Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal Basic Information
Journal DOI :
The Polymer Society of Korea
Editor in Chief :
Volume & Issues
Volume 38, Issue 6 - Nov 2014
Volume 38, Issue 5 - Sep 2014
Volume 38, Issue 4 - Jul 2014
Volume 38, Issue 3 - May 2014
Volume 38, Issue 2 - Mar 2014
Volume 38, Issue 1 - Jan 2014
Selecting the target year
Recent Applications of Polymeric Biomaterials and Stem Cells in Tissue Engineering and Regenerative Medicine
Lee, Sang Jin ; Yoo, James J. ; Atala, Anthony ;
Polymer Korea, volume 38, issue 2, 2014, Pages 113~128
DOI : 10.7317/pk.2014.38.2.113
Tissue engineering and regenerative medicine strategies could offer new hope for patients with serious tissue injuries or end-stage organ failure. Scientists are now applying the principles of cell transplantation, material science, and engineering to create biological substitutes that can restore and maintain normal function in diseased or injured tissues/organs. Specifically, creation of engineered tissue construct requires a polymeric biomaterial scaffold that serves as a cell carrier, which would provide structural support until native tissue forms in vivo. Even though the requirements for scaffolds may be different depending on the target applications, a general function of scaffolds that need to be fulfilled is biodegradability, biological and mechanical properties, and temporal structural integrity. The scaffold's internal architecture should also enhance the permeability of nutrients and neovascularization. In addition, the stem cell field is advancing, and new discoveries in tissue engineering and regenerative medicine will lead to new therapeutic strategies. Although use of stem cells is still in the research phase, some therapies arising from tissue engineering endeavors that make use of autologous adult cells have already entered the clinic. This review discusses these tissue engineering and regenerative medicine strategies for various tissues and organs.
Effects of Recycled PP Content on the Physical Properties of Wood/PP Composites
Ahn, Seong Ho ; Kim, Dae Su ;
Polymer Korea, volume 38, issue 2, 2014, Pages 129~137
DOI : 10.7317/pk.2014.38.2.129
In this study, the melt-mixing condition was optimized first to maximize the physical properties of a wood plastic composite (WPC) with recycled polypropylene (PP) and the effects of recycled PP content on the physical properties of the WPC were investigated. Mechanical properties of the WPC were measured by UTM and an izod impact tester and thermal properties were investigated by DSC, TGA and DMA. Fracture surfaces of the WPC were investigated by SEM. The optimized mixing condition of WPC with 50 wt% recycled PP of total PP was melt-mixing at
for 15 min at 60 rpm. With increasing the content of the recycled PP, the water absorption characteristics of the WPC increased and the thermal and mechanical properties decreased. However, the following was concluded from the analysis of all the physical properties; it was possible adding the recycled PP up to 50 wt% of total PP without a significant decrease in the performance of the WPC.
Preparation and Properties of Coating Materials of Polydimethylsiloxane with Acrylate Groups
Bak, Seung Woo ; Kang, Ho Jong ; Kang, Doo Whan ;
Polymer Korea, volume 38, issue 2, 2014, Pages 138~143
DOI : 10.7317/pk.2014.38.2.138
-Hydroxypropyl polydimethylsiloxane (HO-PDMS) was prepared by hydrosilylation of hydrogen terminated polydimethylsiloxane with allyl alcohol. Polydimethylsiloxane modified urethane with isocyanate group (PSU) was prepared from cyclic trimer of hexamethylenediisocyanate with HO-PDMS. PDMS modified urethane base resin with acrylic group (PSUA) was prepared from the urethane reaction of PSU with isocyanate group and 2-hydroxyethylmethacrylate. Their structures were characterized using FTIR and NMR. Coating materials were prepared by mixing PSUA, acrylic hardner, photo-initiator, and solvent and coated on PET film to obtain flexible and hard coating film by UV irradiation. Transparency of coating film was 89.7%, contact angle,
, and pencil hardness, 3H.
Comparison of Molding Characteristics for Multi-cavity Molding in Conventional Injection Molding and Injection Compression Molding
Lee, Dan Bi ; Nam, Yun Hyo ; Lyu, Min-Young ;
Polymer Korea, volume 38, issue 2, 2014, Pages 144~149
DOI : 10.7317/pk.2014.38.2.144
Large residual stresses are remained in the conventional injection molded products because of the high cavity pressure in packing phase during injection molding process. Conventional injection molding (CIM) invokes distribution of cavity pressure and it has a limitation to obtain product with uniform physical property. Multi-cavity conventional injection molding contains quality deviation among the cavities since flow imbalance occurs during filling phase. Injection compression molding (ICM) is adopted to overcome these limitations of CIM. In this study, molding characteristics of CIM and ICM have been investigated using multi-cavity injection mold. Researches were performed by both experiment and computer simulation through observations of birefringence for transparent resins, polycarbonate and polystyrene in CIM and ICM. As a result, low and uniform birefringence and mold shrinkage were showed in the specimens by ICM that could give a uniform cavity pressure. Deviation of physical property among the specimens in multi-cavity mold shown in CIM was significantly reduced in the specimens by ICM. Through this study it was concluded that the ICM in multi-cavity molding was valid for molding products with uniform property in an individual cavity and also reduced property deviation among the cavities.
Fabrication and Characterization of PCL/TiO
Nanoparticle 3D Scaffold
Kim, Jung-Ho ; Lee, Ok Joo ; Sheikh, Faheem A. ; Ju, Hyung Woo ; Moon, Bo Mi ; Park, Hyun Jung ; Park, Chan Hum ;
Polymer Korea, volume 38, issue 2, 2014, Pages 150~155
DOI : 10.7317/pk.2014.38.2.150
Polycaprolactone (PCL) is a synthetic biodegradable polymer with excellent mechanical properties.
(titanium dioxide) has a hydrophilic, high density and excellent biocompatibility. In this work, we produced three-dimensional porous scaffolds with PCL and
nanoparticles using a salt-leaching method. Physical properties of the scaffolds were analyzed by FE-SEM, FTIR, TGA and compressive strength. Interestingly, the addition of
nanoparticles decreased the water absorption and swelling ratio of the porous scaffolds. However, the compressive strength was increased by
. CCK-8 assay, which is generally used for the analysis of cell growth, shows that
nanoparticles have no cytotoxicity. Taken together, we suggest that the PLC/
-scaffold can be used for biomedical applications.
Inflammatory Responses to Hydroxyapatite/Poly(lactic-co-glycolic acid) Scaffolds with Variation of Compositions
Jang, Ji Eun ; Kim, Hye Min ; Kim, Hyeongseok ; Jeon, Dae Yeon ; Park, Chan Hum ; Kwon, Soon Yong ; Chung, Jin Wha ; Khang, Gilson ;
Polymer Korea, volume 38, issue 2, 2014, Pages 156~163
DOI : 10.7317/pk.2014.38.2.156
Hydroxyapatite has osteoconductivity, biocompatibility and noninflammatory, and it has been used clinically as artificial bone. In this study, we prepared hydroxyapatite/poly(lactic-co-glycolic acid) (PLGA) scaffolds using 0, 10, 20, 40 and 60 wt% of hydroxyapatite. We analyzed compressive strength, SEM analysis and FTIR for mechanical property of 3D hydroxyapatite/PLGA scaffolds. For biocompatibility tests, cell proliferation and viability were measured via MTT assay and SEM. We analyzed RT-PCR, FACS, histology (H&E, ED-1) for anti-inflammatory effect. This study showed that hydroxyapatite hybrid scaffolds have low inflammatory reaction compared with the PLGA. This result has a potential for the application of artificial bone graft material.
Comparison between Poly(lactic-co-glycolic acid) Films Contained Natural Polymers on Adhesion and Proliferation of Schwann Cells
Ko, Hyun Ah ; Jang, Ji Eun ; Kim, Hyeongseok ; Park, Chan Hum ; Kwon, Soon Yong ; Chung, Jin Wha ; Khang, Gilson ;
Polymer Korea, volume 38, issue 2, 2014, Pages 164~170
DOI : 10.7317/pk.2014.38.2.164
This study was designed to find an appropriate biomaterial to proliferate Schwann cell (SC). Poly(lactic-co-glycolic acid) (PLGA) films mixed with demineralized bone particle (DBP), small intestine submucosa (SIS), and silk were fabricated by a solvent casting method. Analysis of MTT, SEM and RT-PCR were performed to confirm adhesion and proliferation of SC. Contact angle of films was assayed for hydrophilicity of films. We confirmed that PLGA/DBP 20% film showed higher hydrophilicity, promoted adhesion and proliferation of SC than other films. It was concluded that PLGA/DBP film can be applied for the scaffold biomaterials for the regeneration of central nerve system.
Cure Behavior and Chemorheology of Low Temperature Cure Epoxy Matrix Resin
Na, Hyo Yeol ; Yeom, Hyo Yeol ; Yoon, Byung Chul ; Lee, Seong Jae ;
Polymer Korea, volume 38, issue 2, 2014, Pages 171~179
DOI : 10.7317/pk.2014.38.2.171
Low temperature cure prepregs are being developed for use in the preparation of large-structured fiber-reinforced polymer (FRP) composites with good performance. Cure behavior and chemorheology of low temperature cure epoxy resin system, based on epoxy resin, curing agent, and accelerators, were investigated to provide a matrix resin suitable for the prepreg preparation. Characteristics of cure reaction were studied in both dynamic and isothermal conditions by means of differential scanning calorimetry and rheometry. The low temperature cure epoxy resin system suggested in this study as a matrix resin was curable at
for 3 h, and showed the gel times of 120 and 20 min at 80 and
, respectively. Thermal and mechanical properties of the cured sample were almost the same as high temperature cure counterparts.
Preparation and Characterization of Conducting Polymer Nanocomposites Including Graphene Oxide via In-situ Chemical Polymerization
Jeong, Yeonjun ; Moon, Byung-Chul ; Jang, Min-Chae ; Kim, Yangsoo ;
Polymer Korea, volume 38, issue 2, 2014, Pages 180~187
DOI : 10.7317/pk.2014.38.2.180
Nanocomposites including graphene oxide (GO) and conducting polymers (PPy, PANI and PEDOT) were prepared via an in-situ chemical polymerization process, and their characteristic properties depending upon the change of conducting polymer (CP) content were analyzed. A confirmation was made on not only the functional groups formed in GO but also the presence of CP existent in the nanocomposites. The molecular interaction between GO and poly(4-styrene sulfonic acid) (PSSA) or CP in the nanocomposites was proposed. With the increase of PEDOT content in the GOPSS/PEDOT nanocomposite, the estimated value of
regarding the Raman analysis of them was decreased and a major change of their Raman spectra characteristic peaks was observed. In the GO-PSS/PEDOT nanocomposite, PEDOT molecules made an exfoliation of GO-PSSA layers and thus they were intercalated among layers. Such a unique molecular morphology induced the highest electrical conductivity for the GO-PSS/PEDOT nanocomposite among three kinds of nanocomposites prepared in this study. It is also noted that the uniform morphology confirmed in this study helped a thermal stability improvement in the nanocomposite due to the presence of GO or GO-PSSA acting as a thermal barrier.
Electrical Characteristics Enhancement of Conjugated Polymer Thin Film Transistor by Using Dipping Method
Kim, Hye Su ; Na, Jin Yeong ; Park, Yeong Don ;
Polymer Korea, volume 38, issue 2, 2014, Pages 188~192
DOI : 10.7317/pk.2014.38.2.188
In this work, it is possible to simply improve the molecular ordering of a conjugated polymer thin film by dipping into poor solvent. The structural order, optical, and electrical properties of poly(3-hexylthiophene) (P3HT) films were profoundly influenced by dipping time and solubility of solvent. Especially the dipping time in methylene chloride was controlled to efficiently improve the molecular ordering of the P3HT. The correlation between the structural order and the electrical properties was used to optimize the dipping time in the appropriate solvent.
Investigation of Molding Characteristics in Injection Compression Molding According to Molding Conditions through Birefringence
Lee, Dan Bi ; Nam, Yun Hyo ; Lyu, Min-Young ;
Polymer Korea, volume 38, issue 2, 2014, Pages 193~198
DOI : 10.7317/pk.2014.38.2.193
Lens and DVD require high quality of optical property. Conventional injection molded products contain high residual stress and this invokes birefringence since high cavity pressure and high temperature variation are involved in a molding process. Thus these products are often molded by injection compression molding in order to minimize the residual stress through reducing cavity pressure and uniform cavity pressure. In this study, molding parameters affecting molding quality such as property uniformity in injection compression molding were investigated through experiment. Molding quality deviations among the cavities in multi-cavity mold were also studied. Transparent resins, PC and PS were used in this study. Compression gap, compression speed, compression force, and compression delay time for processing variables in injection compression molding were applied in experiment. Compression force, compression delay time, and compression gap significantly affected the optical property of product. The degree of influence of process variable on the product quality was different in different resins. This implies that the optimal operational conditions in injection compression molding existed for each resin according to flow property.
Preparation of Acrylic Pressure Sensitive Adhesives for Optical Applications and Their Adhesion Performance
Baek, Seung-Suk ; Jang, Se-Jung ; Lee, Jong-Hoon ; Kho, Dong-Han ; Lee, Sang-Hoon ; Hwang, Seok-Ho ;
Polymer Korea, volume 38, issue 2, 2014, Pages 199~204
DOI : 10.7317/pk.2014.38.2.199
To prepare acrylic pressure sensitive adhesives (PSAs), quaternary copolymer syrups were photopolymerized from 2-ethylhexyl acrylate and 2-hydroxyethyl acrylate as default constituents and isobornyl acrylate and tetrahydrofurfuryl acrylate (THFA) as variable constituents. After polymerization, 1,6-hexanediol diacrylate and photoinitiator were added and then crosslinked by UV-irradiation to prepare the PSAs. The characteristics of the syrup such as viscosity, molecular weight, and solid content were investigated. As increasing THFA contents, the relationship between molecular weight and solid content of the syrup was reciprocal. Also, the relationship between peel strength and surface energy of the PSAs showed the same tendency. All the PSA samples showed high transmittance (more than 92%), low haze (less than 1.0%) and low color-difference (less than 1.0).
Enhanced Hydrophilicity of Polyethersulfone Membrane by Various Surface Modification Methods
Park, So Jung ; Hwang, Jun Seok ; Choi, Won-Kil ; Lee, Hyung Keun ; Huh, Kang Moo ;
Polymer Korea, volume 38, issue 2, 2014, Pages 205~212
DOI : 10.7317/pk.2014.38.2.205
Polyethersulfone (PES) membranes were modified by various physico-chemical modification methods to enhance the surface hydrophilicity for application as a separation membrane to separate and collect water vapor from the flue gas. Homogeneous PES flat-sheet membranes were prepared and modified by acid treatment, blending and plasma treatment for hydrophilic surface modification. The surface characteristics of the modified PES membranes were evaluated by ATR-FTIR, XPS, SEM and contact angle measurements. No significant change in hydrophilicity was observed for the PES membranes modified by acid treatment with sulfuric acid or blending with various compositions of poloxamer as an amphiphilic PEO-PPO-PEO tri-block copolymer. On the other hand, Ar plasma treatment led to a significant increase in the hydrophilicity of the surface, depending on the plasma treatment time. As a result, the PES membrane could be the most efficiently surface-treated by applying the plasma treatment for enhancing their surface hydrophilicity.
Rheological Characteristics of Highly Concentrated Polymer Bonded Explosive Simulant: Wall Slip, Thixotropy, and Flow Instability
Lee, Sangmook ; Hong, In-Kwon ; Ahn, Youngjoon ; Lee, Jae Wook ;
Polymer Korea, volume 38, issue 2, 2014, Pages 213~219
DOI : 10.7317/pk.2014.38.2.213
The rheological characteristics of highly concentrated polymer bonded explosive simulant were studied. Hydroxyl terminated polybutadiene (HTPB) and polyethylene plastomer (Exact) were used as binders. Sugar and Dechlorane particles whose physical properties are similar to research department explosive (RDX) were used as fillers. When HTPB was used, diethyl hexyl adipate (DEHA or DOA) was used as a plasticizer together for some cases. Highly concentrated suspensions were mixed in a batch melt mixer (Rheomixer 600, Haake) and rheological properties were measured by plate-plate and capillary rheometers. Wall slip phenomena, thixotropy with shear hysteresis, and flow instability were investigated as shear rate and amount of fillers changed.
Understanding of Protein Adsorption Kinetics to Contact Lens Hydrogels
Kim, Hyun-Jae ; Kim, Mira ; Noh, Hyeran ;
Polymer Korea, volume 38, issue 2, 2014, Pages 220~224
DOI : 10.7317/pk.2014.38.2.220
Protein adsorption kinetics was studied with the amount of proteins adsorbed to contact lens hydrogels over time scales. Hydroxyethylmethacrylate (HEMA) and silicone hydrogels were dipped in protein solutions (albumin or IgG) and adsorption amounts were measured over time scales. The amount of protein adsorbed to both hydrogel types increased rapidly in 10 min, and remained consistently in 90 min. Decreasing interfacial energetics was taken slowly up to an hour in spite of rapid diffusion of protein molecules. This is due to the fact that water deprivation from three dimensional interphase initially formed by protein diffusion took over an hour. Interpretation of adsorption kinetics on contact lens hydrogels was discussed with understanding of relationship between surface energy and protein adsorption capacity.
Estimation of Rheological Properties of Highly Concentrated Polymer Bonded Explosive Simulant by Microstructure Analysis
Lee, Sangmook ; Hong, In-Kwon ; Lee, Jae Wook ; Shim, Jung Seob ;
Polymer Korea, volume 38, issue 2, 2014, Pages 225~231
DOI : 10.7317/pk.2014.38.2.225
The rheological properties of highly concentrated polymer bonded explosive simulant were studied by using poly(ethylene-co-vinyl acetate) with 30 and 60% vinyl acetate (VA) content as a binder, respectively. Calcium carbonate and Dechlorane, whose physical properties are similar to resarch department explosive (RDX)'s, were used as fillers. The suspensions were mixed in a batch melt mixer and it was possible to fill 75 v% at maximum. From dynamic mechanical analysis, Dechlorane showed higher interaction with binder resins than that with calcium carbonate fillers. The effects of microstructural change on the rheological properties of the suspensions were investigated by a plate-plate rheometer with constant shear rate and constant shear stress modes, respectively. The theoretical maximum packing fraction of EVA31/Dechlorane suspension obtained from Krieger-Dougherty equation was 70 v% and it was thought that 2000 Pa was proper shear stress condition for this melt processing.
Comparison of the Properties of Poly(lactic acid) Nanocomposites with Various Fillers: Organoclay, Functionalized Graphene, or Organoclay/Functionalized Graphene Complex
Kwon, Kidae ; Chang, Jin-Hae ;
Polymer Korea, volume 38, issue 2, 2014, Pages 232~239
DOI : 10.7317/pk.2014.38.2.232
Poly(lactic acid)(PLA) nanocomposites containing various nanofillers were synthesized using the solution intercalation method. Organically modified bentonite clay (NSE), octadecylamine-graphene oxide (ODA-GO), and an NSE/ODA-GO complex were utilized as nanofillers in the fabrication of PLA hybrid films. PLA hybrid films with varying nanofiller contents in the range of 0-10 wt% were examined and compared in terms of their thermomechanical properties, morphologies, and oxygen permeabilities. Transmission electron microscopy (TEM) confirmed that most of the NSE and ODA-GO nanofillers were dispersed homogeneously throughout the PLA matrix on the nanoscale, although some agglomerate NSE/ODA-GO complex particles were also formed. Among the three nanofillers for PLA hybrid films, the NSE/ODA-GO complex showed the best improvement in film thermal stability. In contrast, NSE and ODA-GO exhibited the best improvement in tensile mechanical properties and oxygen barrier properties of the PLA hybrid films, respectively.
Carbon Nanotubes Reinforced Poly(ethylene terephthalate) Nanocomposites
Choi, Soohee ; Jeong, Youngjin ;
Polymer Korea, volume 38, issue 2, 2014, Pages 240~249
DOI : 10.7317/pk.2014.38.2.240
Multi-walled carbon nanotube (MWNT) reinforced poly(ethylene terephthalate) (PET) composites are studied. To increase the interfacial interactions between PET and MWNTs, the MWNTs are functionalized with bishydroxy-ethylene-terephthalate (BHET). The functionalized MWNTs are melt blended into PET matrix using a twin screw extruder. The amount of MWNTs loaded in PET matrix ranges from 0.5 to 2.0 wt%. After compounding and spinning, the filaments are post-drawn and annealed. To verify the chemical modifications of carbon nanotubes, Raman,
NMR, XPS, TGA and FE-SEM are used. The nanocomposites are also analyzed with DSC, TGA, and UTM. These tests show that crystallization temperature and thermal degradation temperature increase due to the functionalized MWNTs. Also, tensile test shows that yield strength and toughness increase more than 30% with addition of only 1 wt% of MWNTs. These results show that the introduction of BHET onto the MWNTs is a very effective way in manufacturing MWNT/PET composite.
Electrical Resistivity and Mechanical Properties of Polypropylene Composites Containing Carbon Nanotubes and Stainless Steel Short Fibers
Jung, Jong Ki ; Park, Kihun ; Bang, Daesuk ; Oh, Myunghoon ; Kim, Bongseok ; Lee, Jong Keun ;
Polymer Korea, volume 38, issue 2, 2014, Pages 250~256
DOI : 10.7317/pk.2014.38.2.250
Polypropylene (PP) composites containing conductive multi-walled carbon nanotube (MWNT) and stainless steel short fiber (SSF) were manufactured using a twin screw extruder and characterized their surface resistivity and mechanical properties in this work. Surface resistivity measurements showed that the percolation threshold appeared at a lower MWNT loading when a small amount of SSF was added to PP/MWNT composites. Tensile modulus and strength of the composites increased but elongation-at-break decreased greatly compared to pure PP. Also, the effects of MWNT and SSF on storage modulus and tan
from dynamic mechanical analysis for the composites were examined, and the morphologies of fractured surface and the fillers were observed using a scanning electron microscope.
Spectroscopic Analysis on Michael Addition Reaction of Secondary Amino Groups on Silica Surface with 3-(Acryloyloxy)-2-hydroxypropyl Methacrylate
Lee, Sangmi ; Ha, Ki Ryong ;
Polymer Korea, volume 38, issue 2, 2014, Pages 257~264
DOI : 10.7317/pk.2014.38.2.257
In this study, we modified silica nanoparticles with bis[3-(trimethoxysilyl)propyl]ethylenediamine (BTPED) silane coupling agent, which has two secondary amino groups in a molecule, to introduce amino groups on the silica surface. After modification of silica, we used acrylate group containing 3-(acryloyloxy)-2-hydroxypropyl methacrylate (AHM) to introduce polymerizable methacrylate groups by Michael addition reaction. We used Fourier transform infrared spectroscopy (FTIR), elemental analysis (EA) and liquid and solid state cross polarization magic angle spinning (CP/MAS) nuclear magnetic resonance spectroscopy (NMR) to understand the reactions between N-H groups of BTPED modified silica surface and acrylate groups of AHM monomer. We confirmed Michael addition reaction between BTPED modified silica and AHM completed in 2 hr reaction time. We also found increased methacrylate group introduction with increase of mol ratio of the acrylate group of AHM to N-H group of BTPED modified silica by increase of C=O peak area of measured FTIR spectra. These results were also supported by EA and solid state