• Korea-Australia Rheology Journal
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• v.13 no.2
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• pp.61-65
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• 2001

Thermoplastic nanocomposites based on the copolymers of polypropylene (PP)-polystyrene (PS) and organically modified montmorillonite (org-MMT) were produced by using power ultrasonic wave in an intensive mixer. Owing to the unique action of the ultrasonic wave, free radicals of styrene monomers and macroradicals of PP were generated, by which copolymers of PP and PS were formed. Another important aspect of using ultrasonic wave during the mixing process was to enhance nano-scale dispersion of org-MMT by destructing the agglomerates of org-MMT in the polymer matrix. Optimum conditions for the in-situ copolymerization and melt intercalation were studied with various concentrations of styrene monomer, sonication time and different kinds of clay. It was found that a novel attempt carried out in this study yielded further improvement in the mechanical performance of the nanocomposites compared to those produced by the conventional melt mixing process.

• Proceedings of the Korean Society of Rheology Conference
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• 2003.05a
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• pp.167-170
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• 2003

No Abstract, See Full Text

• Proceedings of the KAIS Fall Conference
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• 2004.11a
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• pp.296-298
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• 2004

본 연구에서는 압출성형에서 Nylon6 를 기재로 멜라민계 난연제를 사용하여 난연성 및 물성평가를 비교, 분석하였다. 멜라민계 난연제를 선택한 이유는 탈할로겐화 추세에 일조를 하며 연기가 적고, 생분해를 하는 물질이기 때문에 큰 장점이 있다. 또한 새로운 제품 및 적용범위를 발굴하기가 상대적으로 용이하다는 장점이 있기 때문에 멜라민계 난연제를 선택하였다. 난연 Test는 UL-94 측정방법을 이용하였고 물성평가는 UTM 측정기기로 인장강도, 연신율, 굴곡강도, 굴곡탄성율 측정하였다. 또 충격강도 시험기로 충격강도를 측정하였고, 물성평가 경우에는 난연제로 인한 물성저하를 최소화 하기위해 Nano-clay 를 첨가하여 비교하였다. 연구결과는 난연 Test 경우 난연제의 함량이 $5wt\%$ 이상이면 V0급으로 나왔고 물성평가에서는 Nanoclay를 첨가한 실험이 물성저하를 대처할 수 있을 정도의 결과로 보여 진다.

• Elastomers and Composites
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• v.49 no.1
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• pp.43-52
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• 2014

The effect of nanoclay (Cloisite 20A) on the self-adhesion behavior of uncured brominated-isobutylene-isoprene rubber (BIIR) has been studied. The dispersion state of nanoclay into the rubber matrix was examined by SEM, TEM and XRD analysis. The thermal degradation behavior of the filled and unfilled samples was examined by TGA and improvement in the thermal stability of the nanocomposites occurred based on the weight loss (%) measurements. Also, addition of nanoclay enhanced the cohesive strength of the material by reinforcement action thereby reducing the degree of molecular diffusion across the interface of butyl rubber. However, the average depth of penetration of the inter-diffused chains was still adequate to form entanglement on either side of the interface, and thus offered greater resistance to peeling, resulting in high tack strength measurements. The improvement in tack strength was only achieved at critical nanoclay loading above 8 phr. Contact angle measurement was also made to examine the surface characteristics. There was no significant interfacial property change by employing the nanoclay.

• Polymer(Korea)
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• v.31 no.6
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• pp.518-525
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• 2007

The thermomechanical properties and morphologies of nanocomposite fibers of poly(ethylene terephthalate)(PET) incorporating thermally stable organoclays are compared. Dodecyltriphenyl-phosphonium-mica($C_{12}PPh-Mica$) and 1-hexadecane benzimidazole-mica ($C_{16}BIMD-Mica$) were used as reinforcing fillers in the fabrication of PET hybrid fibers. Dispersions of organoclays with PET were studied by using the in-situ polymerization method at various organoclay contents to produce nano-scale composites. The thermo-mechanical properties and morphologies of the PET hybrid fibers were determined using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), wide angle X-ray diffraction (XRD), electron microscopy (SEM and TEM), and a universal tensile machine (UTM). Transmission electron microscopy (TEM) micrographs show that some of the clay layers are dispersed homogeneously within the polymer matrix on the nano-scale, although some clay particles are agglomerated. We also found that the addition of only a small amount of organoclay is enough to improve the thermal stabilities and mechanical properties of the PET nanocomposite fibers. Even polymers with low organoclay content (<5 wt%) were found to exhibit much higher thermo-mechanical values than pure PET fibers.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.2
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• pp.287-292
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• 2014

The objectives of this study were to examine the effects of red clay-processed nano-materials (RCPM) on the quality characteristics of eel (Anguilla japonica). Both eels treated with RCPM and control were farm-raised under identical environments and were commercially processed. General components, texture, nutrients, antioxidant activities, and sensory analysis were performed. RCPM-treated eels showed significantly higher DPPH radical scavenging activities and FRAP values than the of control, indicating higher antioxidant activities of eels raised by RCPM. The amounts of niacin and tocopherol in RCPM-treated eels were higher than those of the control. For analysis of freeze-thaw stability, RCPM-treated eels showed more stable texture over freeze-thaw three treatment cycles. Descriptive panelists perceived eels raised by RCPM to be less oily than the control. Overall, RCPM exhibited positive effects on the quality of farm-raised eels. Therefore, RCPM would be of benefit to produce high value-added eels of premium quality.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.22 no.3
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• pp.49-58
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• 2016

Corrugated board provides packaging for most diverse industries with a share of over 50%, due to the numerous advantages they offer a good protection of the products. In other hand corrugated board fails in environmental conditions, indicating that relative humidity or temperature is higher. These effects directly damage the product packaged. To overcome on this problem recently corrugated boards produced with functional material, "functional corrugated boards," have become more available in the current market. A number of commercialized forms of functional material are coated or composited products with inorganic materials, for example "Nano clay" as representative. However, although the use of functional materials is increasing in corrugated boards, the several concerns such as over cost, environmental friendly materials, recycling, and toxicity affect consumer perceptions and acceptance. In the past, number of researcher focused on process of box compression and the utility of box compression testing etc., best of our knowledge there is no review paper which focus on the functional corrugated boards used in food packaging applications. This paper aims to review the availability of functional corrugated boards in the current market, past research studies on functional material and present the current status of functional corrugated boards in leading countries.

• Macromolecular Research
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• v.14 no.2
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• pp.132-139
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• 2006

The dispersion of organoclay in ethylene propylene diene terpolymer (EPDM) matrix was correlated with the rheological and swelling properties of nanocomposites. X-ray diffraction pattern (XRD) and transmission electron microscopic (TEM) analysis exhibited the disordered-intercalated structure of EPDM/organoclay nanocomposite. The extent of the disordered phase increased with increasing organoclay content up to a limiting value of 3 wt% after which equilibrium tended towards intercalation. The dispersion effect of organoclay in EPDM matrix was clarified by the physicochemical properties like rheological response and swelling thermodynamics in toluene. The increase in viscoelastic properties of EPDM nanocomposite with increasing organoclay content up to 3 wt%, followed by a subsequent decrease up to 4 wt%, was correlated in terms of the disordered and ordered states of the dispersed nano-clay sheets. Swelling measurements revealed that the change in entropy of the swelling increased with the increase in disorder level but decreased with the increase in intercalation level of organoclay in the disordered-intercalated nanocomposite. The increase in solvent uptake was comparable with the free volume in EPDM matrix upon inclusion of silicate particles, whereas the inhibition in solvent uptake for higher organoclay loading was described by bridging flocculation.

• Journal of the Mineralogical Society of Korea
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• v.29 no.2
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• pp.73-78
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• 2016

The oxidation states of structural Fe in clay minerals often reflect the paleo-redox conditions of the depositional environments. It is inevitable to utilize the high resolution of transmission electron microscopy (TEM) to investigate the mechanism of mineral transformation at nano-scale. The applications of TEM- electron energy loss spectroscopy (EELS) for quantification of $Fe(III)/{\Sigma}Fe$ from the K-nontronite formation associated with structural Fe(III) reduction in nontronite under deep subseafloor environment were demonstrated. In particular, quantification of the changes in Fe-oxidation state at nanoscale is essential to understand the mechanisms of minerals formation. The procedure of EELS acquisition, quantitative determination of Fe-oxidation states, and advantages of EELS techniques were discussed.

• Advanced Composite Materials
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• v.16 no.4
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• pp.269-282
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• 2007

Fully biodegradable high strength composites or 'advanced green composites' were fabricated using yearly renewable soy protein based resins and high strength liquid crystalline cellulose fibers. For comparison, E-glass and aramid ($Kevlar^{(R)}$) fiber reinforced composites were also prepared using the same modified soy protein resins. The modification of soy protein included forming an interpenetrating network-like (IPN-like) resin with mechanical properties comparable to commonly used epoxy resins. The IPN-like soy protein based resin was further reinforced using nano-clay and microfibrillated cellulose. Fiber/resin interfacial shear strength was characterized using microbond method. Tensile and flexural properties of the composites were characterized as per ASTM standards. A comparison of the tensile and flexural properties of the high strength composites made using the three fibers is presented. The results suggest that these green composites have excellent mechanical properties and can be considered for use in primary structural applications. Although significant additional research is needed in this area, it is clear that advanced green composites will some day replace today's advanced composites made using petroleum based fibers and resins. At the end of their life, the fully sustainable 'advanced green composites' can be easily disposed of or composted without harming the environment, in fact, helping it.