• Polymer(Korea)
• /
• v.31 no.5
• /
• pp.404-409
• /
• 2007

Polyurethane nanocomposites with inorganic nano fillers for the improvement thermal stability were prepared by the urethane reaction. Fire retardation properties of polyurethane nanocomposites were investigated by cone calorimeter and limited oxygen index (LOI). Maximum heat release rate of MMT-PU and $Bi_2O_3-PU$ polyurethane nanocomposites were decreased as 50% than polyurethane matrix and fire retardation properties of $MMT/Bi_2O_3-PU$ nanocomposte had the best improvement. The LOI of polyurethane nanocomposites also were improved as filling fillers in the nanocomposites over 20. The maximum heat release rates of MMT-PU, $Bi_2O_3-PU\;and\;MMT/Bi_2O_3-PU$ polyurethane nanocomposites were 764, 707, $635kW/m^2$, respectively and $MMT/Bi_2O_3-PU$ polyurethane nanocomposite exhibited the highest value of fire-retardant. We confirmed that polyurethane nanocomposites improved the fire retardation properties.

• Journal of Korean Society for Atmospheric Environment
• /
• v.19 no.6
• /
• pp.689-699
• /
• 2003

This study was to examine characteristics of treating toluene vapor, which gets to be problematic due to its harmful carcinogenicity and mass generation from various sources, through a biological treatment facility which is environment-friendly and adopts a high-efficient and low-cost clean technology. In order to identify whether Alnus Firma Fruit (AFF) can be used as a media for a bioreactor, its utility and basic operating factors, a study was conducted on pressure drop, supply of nutrient substances and retention time which are operating factors of a biofilter, and eliminating characteristics were compared between AFF and the conventional biological activatedcarbon (BAC) widely used as filter media. In the case of AFF, the initial microbial deposits was 2.3${\times}$10$^{7}$ CFU/g dry AFF, which represents the initial microbial density higher than the case of BAC showing 5.5${\times}$10$^{6}$ CFU/g dry BAC And it took about 2 weeks to acclimate until its eliminating rate got to be increased over 90%. As a result of comparing pressure loss taking place with the lapse of time between BAC and AFF, after 130 days passed at SV 25h$^{-1}$ , BAC showed that its eliminating efficiency had a tendency to drop greatly due to a great pressure loss (0.53\longrightarrow54.7 mm$H_2O$/m) caused by an excess of biomass as accumulated. On the other hand. AFF showed that the pressure drop was 0.53 mm$H_2O$/m, about 2 times as much as the initial pressure loss of 0.4 mm$H_2O$/m, which represents no great change in the pressure loss, and its eliminating efficiency was also shown to be continuously high. Therefore, when AFF was used as a filler for a biological treatment facility, a biological filter enabling improvement of the purifying efficiency to be promoted could be provided, and moreover, the pressure loss was so small that the filler replacement cycle or the back flushing cycle could be extended. So, even in terms of the operating cost, it was identified to be an economical filler When an inorganic material was used as a filler, the biofilters performance acted sensitively on whether nutrient substances were supplied or not. In the case of AFF with low adsorptivity, addition of ethyl-alcohol increased the solubility of toluene, and consequently, biodegradation got to be actively made by microbes, and thus, its eliminating rate could be increased. As the flow velocity and the inflow concentration got to be more increased, its eliminating rate got to be lower, and particularly, an increase in the flow velocity made its eliminating rate drop more greatly than an increase in the concentration.

• Proceedings of the Korean Fiber Society Conference
• /
• 2003.04a
• /
• pp.72-74
• /
• 2003

There has been extensive interest in the development of new nanocomposites. One kind of these systems is the hybrid based on organic polymers and inorganic minerals consisting of layered silicates. Some properties like stiffness, strength, barrier properties, thermal, and oxidative stability can be improved by the presence of the filler in the polymeric matrix[1]. It is reported that, in the nylon 6/clay nanocomposites, the modulus is increased, but impact strength and elongation at break are drastically decreased. (omitted)

• Proceedings of the KIEE Conference
• /
• 1988.11a
• /
• pp.179-182
• /
• 1988

This study is to investigate the adhesive strength of composite material's interface on the experimental methode of tree growth in the material. The results are as fellows 1) The irradiations of ultrasonic energy cause the mechanical vibration in the polymer composite materials of fluid state, so then bring about physical dispersion and heat form inorganic materials, being supposed to produce chemical crosslinking reaction, decreasing of voids between filler and matrix. 2) The characterics of the breakdown are increased by using coupling agent in the composite material. 3) As the intensity of ultrasonic energy and its irradiated time are larger, the tree inception and break-down voltages increase and the tree growing is slower. so we obtain that the interface adhesive force tan be strengthened by the irradiation of ultrasonic energy.

• Proceedings of the Polymer Society of Korea Conference
• /
• 2006.10a
• /
• pp.214-214
• /
• 2006

The huge amounts of wastes were produced nowadays. Among the solid waste stream, the waste plastic portion is about 20 % in weight, over 50 % in volume. But the most of waste plastics were incinerated or land filled. Only a bit of waste plastics were recycled and reused. On the view point of current energy crisis, this will be an extravagance of beneficial resource. So we should consider the waste plastics as a beneficial raw material. Also need to develop the field of reusing and recycling of post-consumed plastic. In this context, present paper describes the methodology for enhancing or improving the specific properties by way of using inorganic filler waste. Also develop the product from these post-consumed plastic.

• Proceedings of the KIEE Conference
• /
• 1998.07d
• /
• pp.1404-1406
• /
• 1998

The outdoor polymeric insulating materials such as silicone rubber, ethylene propylene diene monomer(EPDM), ethylene vinyl acetate(EVA) and epoxy are aged by various natural environment with the long-term performance in outdoor. In this paper, the effects of UV-ray on surface of silicone rubber were investigated by using the weather-Ometer. The accelerated aging stresses were simulated by UV radiation. high temperature and humidity as well as water spray. These the aging characteristics were examined through contact angle measurements, tracking resistance test, FT-IR and SEM/EDS analysis. the experimental results showed that tracking resistance decreases with increase in the UV-ray irradiation period. But the surface of silicone rubber kept hydrophobicity. It is found that the inorganic filler such as $Al(OH)_3$ improves tracking resistance and the $TiO_2$ is very effective in preventing degradation of silicone rubber surface from UV-ray.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2010.05a
• /
• pp.29-30
• /
• 2010

In this study, inorganic filler is used to improve the flexural strength of RC beam with GFRP instead of epoxy in wet condition. The flexural strength of RC beams was investigated by different condition with reinforcing frames and anchors dimension.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.4 no.2
• /
• pp.46-54
• /
• 1990

본 연구에서는 에폭시수지에 무기물충진제 SiO2를I첨가하여 제작된 시편의 주파수 및 온도변화에 따른 유전 완화특성을 연구하였다. 연구결과로 제작된 복합재료의 유전특성은 충진제의 함량증가에 따라 유전율은 상당히 증가하였으나 유전손실의 변화는 거의 없었다. 이와같은 사실을 포함한 모든 특성들은 충진제입자가 에폭시 매트릭스에 견고하게 결합되어 있다는 사실과 Maxwell-Wagner의 계면분극이론으로 잘 설명될 수 있다. 제작된 복합재료에 대한 특성의 검토에서 충진제(SiO2)의 입자는 에폭시 매트릭스와 견고하게 결합되어 있으며 충진제 첨가효과는 전반적으로 유전완화세기에는 별 영향을 미치지 못하나 계면분극효과에 의한 유전율을 증가시키는 효과가 있다.

• Journal of the Korean Society of Safety
• /
• v.21 no.1 s.73
• /
• pp.79-85
• /
• 2006

Olefinic compatibilized blend(R-PP/R-PE)/layered silicate composites have been prepared by melt intercalation technique directed from $Na^{+}$ montmorillonite(MMT) or organophilic montmorillonites while using magnesium hydroxide as flame retardant. Morphology and flammability properties were characterized by X-ray diffraction(XRD), transmission electron microscopy(TEM), scanning electron microscopy(SEM), thermogravimetry analysis(TGA), limiting oxygen index(LOI), UL94 test. It is found that the compatibilized blend/layered silicate(Cloisite 20A) nanocomposites have a mixed immiscible-intercalated structure and there is better intercalation when a compatibilizer is combined with the polymer and layered silicate to be melt blended. A very large increase in the LOI value was observed with hybrid filler addition and further enhancement in thermal stability and compatibility of blend was obtained for the compatibilized blend containing small amount of layered silicate.

• Journal of the Korean Society of Safety
• /
• v.21 no.1 s.73
• /
• pp.65-71
• /
• 2006

Flame retardancy and mechanical properties of polyolefinic mixed waste plastics/filler composites were investigated by using inorganic flame retardant(magnesium hydroxide) and PUB(polyurethane block) powder generated from cryogenic insulation process. All composites were obtained by extrusion and after compression molding. The effect of PUB powder on the properties of the composites was studied by tensile and izod impact test, morphology studies and flammability as LOI and UL94 vertical burning test and smoke density. The objective of this work is to obtain good mechanical properties from recycled PP composites with $Mg(OH)_{2}/PUB$ powder as fillers and optimum cost-performance balance, in addition to flame retardant characteristics.