Suisan, South Korea
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Jeong E.,Chungnam National University | Lim J.W.,Hyochang Corporation | Seo K.-W.,Hyochang Corporation | Lee Y.-S.,Chungnam National University
Journal of Industrial and Engineering Chemistry | Year: 2011

In this study, the effects of physicochemical treatments of illite on thermo-mechanical properties and thermal stability of the hybrid illite/epoxy composites were investigated. Illite was chemically modified with octadecylamine (ODA), to become more organophilic and also physically modified by wet ball-milling process, so that the illite dispersion in the epoxy matrix and interfacial adhesion between illite and epoxy resin could be improved. Then, as-received illite and physically and/or chemically modified illites were mixed with epoxy separately to produce hybrid illite/epoxy composites and their thermo-mechanical properties and thermal stability were investigated. Chemical modification was confirmed with FTIR and the aforementioned properties of illite/epoxy composites were characterized with SEM, DMA, and TGA. IR results show that ODA modification of illite was successful and thermo-mechanical properties were enhanced with illite introduction to the epoxy resin, especially when physically and chemically modified illite was added, showing about 100% increase in storage and loss modulus, compared to the pure epoxy. However, thermal stability was not enhanced by forming the illite/epoxy composites, because the composites prepared in this study were intercalated and flocculated illite/epoxy microcomposites. © 2010 The Korean Society of Industrial and Engineering Chemistry.

Lim J.W.,Chungnam National University | Jeong E.,Chungnam National University | Seo K.,Hyochang Corporation | Lee Y.-S.,Chungnam National University
Applied Chemistry for Engineering | Year: 2011

In this study, illite was size-reduced using a wet-ball-milling treatment to improve its dispersion. Changes in illite particle size, size distribution, and dispersion characteristics after varying the treatment period were investigated. And the dispersion and dispersion stability of illite solution after 2 h wet ball milling treatment with different pH conditions were also evaluated. The illite particle size significantly decreased as the treatment time increased and the size reduction effect of wet ball milling deteriorated above 2 h treatment time. In addition, illite particle size was more evenly distributed as the treatment time increased. X-ray diffraction (XRD) analysis showed that no crystal structural changes of illite were induced, but the characteristic peak of illite the weaker due to the size reduction and exfoliation, as the treatment time increased. Zeta potential analysis showed that the illite dispersion improved, as the treatment time increased. The illite wet-ball-mill treated at pH 2 had the lowest dispersion stability. Illite dispersion and dispersion stability increased as pH increased, due to the increase in surface ionization. Hence, the results showed that as the treatment time increased, the illite particle size decreased, and dispersion and dispersion stability improved due to the increase in surface energy and repulsion force between particles.

Kim J.,Chungnam National University | Im J.S.,Chungnam National University | Seo K.-W.,Hyochang Corporation | Lee Y.-S.,Chungnam National University
Polymer (Korea) | Year: 2013

In this work, the thermal, antibiotic properties and far-infrared emissivity of fluorinated illite embedded polypropylene non-woven fibers (f-illite/PP fibers) were investigated in the presence of 0, 1, 3, 5 and 7 wt% illite powders. The thermal properties of f-illite/PP fibers were studied by thermogravimetric analysis (TGA). Their antibiotic properties were examined by Staphylococcus aureus and Klebsiella pneumoniae test. Their far-infrared emissivity was also investigated by Fourier transform infrared spectroscopy. From the experimental results, thermal, antibiotic properties and far-infrared emissivity of f-illite/PP fibers were improved by increasing fluorinated illite contents and the property values of 5 wt% f-illite/PP fibers were increased remarkably by about 10.3, 41.2 and 9.8% respectively in comparison with PP non-woven fibers having no fluorinated illite additive. This result was interpreted as the development of interfacial adhesion force between the polymer chains due to the fluorination of illite power.

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