, which have various nature and shape, were used. New Zealand Flax and Henequen leaves were cut from lower part of plants. Banana leaves and pseudo-stems were peeled and cut from the stem of Banana plants. First, the thin outer skins like film of leaves, veins and stems were removed before retting. The chemical retting had been processed for 1hour, at 100 in 0.4% $H_2SO_4$ aqueous solution(liquid ratio 50:1). Then, the retted leaf fibers had been soaked for 1hour, at room temperature in 0.5% NaClO solution(v/v) to remove the miscellaneous materials. We investigated the physical characteristics of three leaf fibers including the transversal and longitudinal morphology, the contents(%) of pectin, lignin and hemicellulose, the length and diameter of fibers, the tensile strength of the fiber bundles, and the fiber crystallinity and the moisture regain(%). The lengths of fiber from three leaf fibers were similar to their leaf lengths. The fiber bundles were composed of the cellulose paralleled to the fiber axis and the non-cellulose intersecting at right angle with the fiber axis. The diameters of New Zealand Flax, Henequen and Banana fibers were $25.13{\mu}m$, $18.16{\mu}m$ and $14.01{\mu}m$, respectively and their tensile strengths were 19.40 Mpa, 32.16 Mpa and 8.45 Mpa, respective. The non-cellulose contents of three leaf fibers were relatively as high as 40%. If the non-cellulose contents of leaf fibers might be controlled, leaf fibers could be used for the materials of textile fiber, non-wovens and Korean traditional paper, Hanjee.

• Journal of Nutrition and Health
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• v.17 no.4
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• pp.253-261
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• 1984

The effect of fiber sources on lipid metabolism was investigated in relation to the level of dietary fat. After rats were fed each diet for 4 weeks, all animals were sacrificed to collect the liver, and blood samples by heart puncture. Total lipid, total cholesterol, phospholipid and HDL- cholesterol were determined in serum. Total lipid and total cholesterol were also determined in liver. These results were compared with the histochemical appearances by the method of Oil red-O staining. Higher level of fat in the diet appeared to increase the total lipid levels in serum and more fat in the liver cells were shown from the high fat diet judging from the E.M. pictures. Phospholipid concentration in serum was greater in the rats of high fat groups than those of the control or non-fat groups. High fat level caused to decrease the HDL- cholesterol concentration in serum. Pectin decreased serum and liver lipids and the deposit of fat in the liver cells. HDL-cholesterol levels in serum was increased by pectin. Whereas the cellulose supplementation had no effect to reduce serum and liver total lipid levels, and cellulose did not decreased the deposit of fat in the liver cells. From these results, it is concluded that dietary fat levels led to changes in the lipid metabolism of rats and pectin may exhibit a lowering total lipid contents in serum and liver. Cellulose may slightly elevate serum and liver levels, or have no lowering effect.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.46 no.4
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• pp.37-43
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• 2014

The crystallinity and molecular weight of cotton linter need to be controlled to be more easily dissolved in NMMO during manufacture of clothing fabrics. Electron beam irradiation and sulfuric acid treatment were used as pre-treatment to reduce molecular weight of cotton linter more efficiently, and after the pre-treatment, peroxide bleaching was followed in alkaline condition. After those processes, the crystalline indices of the cotton linters were measured by XRD method, and other properties such as their alpha cellulose contents and degree of polymerization were measured. It was found that the crystallinity index of cotton linter was decreased as the irradiation of electron beam increased while increased as the dose of sulfuric acid increased. These results strongly suggested that electron beam damaged the crystalline structure of the cellulose directly while sulfuric acid dissolved mostly non-crystalline area of the cellulose structure.