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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal DOI :
The Polymer Society of Korea
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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
Preparation of Gradient Polymer Surface and Their Pluripotent Biomedical Applications
Lee, Hai-Bang ; Kim, Moon-Suk ; Cho, Young-Ho ; Khang, Gil-Son ; Lee, Jin-Ho ;
Polymer Korea, volume 29, issue 5, 2005, Pages 423~432
Over last three decades, various biomaterials has been developed and applied in the biomedical market. The practical utilization of biomaterials depends on the study about an appropriate physical and biological response of biomaterials. The modification of biomaterials using various surface treatment methods has recently become an interesting topic in the field of surface engineering. A padient surface is the surface on which a gradually varying chemical composition exists along its length. A large number of research groups have been focused on the preparation of gradient surfaces. Such gradient surface is of particular interest for basic and applied studies of the interactions between biological species and surfaces since the effect of a selected property like wettability or chemical composition can be examined in a single experiment on one surface. The present review focuses on the preparation and characterization of various gradient surfaces, and their interactions with biological species.
Synthesis and Water Repellency of Polymers with Fluorinated Alkyl Group and Isocyanate Group
Baek Chang-Hoon ; Kong Jong-Yun ; Hyun Seok-Hee ; Lim Yong-Jin ; Kim Woo-Sik ;
Polymer Korea, volume 29, issue 5, 2005, Pages 433~439
The copolymers were prepared by the emulsion copolymerization of fluoroalky lacrylate-stearylacrylate-m-isopropenyl-
-dimethylbenzyl isocyanate (TMI) in order to obtain water repellent polymers. The respective copolymerization rates of the three monomers considerably depended upon the use of the nonionic emulsifier and the nonionic-cationic mixed emusifier, and the optimum conditions were obtained. The particle sizes of the copolymers were in the range of 105 to 222nm. The particle sizes of the copolymers prepared by the use of the mixed emulsifiers were smaller than those of the copolymers prepared by the use of the nonionic emulsifier. The reactions of both TMI-N-methyl acetamide and TMI-cellobiose did not take place. However, the reaction of TMI-n-butylamine occurred. The water contact angles before and after washing three times for nylon and poly(ethylene terephthalate) (PET) fabrics coated with the copolymer prepared by the use of mixed emulsifier were about
Therefore, the copolymer showed good durable repellency for nylon and PET.
Preparation of Amino Acid Copolymers/water-insoluble Drug Nanoparticles: Polymer Properties and Processing Variables
Yoo Ji Youn ; Lee Soo-Jeong ; Ahn Cheol-Hee ; Choi Ji-Yeun ; Lee Jonghwi ;
Polymer Korea, volume 29, issue 5, 2005, Pages 440~444
An increase in the surface area of drugs by reducing particle sizes from microns to nanometers has been known as an efficient method to improve the bioavailability of water-insoluble drugs. To prevent drug nanoparticles from aggregation during the processes of drug formulation, a limited number of pharmaceutical inactive ingredients such as hydroxypropyl cellulose has been employed as stabilizers or dispersants. In this study, copolymers of hydrophilic and hydrophobic amino acids were synthesized by the ring opening polymerization of their N-carboxyanhydride monomers and evaluated as novel candidates to stabilize the nanoparticles of a water insoluble drug, naproxen. Naproxen nanoparticles stabilized by synthesized amino acid copolymers were successfully prepared in the size of
in 60 min by a wet comminution process. Particle size analysis showed that the effective stabilization performance of copolymers required the hydrophobic moiety content to be higher than
. However, the molecular weight and morphology of copolymers was not the critical parameters in determining the particle size reduction. Their particle size was found to be stable up to 14 days without significant aggregation.
Synthesis and Characteristics of Hyaluronic Acid Bead Crosslinked by 1,3-Butadiene diepoxide
Kwon, Ji-Young ; Cheong, Seong-Ihl ;
Polymer Korea, volume 29, issue 5, 2005, Pages 445~450
Hyaluronic acid-based beads were prepared in order to develop a biomedical material for augumentation. Hyaluronic acid was crosslinked by 1,3-butadiene diepoxide in a suspension state maintained by rapid mixing of soybeen oil and hyaluronic acid solution. The particle size, surface area and swelling ratio were measured to investigate the physical properties of the synthesized beads and the bead surface was examined by scanning electron microscopy. The beads were formed in the range of
concentration of crosslinking agent, which showed monodisperse size distribution. Both BET surface area and swelling ratio decreased as the concentration of either hyaluronic acid or crosslinking agent increased, and crosslinking temperature decreased. Bead size could be effectively controlled by mixing speed without affecting other physical property.
Synthesis and Characterization of Heat Resistant Organophilic Layered Silicate Modified with Oligo(amic acid)s Having Alkyl Side Chains and Their Nanocomposites
Han Ji Yun ; Won Jong Chan ; Lee Jae Heung ; Suh Kyung-Do ; Kim Yong Seok ;
Polymer Korea, volume 29, issue 5, 2005, Pages 451~456
In the field of designing of nano-fillers of polyimide nanocomposites, the two strategic points are the heat-resistance and compatibility with polyimide, a matrix polymer. In this study, we designed oligo(amic acid) having alkyl side chains and terminal amine groups to satisfy previous requirements and studied the modification of surface of layered silicates. Oligo(amic acid)s were prepared by the reaction of diamine monomers and PMDA and their molecular weight was controlled in about 2000g/mol. After that, acidification and ion exchange reaction led to the high-temperature organophilic layered silicate (OLS). XRD pauerns of OLS showed the more increased gallery spacing by
than that of the pristine layered silicate and the initial decomposition temperatures of OLS were in above
. The polyimide nanocomposite films based on heat resistant OLS showed that the OLSs were well dispersed through the matrix and their CTEs showed a decrease of
compared with pristine polyimide films.
Effects of Isocyanate Index and Aging on the Physical Properties of Polyurethane Foams
Kwon Hyun ; Kim Sang-Bum ; Kim Youn Cheol ;
Polymer Korea, volume 29, issue 5, 2005, Pages 457~462
Polyurethane foams (PUFs) were prepared from polymeric 4,4'-diphenylmethane diisocyanate (PMDI), mixed polyol with OH value of 480, silicone surfactant, three catalysts, and hydrofluorocarbon(HFC) as blowing agent. Balance (PC-8), gelling (33LV), and trimerization (TMR-2) catalysts were used. The effect of the catalysts on the physical properties of PUF with increase of isocyanate (NCO) index and aging time was investigated. The cell size of the PUF with PC-8 and 33LV slightly increased with an increase in NCO index from 100 to 170 but compressive strength did not change significantly. In case of trimerization catalyst, the compressive strength of PUF increased from 8.75 to 1
and the cell size decreased with an increase in NCO index. The compressive strength of the PUF with 33LV increased from 9.21 to
with an increase in aging time. However, there was no detectable change in the compressive strength of PUF with TMR-2. A possible interpretation of the results includes an additional cross-link reaction of non-reacted MDI and FTIR spectrum illustrated the change of NCO peak.
The Effect of Crosslinking on the Actuation of Electroactive IPMC Prepared with Fluoroalkyl Methacrylate/Acrylic Acid/HEMA Copolymer
Jeong, Han-Mo ; La, Young-Soo ;
Polymer Korea, volume 29, issue 5, 2005, Pages 463~467
In order to enhance the actuation force of ionic polymer-metal composite (IPMC) made with the acrylic copolymer of fluoroalkyl methacryate, acrylic acie, and 2-hydroxyethyl methacrylate(HEMA), the hydroxy group of HEMA was corsslinked with 1,3-diethoxy-1,1,3,3-tetramethyldisiloxane. The water uptake was reduced and the mechanical strengths and the actuation force of the membrane was improved by crosslinking. However, current and deformation responses of IPMC were decreased by crosslinking.
The Release of Albumin from PLGA and PCL Wafers Containing Natural and Synthetic Additives for Protein Delivery
Hyun Hoon ; Lee Jae Ho ; Seo Kwang Su ; Kim Moon Suk ; Rhee Jhon M. ; Lee Hai Bang ; Khang Gilson ;
Polymer Korea, volume 29, issue 5, 2005, Pages 468~474
PLGA and PCL copolymers initiated by carbitol as drug carriers were synthesized by ring-opening polymerization of L-lactide (LA), glycolide (GA), and
. Implantable wafers were simply fabricated by direct compression method after physical mixing of copolymers and bovine serum albumin-fluorescein isothiocyanate (BSA-FITC) as a model protein drug. The release amounts of BSA-FITC from wafers were determined by fluorescence intensity using the fluorescence spectrophotometer. Also, the release behavior of BSA-FITC on wafers was controlled by adding the additives such as collagen, small intestinal submucosa (SIS), poly(vinyl pyrrolidone) (PVP), and poly(thylene glycol) (PEG). The wafer prepared by PLGA and PCL exhibited slow release within
for 30 days. But, those prepared by a variety of additives exhibited the controlled BSA release patterns with a dependence on the additive contents. furthermore, the wafers containing natural materials such as collagen and SIS showed more zero-order release profile than that with synthetic materials such as PVP and PEG. It was confirmed that the release of BSA from implantable wafers could be easily controlled by adding natural additives.
Processability Enhancement in Melt Processing of Poly(ethylene naphthalate)
Kim Hyogap ; Kang Ho-Jong ;
Polymer Korea, volume 29, issue 5, 2005, Pages 475~480
The lowering of melt viscosity has been investigated to achieve the processability enhancement in poly(ethylene naphthalate) (PEN) melt processing by the reactive melt blending with poly(ethylene terephthalate) (PET) and introducing lubricant as well. CaST lubricant resulted in the lowering of PEN melt viscosity but noticeable mechanical property drop was found in PEN with more than
of lubricant due to the acceleration of thermal degradation by excess lubricant. PEN/PET (90/10) blend has less melt viscosity than PEN and transesterification between two polymers caused the additional viscosity depression. further viscosity lowering was found in PEN/PET blend with CaST since CaST is acting as the catalyst of transesterification as well as a lubricant in PEN/PET blend.
A Study on Thermal and Mechanical Properties of Vapor Grown Carbon Nanofibers-Reinforced Epoxy Matrix Composites
Park Soo-Jin ; Lee Eun-Jung ; Lee Jea-Rock ;
Polymer Korea, volume 29, issue 5, 2005, Pages 481~485
In this work, the thermal and mechanical properties of vapor grown carbon nanofibers (VGCNFs)-reinforced difunctional epoxy (EP) composites were investigated in the presence of the 0, 0.1, 0.5, 1.0, and
VGCNFs. The thermal properties of the VGCNFs/EP composites were studied by thermo-mechanical analysis (TMA) and dynamic mechanical analysis (DMA). The mechanical properties of the VGCNFs/EP composites were also examined by universal testing machine (UTM), falling impact test, and the friction and wear tests. From experimental results, the thermal and mechanical properties of the VGCNFs/EP composites were improved with increasing the VGCNFs contents. This was due to the increase of crosslinking structure of the composites, resulting in improving the mechanical interlockings between VGCNFs and epoxy resins in the present composite system.
Synthesis and Characterization of Non-Conjugated Polymers with Hole-Conductor and Red-Emitter in Side-Chain
Shim, Na-Young ; Lee, Hoo-Sung ;
Polymer Korea, volume 29, issue 5, 2005, Pages 486~492
Into a no-conjugated polymer chain we have introduced side chains with a styrene-linked triphenylamine segment as a
donor, styrene-]inked aminobenzaldehyde segment as a tunable reactive -CHO group, and PM (4-(dicyanomethylene)-2-(tert-butyl)-4H-pyran) moiety as a
acceptor for red emitting materials. The thermal stability and the optical properties of the statistical copolymers have been studied. All the polymers were electrochemically active and showed electroluminescent emission at around 700nm. The EL device of P5-PM based on the sturcture of
showed a maximum brightness of
with an external quantum efficiency of
. It was possible to enhance the external quantum efficiency by balancing the charge recombination. A red-emitting polymer with high external quantum efficiency was developed by incorporating bifunctionality
Syntheses and Characterization of PBO Precursors Containing Dimethylphenoxy and/or MPEG Pendant Groups
Yoon Doo-Soo ; Choi Jae-Kon ; Jo Byung-Wook ;
Polymer Korea, volume 29, issue 5, 2005, Pages 493~500
Polyhydroxyamides(PHAs) having poly(ethylene glycol)methyl ether (MPEG) and/or dimethylphenoxy pendant groups were synthesized by solution polycondensation at low temperature. The inherent viscosities of the PHAs measured at
in DMAC or DMAc/LiCl solution were in the range of
. This precursor polymers were studied by FT-IR,
, DSC, and TGA. Solubility of the precursors with higher MPEG unit was increased, especially the polymer having MPEG
was soluble or partially soluble in ethanol, methanol, and water as well as aprotic solvents, but the PBOs were nearly insoluble in a variety of solvents. PHAs were converted to polybenzoxazoles (PBOs) by thermal cyclization reaction with heat of endotherm. In case of the precursors having MPEG nit, the precursor polymers with a higher
were fully cyclized at a lower temperature than one with a lower
Effects of SIS Sponge and Bone Marrow-Derived Stem Cells on the Osteogenic Differentiation for Tissue Engineered Bone
Park Ki Suk ; Jin Chae Moon ; Yun Sun Jung ; Hong Keum Duck ; Kim Soon Hee ; Kim Moon Suk ; Rhee John M. ; Khang Gilson ; Lee Hai Bang ;
Polymer Korea, volume 29, issue 5, 2005, Pages 501~507
Small intestinal submucosa (SIS) had been widely used as a biomaterial without immune rejection responses. SIS sponges prepared by crosslinking with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC). SIS powders dissolved in
acetic acid aqueous solution for 48hrs and freeze-dried. EDC solution (
: ethanol = 5 : 95) as a crosslink agent was used in concentration of 100mM. In vitro, rat-BMSCs seeded in SIS sponges and induced the osteogenesis for 28 days. We have characterized the osteogenic potential of rat-BMSCs in SIS sponges by alkaline phosphatase activity(ALP), n assay, SEM and RT-PCR for osteogenic phenotype. In SEM, all morphology of SIS sponges was regular and showed interconnected pore structure. By RT-PCR analysis, we observed type I collagen expression. These results demonstrate osteogenic differentiation of rat-BMSCs. In conclusion, we confirmed that the morphology of surface, cross-section, and side of SIS sponges were highly porous with good interconnections between each pores, which can support the surface of cell growth, proliferation, and differentiation. This result indicates that SIS sponge is useful for osteogenesis of BMSCs.
Thermal Degradation Behavior and Reliability Analysis of Plastic Materials for Household Electric Appliances
Im, Chang-Gyu ; Kim, Jun-Young ; Kim, Seong-Hun ;
Polymer Korea, volume 29, issue 5, 2005, Pages 508~517
The thermal degradation behavior and reliability analysis were investigated using dynamic thermogravimetric analysis (TGA) and accelerated degradation test (ADT) to characterize the dynamic parameters related to thermal degradation of plastic meterials for household electric appliances. In addition, the weathering of the plastic were performed by ADT using Xenon uc, and the color difference of the samples after ADT were measured with Color Eye 3010 specoophotometer. he activation energy for thermal degradation of the samples increased with increasing the rate of weight loss. The Kim-Park method was found to be more effective analysis in describing thermal degradation of plastic meterials. Plastic materials were very sensitive to ultra-violet rays in faster degradation.
Preparation and Properties of Biodegradable Hydrogels from Poly(2-hydroxyethyl aspartamide) and HMDI
Kim Jeong Hoon ; Sim Sang Jun ; Lee Dong Hyun ; Kim Dukjoon ; Lee Youngkwan ; Kim Ji-Heung ;
Polymer Korea, volume 29, issue 5, 2005, Pages 518~521
Biodegradable polymers and hydrogels have been increasingly applied in a variety of biomedical applications including current drug delivery system and tissue engineering field.
(N-2-hydroxyethyl-DL-aspart-amide), PHEA. is one of poly(amino acids) with hydroxyethyl pendants, which is hewn to be biodegradable and potentially biocompatible. So that, the utilization and various chemical modifications of PHEA have been attempted for useful biomedical applications. In this wort chemical gels based on PHEA were prepared by crosslinking with diisocyanate compound in DMF in the presence of catalyst. Here, the PHEA was prepared from polysuccinimde, the thermal polycondensation product of aspartic acid, via ring-opening reaction with ethanolamine. The preparation of gels and their swelling behavior, depending on the different medium and pH, were investigated. Also the morphology by SEM and simple hydrolytic degradation were observed.