• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2006.11a
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• pp.50-52
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• 2006

• Polymer(Korea)
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• v.36 no.2
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• pp.124-130
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• 2012

The uniform nanofibers of poly(L-lactide-$co$-${\varepsilon}$-caprolactone) (PLCL) with different contents of marine collagen (MC) were successfully prepared by electrospinning method. The effects of the major parameters in electrospinning process such as tip to target distance (TTD), voltage, nozzle size and flow rate on the average diameter of the electrospun nanofiber were investigated in generating composite nanofiber. The diameter and morphology of the nanofibers were confirmed by a scanning electron microscopy (SEM). Also, we measured a water contact angle to determine the surface wettability of the nanofibers. The average diameter of the nanofibers decreased as the value of TTD, MC contents, and voltages increased in comparison with that of pristine PLCL nanofiber. In contrast, the diameter of the nanofibers increased as the flow rate and inner diameter of nozzle increased in comparison with that of pristine PLCL. In addition, the hydrophilicity of the nanofiber and attachment of MG-63 cells on the sheets increased as incorporated collagen contents increased. Therefore, the marine collagen would be a potential material to enhance cellular interactivity of synthetic materials by mimicking the natural tissue.

• Macromolecular Research
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• v.8 no.4
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• pp.186-191
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• 2000

Clay-dispersed nanocomposites have been prepared by simple melt-mixing of three components, i.e. poly (styrene co-acrylonitrile) copolymer (SAN), poly ($\xi$-caprolactone ) (PCL), and an organophilic clay(Cloisite(R) 30A). In the present study, poly($\xi$-caprolactone) was added in the mixtures in order to facilitate the intercalation of SAN into the gallery of silicate layers, and the molecular weight effects of PCL on the dispersion of silicate layers were compared by changing the amount of added PCL. The degree of dispersion of 10-$\AA$-thick silicate layers of clay in the nanocomposites was investigated by using an X-ray diffractometer and a transmission electron microscope. It was found that PCL added in the mixture facilitate the intercalation of SAN copolymers into the galleries of silicate layers modified with an organic intercalant, resulting in the better dispersion of clay. It was, also, observed that the processing temperature influences the degree of clay dispersion.

• Polymer(Korea)
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• v.27 no.4
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• pp.285-292
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• 2003

The compatibility of poly(lactic acid)/poly($\varepsilon$-caprolactone) (PLA/PCL) blends as a function of blend composition was studied and triphenyl phosphite (TPP) was applied to PLA/PCL blends as a reactive compatibilizer. Especially the effect of compatibility on the crystallization behavior in both PLA/PCL blends and PLA/PCL blends with TPP was considered. PLA/PCL blends were immiscible based on thermal characteristics of PLA/PCL blends and the miscibility was depend upon the blend composition. The enhancement of compatibility was found in PLA/PCL blends with TPP depend upon its content. The rate of crystallization in PLA/PCL blend varied with blend composition. This was understood as the development of nucleation at the interface of PLA-PCL due to the immiscibility. TPP was acting as a compatibilizer as well as an agent for the acceleration of spherulite growth In PLA. As a result, the crystallization rate increased and the size of spherulite became larger than that of PLA/PCL blend without TPP.

• Polymer(Korea)
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• v.33 no.3
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• pp.248-253
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• 2009

Blend films based on the poly($\varepsilon$-caprolactone) (PCL) and amphiphilic biodegradable polymer, poly(ethylene glycol) grafted poly($\varepsilon$-caprolactone) (PCL-g- PEG), were prepared with different blend ratios in order to develop new biomedical material. PCL was the main component in the blend. The miscibility and characteristics of the blends were investigated. The crystallization temperature of the blend shifted to high temperatures with an increase of the graft copolymer contents when the homopolymer PCL was the main component of the blend. The PEG side chain in the blend affected the crystallization rate of the PCL crystals in the blend and alternating extinction bands were observed by optical microscopy. The protein adhesion behavior of the film was influenced by the water uptake of the film.

• Advanced Composite Materials
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• v.17 no.2
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• pp.157-166
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• 2008

In this study, multiwalled carbon nanotubes (MWCNTs) were compounded with the poly($\varepsilon$-caprolactone) (PCL) matrix at the solution state using chloroform. For homogeneous dispersion of MWCNTs in polymer matrix, oxygen-containing groups were introduced on the surface of MWCNTs. The mechanical properties of the PCL/MWCNTs composites were effectively increased due to the incorporation of MWCNTs. The composites were characterized using scanning electron microscopy in order to obtain information on the dispersion of MWCNT in the polymeric matrix. In case of 1.2 wt% of MWCNTs in the matrix, strength and modulus of the composite increased by 12.1% and 164.3%, respectively. In addition, the dispersion of MWCNTs in the PCL matrix resulted in substantial decrease of the electrical resistivity of the composites as the MWCNTs loading was increased from 0 to 2.0 wt%. Furthermore, thermal stability of the PCL and PCL/MWCNTs-COOH composites were investigated using the data acquired from the thermogravimetric analysis. The detailed kinetics of the thermal degradation of the composites was investigated by analyzing their thermal behavior at different heating rates in a nitrogen atmosphere. Activation energy of thermal degradation was determined by using the equations proposed by Kissinger and Flynn-Wall-Ozawa. The apparent activation energy of PCL/MWCNTs-COOH composite was considerably higher than that of neat PCL.

• Current Research on Agriculture and Life Sciences
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• v.5
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• pp.68-74
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• 1987

The growth of A calcoaceticus C10 in CL medium was not increased by the addition of 0.5% E-capralactone or succinate, but increased by 0.2% adipate, xylose or even glucose which was not metabolized as a carbon source. The addition of 0.2% glucose after culture in CL medium for 6 hours increased the growth of A. colcoaceticus C10 twice as much as that in CL medium after culture for further 10 hours. Biosynthesis of cyclohexanol dehydrogenase in A. calcoaceticus C10 was not repressed by ${\varepsilon}$-caprolactone, succinate, xylose and glucose, but repressed by adipate which is endproduct of cyclohexanol metabolism. The induction of dehydrogenase by cyc1ohexanol in CL medium was not repressed completely by 0.1% adipate, but repressed almost completely by 0.2% adipate in A. calcoaceticus C10.

• Journal of Veterinary Clinics
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• v.32 no.3
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• pp.224-230
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• 2015

This study was designed in the fabricated poly (L-Lactic-co-${\varepsilon}$-Caprolactone) (PLCL) scaffold using chitosan-alginate hydrogel, which would be more suitable to maintain the biological and physiological functions continuing three dimensional spatial organizations for chondrocytes. As a scaffold, hydrogels alone is weak at endure complex loading within the body. In this study, we made cell hybrid scaffold constructs with poly (L-Lactic-co-${\varepsilon}$-Caprolactone) (PLCL) scaffold and hydrogels to make a three-dimensional composition of cells and extracellular matrix, which would be a mimic of a native cartilage. Using a particle leaching technique with NaCl, we fabricated a highly-elastic scaffold from PLCL with 85% porosity and $300-500{\mu}m$ pore size. A mixture of bovine chondrocytes and chitosan-alginate gel was seeded and compared with alginate as a control on the PLCL scaffold. The cell maturation, proliferation, extracellular matrix synthesis, glycosaminoglycans (sGAG) production and collagen type-II expressions were better in chondrocytes seeded in chitosan-alginate hydrogel than in alginate only. These results indicate that chondrocytes with chitosan-alginate gel on PLCL scaffolds provide an appropriate biomimetic environment for cell proliferation and matrix synthesis, which could successfully be used for cartilage repair and regeneration.

• Journal of Gastric Cancer
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• v.3 no.2
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• pp.93-96
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• 2003

Purpose: Synthetic absorbable monofilaments offer excellent glide characteristics and cause minimal tissue trauma as a result of their smooth monofilament structure and gradual absorption within the healing tissues. For these reasons, these suture materials are commonly used in various surgical fields such as gastroenterology, urology, gynecology, and plastic surgery. The aim of this study was to evaluate the safety and usefulness of a new synthetic absorbable monofilament, Glycoside-..-caprolactone-trimethylene carbonate interpolymer (GCT), in gastrointestinal anastomosis and closure. Materials and Methods: We evaluated 55 gastrointestinal anastomoses and closures using GCT $MONOSYN^{R}$, B. Braun, Germany) in 47 patients who underwent gastric surgery between December 2001 and May 2002 at Seoul National University Hospital. Patient's characteristics, operative procedure, surgeon's opinion of handling properties of GCT, and suture-related complications were analyzed. Results: There were 34 males and 13 females (M:F= 2.6:1) with an average age of 54.2 years old. Forty-five cases of gastrointestinal anastomosis (20 gastrojejunostomies and 25 jejunojejunostomies) and 10 cases of intestinal closure (7 gastrostomy closures and 3 duodenal stump closures) were performed in 41 cases of stomach cancer, three of peptic ulcer disease, two of GIST, and one MALToma. The handling properties of GCT according to the criteria of knot breaking load, knot security, and placing property were always scored with 7 to 9 points (10=excellent, 1=very poor). Two cases of postoperative complications ($3.6\%$) were noted. One was a leak of the gastrojejunostomy site which was successfully managed conservatively, and the other was a stricture of the gastrojejunostomy site which was managed by reoperation (side-to-side jejunojejunostomy). Conclusion: GCT seems to be an applicable suture material for various gastrointestinal anastomoses and closures.

• Elastomers and Composites
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• v.49 no.1
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• pp.13-23
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• 2014

In this work, glycolide, L-lactide and ${\varepsilon}$-caprolactone monomers were polymerized into the triblock copolymers by two step polymerization method and their non-isothermal crystallization behaviors were studied by combination of modified Avrami and Ozawa formula for further analysis of their behaviors. The result showed that PGCLA21 gave the highest value for supercooling analysis and super cooling degree increased with L-lactide content. Crystallization velocity constant, however, showed no significant change. The result of cooling function in specific relative crystallization degree showed that the increase of L-lactide content made an effect on the more enhancement of crystallization velocity of the PGCLA than PGCL. The result of big logF(T) value with the L-lactide content above critical point for PGCLA41 and PGCLA21 showed that bigger cooling velocity needed to gain same crystal size compared with PGCL. This means that it gives negative effect in the increase of crystallization velocity.