• Elastomers and Composites
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• v.50 no.2
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• pp.132-137
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• 2015

A self actuated photocatalyst $Weltouch^{(R)}$ used to the remove the odor gases generated in the foaming process of shoes insole was prepared by sol-gel method and studied its property. Specially, with mixing $Weltouch^{(R)}$ in the foaming process of shoes insole, the physical functionality such as specific gravity, hardness, elongation, compression set was studied. The physical functionality of shoes insole was no variation by added $Weltouch^{(R)}$. The odor gases generated in the foaming process of shoes insole was detected to be reduced to 60~80% by self actuated photocataylst $Weltouch^{(R)}$ even in the dark conditions, which was observed for both anatase and rutile phase.

• Elastomers and Composites
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• v.41 no.2
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• pp.88-96
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• 2006

The self-sealing rubber material for a fuel cell which has self-sealing ability, in case of fuel leakage, was studied. Cure characteristics, density, swelling, and surface morphology of foamed natural rubber were investigated with carbon black and with processing oil within the range of $10{\sim}30phr$. The rheological properties indicated that the value of $ts_2$ and the value of $Tc_{90}$ were increased with increasing a content of processing oil, while carbon black did not show a similar trend. A difference in density by foaming was decreased to one fifth scale compared to the initial value. According to the swelling test of foamed natural rubber in fuel C, isooctane and toluene, all the self-sealing action was finished in two minutes. From the SEM image for the surface of rubber compounding, a foaming by sodium bicarbonate was found to be unequal and consecutive foaming cell.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.203-204
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• 2019

Recently, exposed concrete designs have been placed everywhere due to increased interest in indoor residential environments. In addition, in order to overcome the disadvantages of litracon, which was developed by mixing optical fiber, LEFC(Light Emotion Friendly Concrete) was developed in Korea, which improved unit price and constructivity by inserting hard acrylic rods. LEFC, using foaming agent and lightweight aggregate for light weighting, has disadvantages that decrease mechanical properties, and thus improved mechanical properties by using ultra-high performance concrete. Also, due to the characteristics of UHPC materials, it showed excellent self-consolidating performance. Considering these characteristics, a LEFC mold with pattern design was developed. The LEFC blocks were built so that pattern shapes could be seen and these were applied on-site to Sewoon plaza, located in Seoul.

• Korean Journal of Food Science and Technology
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• v.9 no.2
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• pp.123-130
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• 1977

A laboratory study was made to develop a simple and economic model method for the systematic determination of functional properties of 'Soy Protein Isolates (SPI)' prepared from defatted soybean meal. These are required to evaluate and to predict how SPI may behave in specific systems and such proteins can be used to simulate or replace conventional proteins. Data concerning the effects of pH, salt concentration, temperature, and protein concentration on the functional properties which include solubility, heat denaturation, gel forming capacity, emulsifying capacity, and foaming capacity are presented. The results are as follows: 1) The yield of SPI from defatted soybean meal increased to 83.9 % as the soybean meal was extracted with 0.02 N NaOH. 2) The suitable viscocity of a dope solution for spinning fiber was found to be 60 Poises by using syringe needle (0.3 mm) with 15 % SPI in 0.6 % NaOH. 3) Heat caused thickening and gelation in concentration of 8 % with a temperature threshold of $70^{\circ}C$. At $8{\sim}12\;%$ protein concentration, gel was formed within $10{\sim}30\;min$ at $70{\sim}100\;^{\circ}C$. It was, however, disrupted rapidly at $125\;^{\circ}C$ of overheat treatment. The gel was firm, resilient and self-supporting at protein concentration of 14 % and less susceptible to disruption of overheating. 4) The emulsifying capacity (EC) of SPI was correlated positively to the solubility of protein at ${\mu}=0$. At pH of the isoelectric point of SPI (pH 4.6), EC increased as concentration of sodium chloride increased. Using model system$(mixing\;speed:\;12,000\;r.p.m.,\;oil\;addition\;rate:\;0.9\;ml/sec,\;and\;temperature\;:\;20{\pm}1\;^{\circ}C)$, the maximum EC of SPI was found to be 47.2 ml of oil/100 mg protein, at the condition of pH 8.7 and ${\mu}=0.6$. The milk casein had greater EC than SPI at lower ionic strength while the EC of SPI was the same as milk casein at higher ionic strength. 5) The shaking test was used in determining the foam-ability of proteins. Progressively increasing SPI concentration up to 5 % indicated that the maximum protein concentration for foaming capacity was 2 %. Sucrose reduced foam expansion slightly but enhanced foam stability. The results of comparing milk casein and egg albumin were that foaming properties of SPI were the same as egg albumin, and better than milk casein, particularly in foam stability.

• Journal of the Korean Society of Safety
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• v.32 no.1
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• pp.108-114
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• 2017

According to an increase in demand for polyurethane soft foam for thermally insulated containers, the purpose of this study is based on redefining existing rigid polyurethane foam insulation KS standard which has been limited to building material-based authentication techniques. Since there are arising concerns of consumer rights and safety due to humidifier fungicides and urethane track incidents, there are elements to be further researched on rigid polyurethane foam insulation for refregerated containers. Thus, we reviewed the prior standards for rigid polyurethane foam insulation and verified the validity of certification testing method for the new standard with self-foamed polyurethane.

• Elastomers and Composites
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• v.55 no.4
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• pp.300-305
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• 2020

In recent times, polymeric foams have been popularly used in various applications. To meet the demand for these applications, polymer foams with excellent mechanical and thermal properties are required. In particular, silicone foam has gained significant attention owing to its superior thermal properties and low density. In this study, the mechanical and thermal properties of silicone foams filled with wollastonite were investigated. A maximum tensile strength of 98.3 kPa was obtained by adding 15 phr of wollastonite. The specific gravity did not exhibit a marked difference up to 10 phr, but it increased substantially above 15 phr wollastonite. Thermogravimetric analysis indicated that adding wollastonite to the silicone foam increased both the amount of residue and the thermal decomposition temperature. The morphologies of the silicone foams filled with wollastonite were observed by scanning electron microscopy.

• Advances in concrete construction
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• v.11 no.2
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• pp.151-161
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• 2021

The major shortcoming of concrete in most of the applications is its high self-weight and thermal conductivity. The emerging trend to overcome these shortcomings is the use of foam-concrete, which is a lightweight concrete consisting of cement, filler, water and a foaming agent. This study aims at the development of a cost-effective high-volume fly-ash foam-concrete insulation wall cladding for existing buildings using natural fiber like rice straw in different proportions. The paper reports the results of systematic studies on various mechanical, acoustic, thermal and durability properties of foam-concrete with and without replacement of cement by fly-ash. Fly-ash replaces 60 percent by weight of cement in foam-concrete. The water-solid ratio of 0.3, the filler ratio of 1:1 by weight, and the density of 1100 kg/㎥ (approx.) are fixed for all the mixes. Rice straw at 1%, 3% and 5% by weight of cement was added to improve the thermal and acoustic efficiency. From the investigations, it was inferred that the strength properties were increased with fly-ash replacement up to 1% rice straw addition. In furtherance, addition of rice straw and fly-ash resulted in improved acoustic and thermal properties.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.1C
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• pp.17-25
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• 2012

CLSM (Controlled Low Strength Material) using coal ash, which has the advantages of self-leveling, self-compacting, flowability, easy re-excavation, has been developed. In this study, CLSM additionally mixed with foaming agent for structural backfill material, aimed at lightness of materials, was developed called light-weight foamed CLSM. As the basic study of this material, to determine the optimum final mixing time and dilution ratio of existing light-weight foamed CLSM, flow, slurry unit weight and unconfined compressive strength test according to each impact factor were performed at the standard mix proportion. As the results of tests, CASE N (Final mixing time 4 min, dilution ratio 2%), CASE O (Final mixing time 3 min, foam agents ratio 3%, dilution ratio 2%) were satisfied with the standard of flow test (above 20cm), slurry unit weight test (12~15 $kN/m^3$) and unconfined compressive strength test (800 kPa~1200 kPa). These results will indicate the standard optimum final mixing time and dilution ratio of light-weight foamed CLSM for structural backfill.

• Korean Journal of Agricultural Science
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• v.23 no.1
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• pp.120-130
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• 1996

Concrete is the most commonly used structural materials, but in concrete construction, its self-weight represents a very large proportion of the total load on the structure, and there are clearly considerable advantages in reducing the density of concrete. This study was carried out to investigate the stress-strain properties of no-fines synthetic lightweight concrete with synthetic lightweight coarse aggregates. The used synthetic lightweight coarse aggregate were two types, one was expanded clay with grading 3~8mm, the other is pumice stone with grading 4.75~10mm. The results of this study were summarized as follows ; The static modulus of elasticity of the synthetic lightweight concrete was $1.8{\times}10^5kg/cm^2$ at type CE using the expanded clay and $1.6{\times}10^5kg/cm^2$ at type CL using the pumice stone. The dynamic modulus of elasticity was $1.9{\times}10^5kg/cm^2$(CE) and $2.0{\times}10^5kg/cm^2$(CL). The dynamic modulus of elasticity was 10~30% larger than that of the static modulus of elasticity. The load-time curves of synthetic lightweight concrete were shown approximately similar to each other type except for added foaming agent. The stress-strain curves in uniaxial compressive of synthetic lightweight concrete were similar to each other.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.6
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• pp.1775-1781
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• 2008

The effects of the type of curing agent on the swelling of the natural rubber(NR) sponge applicable to the self-sealing layer of a helicopter fuel tank were investigated. The curing systems employed were peroxide and mixed ones of sulfur and peroxide. The NR compounds were prepared in a kneader and a roll-mill. The compounds were partially cured in a press at high pressure and subsequently cured fully with expansion in another press at atmospheric pressure. The apparent density of the NR sponge was measured and the cell structure was observed with scanning electron microscopy. The swelling experiments were performed at room temperature using toluene, iso-octane, and an aircraft fuel as a solvent. More rapid volume swelling of the NR sponge cured by peroxide was achieved than cured by sulfur and peroxide with similar amount of curing agent added in rubber compounds. The apparent density and cell structure of the sponge were extremely sensitive to the amount of peroxide, which influences again the swelling behavior of the NR sponge. It is important to control properly two reactions of decomposition of foaming agent and crosslinking of NR in the mold to obtain rapid swelling of the NR sponge on contact of the fuel.