• Proceedings of the Korean Fiber Society Conference
• /
• 2003.10a
• /
• pp.59-60
• /
• 2003

The undrawn monofilament of poly (trimethylene terephthalate) (PTT) was obtained by melt-spinning. After being annealed at 40 C it was analyzed by the measurements of DSC, DMA, WAXD and ATR FT-IR. Tg of PTT fiber after annealing for more than 96 hours was 20 C higher than that before annealing as determined by the DSC and DMA measurements. The WAXD analysis showed very weak diffraction peaks at 2$\theta$=17$^{\circ}$ and 2$\theta$=24$^{\circ}$ for the annealing time of more than 96 hours. The ATR FT-IR measurements made clear the conformational change of methylene chains of PTT glycol residue from random to gauche-gauche conformation.

• Fibers and Polymers
• /
• v.6 no.3
• /
• pp.200-205
• /
• 2005

Celite powder surface-modified with cationic surfactant was used to make polyethylene (PE) specialty film that can be contrasted with ordinary film in having high odor storing capacity and long odor lasting period. Mechanical properties of the films were sacrificed as more celite particles were included, whether celite surface was modified or not. The film with CTAS-modified celite showed the best odor storing and lasting properties for five different flavors of odor, three artificial and two natural ones, among the kinds of films developed. Comparisons among the different films are made, together with brief discussion about the reason for differences in odor lasting period and possible application to packaging industry.

• Textile Coloration and Finishing
• /
• v.14 no.3
• /
• pp.34-43
• /
• 2002

Abstract-Many studies have been carried out to improve the dyeability of anionic dyes onto cellulosic fibers. Modification of control using cationic compounds has been most widely used. In this study, an effort was made to cationize cotton fabrics using cellulose-reactive allylamine polymer, namely triazinyl N,N'-dimethyl-N,N'-diallyl ammonium chloride in the previous work. The results showed that the dye-uptake of treated cotton fabrics with acid dyes and reactive dyes markedly increased in the various dyeing conditions. In addition, the dyeing rate of cationized cotton was also faster than that of untreated counterpart. Furthermore, the antimicrobial property was also investigated to determine the effects of cationization.

• Proceedings of the Polymer Society of Korea Conference
• /
• 2006.10a
• /
• pp.65-66
• /
• 2006

[ $TiO_2$ ] single crystalline nanorods are prepared from electrospun fibers which are composed of nanofibrils with an island-in-a-sea morphology. The mechanical pressure produces each fibril into nanorods which are converted to anatase single crystals after calcinations. HRTEM shows that the (001) plane is growing along the longitudinal direction of the rod. In this work, the nanorod electrode provides the efficient photocurrent generation in a quasi-solid state dye-sensitized solar cells (DSSCs) using highly viscous PVDF-HFP based gel electrolytes. The overall converision efficiency of the $TiO_2$ nanorods shows 6.2 % under $100\;mW/cm^2$ (AM 1.5G) illumination.

• Fibers and Polymers
• /
• v.7 no.1
• /
• pp.73-78
• /
• 2006

The ability to absorb liquid and the dust removal performance are important factors for wiping cloths used to remove contaminants. We have developed a method that can determine the contaminant removal performance of wiping cloths. In the gravimetric method, experimental errors are unavoidable because the contaminant plate is much heavier than the contaminant material. However, we used image analysis to reduce the experimental errors, and did not use the heavy contaminant plate. The correlation coefficient between the image. analysis and the gravimetric methods was very high, at R=0.97, with a significance level of 95%. From the correlation analysis and empirical data, the image analysis method is a useful tool for measuring wiping efficiency. The wiping efficiency measured using image analysis has a close relationship to the wiping speed, viscosity of the contaminant, and wiping pressure, at the significance level of 95%.

• Fibers and Polymers
• /
• v.5 no.2
• /
• pp.95-104
• /
• 2004

A series of superabsorbents based on acrylic acid (AA), sodium acrylate, 2-acrylamido-2-methylpropane sulphonic acid, N,N'-methylene bis-acrylamide (MBA) were prepared by inverse suspension polymerization. These hydrogels were further crosslinked on the surface with polyethylene glycol-600 (PEG-600). The water absorbency or swelling behaviors for these xerogels in water and 0.9% saline solutions, both under free condition and under load were investigated. Absorption characteristics of these hydrogels were found to depend on nature and concentration of crosslinker in the system. It was also found that the saline absorption was significantly improved as the incorporation of AMPS in the polymer was increased. The surface crosslinking introduced in the polymers was found to improve the absorption under load characteristics without lowering the free water absorption capacities of the polymer to a considerable extent.

• Fibers and Polymers
• /
• v.5 no.2
• /
• pp.145-150
• /
• 2004

Blends of poly(phenylene sulfide) (PPS) and polyethylene, either linear low density polyethylene (LLDPE) or metallocene-catalyzed polyethylene (MPE), that were prepared by melt blending, were investigated. From the rheological properties as determined by capillary rheometry, the melt viscosity of both PPS/LLDPE and PPS/MPE blends was low when PE was in dispersed phase, but high melt viscosity was observed for both blends with PPS in dispersed phase. Significant differences depending on the composition were found in the mechanical properties such as percent elongation at break and notched Izod impact strength. In addition, dispersed phase morphology of the blends was analyzed by a scanning electron microscope (SEM), together with brief discussion about the difference between them.

• Carbon letters
• /
• v.15 no.3
• /
• pp.162-170
• /
• 2014

Pitch is an attractive raw material for carbon fiber precursors due to its low cost stemming from its availability as a residue of coking and petroleum processes. Ford Motor Company reported a carbon fiber target price of $11.0/kg by using a fast cycle-time manufacturing method with carbon fiber in an inexpensive format, allowing for an average retail price of gasoline of $3.58/gallon. They also recommended the use of carbon fiber with strength of 1700 MPa, modulus of 170 GPa, and 1.5% elongation. This study introduced a ca. $5.5{\mu}m$ carbon fiber with 2000 MPa tensile strength obtained from a precursor through simple distillation of petroleum residue. Petroleum pitch based carbon nanofibers prepared via electrospinning were characterized and potential applications were introduced on the basis of their large specific surface area and relatively high electrical conductivity.

• Fibers and Polymers
• /
• v.2 no.2
• /
• pp.58-63
• /
• 2001

Silk fibroin (SF) was dissolved in calcium chloride/ethanol/water mixture(1/2/8 in mole ratio) at $70^{\circ}C$ for 4h. The dissolved silk fibroin was regenerated by casting the dialyzed solution into films. The films were treated with 50% aqueous solution of methanol for different times, and their antithrombogenicity was evaluated by in vivo tests. In vivo blood tests were made by a method of peripheral vein indwelling suture. It was found that the silk fibroin had a good antithrombogenicity and an absorbability even though the polymer showed foreign body reaction. Finally, the blood compatibilty of silk fibroin films which were subjected to structural change by the methoanl treatment, was examined in connection with their interfacial surface energy, and a correlation between these properties was found to be present.

• Fibers and Polymers
• /
• v.6 no.4
• /
• pp.289-296
• /
• 2005

Biodegradable nanocomposites were prepared by mixing a polymer resin and layered silicates by the melt intercalation method. Internal structure of the nanocomposite was characterized by using the small angle X-ray scattering (SAXS) and transmission electron microscope (TEM). Nanocomposites having exfoliated and intercalated structures were obtained by employing two different organically modified nanoclays. Rheological properties in shear and extensional flows and biodegradability of nanocomposites were measured. In shear flow, shear thinning behavior and increased storage modulus were observed as the clay loading increased. In extensional flow, strain hardening behavior was observed in well dispersed system. Nanocomposites with the exfoliated structure had better biodegradability than nanocomposites with the intercalated structure or pure polymer.