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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal DOI :
The Polymer Society of Korea
Editor in Chief :
Volume & Issues
Volume 29, Issue 6 - Dec 2005
Volume 29, Issue 5 - Sep 2005
Volume 29, Issue 4 - Jul 2005
Volume 29, Issue 3 - May 2005
Volume 29, Issue 2 - Mar 2005
Volume 29, Issue 1 - Jan 2005
Selecting the target year
Morphology Formation and Application of Interpenetrating Polymer Network (IPN) Materials
Kim, Sung-Chul ;
Polymer Korea, volume 29, issue 1, 2005, Pages 1~7
Interpenetrating polymer network (PN) is a mixture of network polymers. The characteristics of IPN material is the control of morphology during the IPN synthesis. By controlling the relative kinetics of chemical reaction (as well as gellation) and phase separation, the morphology of IPN can be controlled to obtain materials with nano-scale domain and also the co-continuous phase. Other important advantage is the fact that the morphology is permanent due to the presence of the physical interlocking between the networks. The combination of hydrophilic polyurethane and hydrophobic polystyrene in IPN form provides enhanced blood compatibility due to the co-existence of the hydrophilic and hydrophobic domains in nano-scale on the surface. The reaction temperature, reaction pressure and the degree of crosslinking were varied during the IPN synthesis and the morphology and blood compatibility of the resulting IPN materials were studied.
Preparation and Thermal Properties of Polystyrene Nanoparticles Containing Phase Change Materials as Thermal Storage Medium
Park, Soo-Jin ; Kim, Ki-Seok ; Hong, Sung-Kwon ;
Polymer Korea, volume 29, issue 1, 2005, Pages 8~13
Polystyrene (PS) particles containing the phase change material (PCM) were synthesized by miniemulsion polymerization. The polymer particles prepared with different parameters were investigated in terms of average particle size, particle distribution, and latent heat storage of encapsulated paraffin wax (PW) as PCM. The morphology and particle features of PS particles were analyzed by scanning electron microscope and particle size analyzer, respectively. As a result, the diameters of PS particles were adjusted with manufacturing conditions. The stable and spherical PS particles of nanosize were obtained by miniemulsion polymerization, which could be attributed to the prevention of Ostwald ripening by cosurfactant. Thermal properties of PS particle containing PCM were studied by differential scanning calorimetry. From DSC freeze-thaw cycle, PCM coated with PS exhibited the thermal energy storage and release behaviors, and the latent heat was found to be a maximum 145 J/g. It was noted that PS particles containing PCM showed a good potential as a thermal energy storage medium.
Study on the Frictional Properties of Nylons Synthesized by Varying Catalyst Content
Chung, Dae-Won ; Kang, Suk-Choon ;
Polymer Korea, volume 29, issue 1, 2005, Pages 14~18
Nylons were synthesized by anionic polymerization of
--caprolactam while varying the content of catalyst. Polymerization rates, molecular weights, mechanical properities and frictional properties of the nylons were investigated. As the ratio of catalyst to initiator was increased up to 1.0%, the polymerization rate, conversion and molecular weight were found to increase, and mechanical properties except impact strength were improved. Frictional properties were affected mainly by tensile strength and hardness. According to the study on the friction coefficient, product of stress (P) and velocity (V), PV limit, and abrasive wear rate, nylon synthesized at 1.0% of the ratio of catalyst to initiator showed the best performance for sliding machine elements.
Effects of Blend Composition and Compatibilizer on the Mechanical Properties of Polypropylene/Acrylonitrile-Butadiene-Styrene Blends
Park, Jung-Hoon ; Sung, Yu-Taek ; Kim, Woo-Nyon ; Hong, John-Hee ; Hong, Byeong-Kwon ; Yoo, Tae-Wook ; Yoon, Ho-Gyu ;
Polymer Korea, volume 29, issue 1, 2005, Pages 19~24
Polymer blends containing polypropylene (PP) with compatibilizers were prepared using twin screw extruder. Physical properties were investigated using universal test machine (UTM) and Izod impact tester. In the PP/acrylonitrilebutadiene-styrene (ABS) blends, mechanical strength was increased with the addition of PP-g-styrene acryloritrile (PP-g-SAN) compatibilizer, and the ductility was increased with the addition of ethylene-ethyl acrylate-maleic anhydride (E-EAMAH-g-SAN) compatibilizer. For the PP/ABS/ polycarbonate (PC)/Nylon-6,6 blends, impact strength was increased with the addition of ethylene glycidylmethacrylate (E-GMA compatibilizer) up to 0.5 phr. In the case of the PP/ABS/PC/Nylon-6,6/poly(methyl methacrylate) (PMMA)/poly(oxymethylene) (POM)/poly(vinyl acetate) (PVC)/poly(butylene terephthalate) (PBT) blends, mechanical properties were increased by the complex compatibilizing effects of PP-g-SAN, E-EA-MAH-g-SAN and E-GMA, respectively.
Photochromic Properties of Cellulose Derivatives Having Spirobenzopyran Group
Xiangdan, Li ; Kim, Eun-Kyoung ; Lee, Myong-Hoon ;
Polymer Korea, volume 29, issue 1, 2005, Pages 25~31
Cellulose acetate derivatives containing 6-(p-hexyloxyphenyl)carbonyl spirobenzopyran (CA-COSP) were prepared from base-catalyzed etherification of cellulose acetate, and their physical and photochromic properties were characterized. The degree of substitution of COSP was calculated from the amount of residual hydroxyl groups in cellulose acetate measured by the
-NMR and UV spectrometric data. It was ranging from 0.87 to 45.5% depending on the reaction condition. UV/vis spectrometry of the resulting CA-COSP revealed that the polymer shows a reversible color change by changing its color from colorless to blue upon UV irradiation forming a merocyanine structure, and returning back again to colorless spiropyran structure by visible light or by heat. The rate of color change was faster in solution than in the film. In the more polar solvent, the more stable was the resulting merocyanine, and the slower was the rate of reverse reaction to spiropyran. Compared to COSP blended with cellulose acetate, in which a phase separation was observed for samples containing more than 0.9 wt% of COSP, up to 48 wt% of COSP could be blended in CA-COSP without phase separation.
Effect of Ozone Treatment of Carbon Nanotube on PTC/NTC Behaviors of High-Density Polyethylene Matrix Composites
Park, Soo-Jin ; Seok, Su-Ja ; Lee, Jae-Rock ; Hong, Sung-Kwon ;
Polymer Korea, volume 29, issue 1, 2005, Pages 32~35
In this paper, the carbon nanotubes (CNTs) were ozonized and the positive temperature coefficient (PTC) behaviors of CNTs-filled high-density polyethylene (HDPE) conductive composites were studied. The results of element analysis (EA) and FT-IR indicate that the oxygen-containing functional groups on the CNTs surfaces, such as O-H, C-O, and C＝O groups, were increased with the ozonization. Electrical resistivities of the CNTs/HDPE composites were measured by using a digital multimeter. The resistivity of the composites was increased abruptly near the crystalline melting temperature of the HDPE used as matrix, which could be attributed to the destruction of conductive network by the thermal expansion of HDPE. And, the PTC intensity of the CNTs/HDPE composites was increased with the increase of the ozone treatment time. It was probably due to the growing of maximum volume resistivity of the composites induced by the increased oxygen-containing functional groups in the CNTs surfaces.
Synthesis and Characterization of Poly(ethylene glycol) Grafted Polysuccinimide
Lim, Nak-Hyun ; Lee, Ha-Young ; Kim, Moon-Suk ; Khang, Gil-Son ; Lee, Hai-Bang ; Cho, Sun-Hang ;
Polymer Korea, volume 29, issue 1, 2005, Pages 36~40
Poly(amino acid) derivatives have been widely investigated as a drug carrier in drug delivery system. Particularly,polysuccinimide (PSI) is one of the most promising drug carriers since it possesses suitable physicochemical characteristics for development of macromolecular prodrugs, due to biocompatibility and biodegradability. In this study, we deal with the synthesis of polyaspartamide having various functional groups such as methoxy-poly(ethylene glycol) (MPEG) via ring closing of PSI. PSI was synthesized by polyonensation polymerization of spartic acid. The variety of average molecular weight was confirmed with reacion time and catalyst content to observe the optimum condition of synthesis. MPEG, hydrophilic chain, was bonded to fabricate polymeric micell composed of hydrophilic and hydrophobic polymer. All materials were characterized by 1H-NMR, FT-IR and GPC. In addition, the formation of nanoparticle micelle as drug carrier were also examined. Micelle size was measured by ELS and AFM. The functionalized polysparamide formed nanoparticle micelle whose size ranged from 90 to 130 nm. In conclusion, we prepared polyaspartamide functionalized with PEG examined the possibility as drug carriers.
The Kinetics of Transesterification between Dimethylterephthalate and 1,3-Propanediol
Na, Sang-Kuwon ; Kong, Byeong-Gi ; Choi, Chang-Yong ; Kim, Jung-Gyu ; Hong, Wan-Hae ; Nah, Jae-Woon ;
Polymer Korea, volume 29, issue 1, 2005, Pages 41~47
The transesterification of dimethyl terephthalate (DMT) with 1,3-propanediol (PDO) was investigated in the presence of catalyst, titanium (IV) butoxide (TBO), at 175~190
. The degree of transesterification reaction was measured by the output of methanol which was distilled from the reactor. The amount of methanol increased as the reaction temperature, molar ratio and catalyst concentration increased. The observed overall rate of the transesterification was third order; first order with respect to DMT, PDO, and the concentration of catalyst, respectively. Using calculated rate constants, the activation energy for transesterification was 26.93 kcal/mole. The melting temperature of bis(2-hydroxytrimethyl) terephthalate (BHTMT) was 85.2
and heat of fusion 141.3 J/g.
Severity Factors Affecting Tire Wear
Lee, Jae-Woo ; Chung, Chang-Bock ; Choi, In-Chang ;
Polymer Korea, volume 29, issue 1, 2005, Pages 48~53
Tire wear is one of the factors that most drivers have concerned and is closely related to the tire life. It is very difficult to predict tire wear because the factors affecting tire wear seem to be very comlicated. Tire wear test should be performed at real conditions for the evaluation of tire wear. In this study, we analyze tire wear according to the severities of test courses by using the dedicated test method, more severe than real driving conditions. In order to simplify the factors affecting tire wear, we define roads’ driving severities to be driving severity numbers, DSNs which are obtained by measuring the lateral accelerations of test courses. And we compared tire wear rates and profiles with DSNs. These test results can provide the tire design guide to meet tire wear performance.
Degradation Behavior of Poly[(R)-3-hydroxybutyrate] by Using Single Crystals and Monolayers as Model Systems
Kim, Seong-Soo ; Lee, Won-Ki ; Ahn, Yong-Sik ;
Polymer Korea, volume 29, issue 1, 2005, Pages 54~58
The hydrolytic behavior of microbial poly[(R)-3-hydroxybutyrate]](P(3HB)) has been studied by using two model systems, Langmuir monolayer and solution-grown single crystals (SCs), for elucidating the mechanism for both alkaline and enzymatic degradations. An initial degradation of SCs of P(3HB) leads to breakup lamellae parallel to their short axis (b-axis). Similarly, ridge formation on the lamellar surface appears along the b-axis at lower quenching temperature than melting temperature. Both results support that the lamellar crystals contain less-ordered and more thermally sensitive regions along the b-axis. Although the enzymatic hydrolysis of P(3HB) monolayers was similar to its alkaline one, the enzymatic degradation of P(3HB) monolayers occurred at higher constant surface pressure than the alkaline degradation. This behavior might be attributed to the size of enzymes which is much larger than that of alkaline ions; that is, the enzymes need larger contact area with monolayers to be activated.
Kinetics on the Synthesis of Poly(caprolactone diol) and Aliphatic Lsocyanate by FTIR Spectroscopy
Kang, Suk-Hwan ; Yang, Yun-Kyu ; Kwak, Noh-Seok ; Kang, Yun-Uk ; Hwang, Taek-Sung ;
Polymer Korea, volume 29, issue 1, 2005, Pages 59~63
Kinetic study of a reaction between poly(caprolactone diol) and aliphatic isocyanate was investigated by FTIR spectroscopy. The reaction rate was obtained from analyzing the absorbance change of NCO peak (2265
) in series IR spectra. In the results, the overall reaction between PCL and isocyanate conformed to the simple second-order law, and the rate constant increases with increasing reaction temperature. The activation energies obtained from the evaluation of kinetic data were 25.4∼30.9 kJ/mol for hexamethylene diisocyanate and 16.8∼22.1 kJ/mol for cyclohexylmethane diisocyanate, respectively.
Product Distribution Characteristics of High-Impact Polystyrene Depolymerization by Pyrolysis
Lee, Bong-Hee ; Yu, Hong-Jeong ; Kim, Dae-Su ;
Polymer Korea, volume 29, issue 1, 2005, Pages 64~68
To recycle collected high-impact polystyrene (HIPS) wastes as liquid fuel, depolymerization characteristics of HIPS by pyrolysis was studied. The effects of temperature and time on the pyrolysis of HIPS were investigated. The depolymerization temperature and activation energy of HIPS pyrolysis increased with increasing heating rate. In general, conversion and liquid yield gradually increased with pyrolysis temperature and pyrolysis time. Each liquid product formed during pyrolysis was classified into gasoline, kerosene, light oil and heavy oil according to the distillation temperature based on the petroleum product quality standard of Korea Petroleum Quality Inspection Institute. As a result, the amount of liquid products produced during HIPS pyrolysis was in the order of gasoline》heavy oil〉kerosene〉light oil. Especially 51
6 wt% of HIPS treated was obtained as gasoline.
Preparation and In Vitro Release of DNA-Loaded Poly(D,L-lactic-co-glycolic acid) Microspheres
Son, Hye-Jung ; Kim, Jin-Seok ;
Polymer Korea, volume 29, issue 1, 2005, Pages 69~73
To overcome the main disadvantages of non-viral gene delivery systems such as repeated administration due to the low transfection efficiency, poly(D,L-lactide-co-glycolide) was applied to encapsulate pDNA in its microsphere formulation. Free pDNA or various ratios (w/w) of chitosan/pDNA complexes was used for encapsulation, with the resulting encapsulation efficiency of 44%, 5%, and 8% for free pDNA, 0.7:1 and 1:1 ratios, respectively. Scanning electron micrographs of poly(D,L-lactic-co-glycolic acid) (PLGA) microspheres encapsulating pDNA or chitosan-condensed pDNA revealed a smooth spherical shape immediately after microsphere preparation and a collapsed porous shape in 41 days due to the degradation of PLGA. In vitro release profile showed that the 0.7:1 (w/w) ratio formulation exerted 47% release in 26 days, whereas free pDNA or 1:1 (w/w) ratio formulation did only 15% or 32%, respectively.
Synthesis of Bead Type lon Exchangers and Selective Adsorption Properties of Carbonyl Compounds in Cigarette Mainstream Smoke
Lee, John-Tae ; Park, Jin-Won ; Rhee, Moon-Soo ; Hwang, Keon-Joong ; Hwang, Taek-Sung ;
Polymer Korea, volume 29, issue 1, 2005, Pages 74~80
To use the filter materials for reduction of carbonyl compounds in cigarette mainstream smoke, the bead type cation and anion exchangers were synthesized by the suspension polymerization of GMA and DVB followed by the subsequent functionalization with sodium sulfite and diethylamine, respectively. FT-IR/ATR was used to characterize functionalized copolymer formation by sulfonation and amination, and the morphology change of ion exchangers according to the adsorption of cigarette mainstream smoke were observed by SEM. Ion exchange capacity, functionalization yield and adsorption properties of carbonyl compounds in cigarette mainstream smoke were investigated. The highest functionalization yields and ion exchange capacity were obtained at 5 wt% DVB content in co-monomer. The adsorption amount of carbonyl compounds in cigarette mainstream smoke of anion exchanger was higher than that of cation exchanger because of its electron delocalization in carbonyl group. The adsorption efficiency was increased in the presence of moisture. This results indicated that the anion exchanger was applicable for cigarette filter material because of its large ion exchange capacity and rapid ion exchange reaction.
Effects of Physical Properties on Waterborne Polyurethane with Poly(tetramethylene glycol) (PTMG) and Polycaprolactone (PCL) Contents
Yang, Yun-Kyu ; Kwak, Noh-Seok ; Hwang, Taek-Sung ;
Polymer Korea, volume 29, issue 1, 2005, Pages 81~86
In this study, waterborne polyurethanes were synthesized with poly(tetramethylene glycol) (PTMG), polycarprolactone PCL), dimethylol propionic acid (DMPA) and different molar ratio of chain extender. Particle size, polydispersity, thermal and mechanical properties of waterborne polyurethane were investigated. The particle size of waterborne polyurethane was in the range of 5∼200 nm and decreased with increasing the amounts of PCL and chain extender. Glass transition temperatures (
) were in the range of -70∼-45
and increased with as PCL and chian extender (ED) contents increased. The
of polyurethane prepared from the mixture showed similar trends as compared with those of in the same values of synthetic polyurethane using PTMG or PCL, respectively. Also, mechanical properties of mixed polyols (PTMG and PCL) were lower than those of PTMG and PCL, respectively.
Real-Time XRD Analysis of Polystyrene/Clay Nanocomposites by In-Situ Polymerization
Kim, Jang-Yup ; Hwang, Seok-Ho ; Hong, Yoo-Seok ; Huh, Wan-Soo ; Lee, Sang-Won ;
Polymer Korea, volume 29, issue 1, 2005, Pages 87~90
In this study, we have examined the exfoliation behavior of layered clay during in-situ polymeriztion with styrene by using real-time XRD analysis. The 4C1 beam line at the Pohang Accelerator Laboratory (PAL) was used for this study. Different exfoliation behaviors have been shown to depend on the cation exchange capacity (CEC) of clay and the chemical structure of organic modifiers. For 10A-MMT and 15A-MMT having high CEC, no peak shifts were observed on real-time XRD analysis during polymerization. However, 2
for 25A-MMT and VDAC-MMT, each having low CEC’s as well as aromatic benzene moieties and vinyl groups, respectively, decreased as polymerization time increased.
Study on the Chemical and Radiation Crosslinking of Poly(vinyl alcohol) Hydrogels for an Improvement of Heat Resistance
Park, Kyoung-Ran ; Nho, Young-Chang ;
Polymer Korea, volume 29, issue 1, 2005, Pages 91~95
The PVA hydrogels were prepared by the chemical and irradiation method to improve the heat resistance of these hydrogels at the high temperature. The physical properties such as the gel content, the degree of swelling and the gel strength for the synthesized hydrogels were examined. Gel content increased as the chemical reaction time and the irradiation dose increased, and gel content of the hydrogels were higher when the two-steps of chemical and irradiation method were used rather than only the chemical method. Gel strength increased as the chemical reaction time increased, and as the irradiation dose decreased. The hydrogels prepared by the chemical reaction for 5 hours and the two-steps had the heat resistance at the high temperature.
Investigation into the Thermal Stability of Fluoropolymer Coating for Heat-Resistant Application
Cho, Hey-Jin ; Ryu, Ju-Hwan ; Byun, Doo-Jin ; Choi, Kil-Yeong ;
Polymer Korea, volume 29, issue 1, 2005, Pages 96~101
Fluoropolymer of PTFE and PFA etc. is a heat resistance polymeric material that it is known as that maximum continuous use temperature reaches for 260
. It was observed that these polymers had the enough thermal stability so enough that it was kept by thermal aging of 280
/7 weeks too in this study. However, such thermal stability means that bulk material property is kept such as mechanical strength, melting point and initial pyrolysis temperature etc. If these polymers are evaluate by coating property such as surface contact angle, surface morphology, surface scratch, thing that heat resistance is not enough was confirmed in this study. Thermal aging of flouropolymer coating was achieved by gear aging oven that the exchange rate of air was controlled, and the analysis results were indicating serious damage of surface morphology and adhesive strength on metal substrate.
Esthetic Properties of Photoinitiated Polymeric Dental Restorative Nanocomposites
Kim, Oh-Young ; Han, Sang-Hyuk ; Kim, Chang-Keun ;
Polymer Korea, volume 29, issue 1, 2005, Pages 102~105
Photoinitiated polymeric dental restorative nanocomposites (PDRNC) were designed to be useful for the variety of dental restoration. Hybrid-filler composed of barium silicate (avg. dia.:1
) and nano-sized silica (avg. dia: 40 and 7 nm) was adopted as a filler system. To improve the interfacial behavior with the resin matrix of bisphenol A glycerolate methacrylate/triethyleneglycol dimethacrylate (60/40 wt%), the surface of the filler was hydrophobically treated with a silane coupling agent. A visible light system of camphorquinone photo-initiator and 2-(dimethylamino)ethyl methacrylate photo-accelerator was utilized to activate the PDRNC. Esthetic properties of PDRNC was investigated by measuring the Hunter L, a, b values and it was discovered that PDRNC produced in this work showed excellent esthetic properties with an increase in 7 nm nanofiller content.