• 폴리머
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• 제32권2호
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• pp.178-182
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• 2008

생분해가 가능한 셀룰로오스 디아세테이트(CDA)/탄산칼슘($CaCO_3$) 복합체를 용융가공을 통하여 제조하였고, 그 특성을 연구하였다. 용융가공을 위하여, 혼합체에 가소제로 트리아세틴(TA)과 윤활제로서 소량의 에폭시화된 콩기름(epoxidized soybean oil)을 첨가하였으며 가공시 최적 조건을 확립하였다. CDA와 TA의 아세틸기($-OC(O)CH_3$)가 용융가공 중에 열분해 되어 초산($CH_3COOH$)을 발생시키는데, 탄산칼슘의 함량(wt%)이 증가할수록 초산($CH_3COOH$)의 흡수효과(absorption effects)가 향상되며, 탄성률과 $T_g$가 증가하였다. 탄산칼슘의 함량이 증가할수록 인장강도와 신율은 감소하였다.

• 한국정밀공학회지
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• 제24권4호
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• pp.138-146
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• 2007

Some biodegradable polymers and other materials such as hydrogels have shown the promising potential for surgical applications. Post surgical adhesion caused by the natural consequence of surgical wound healing results in repeated surgery and harmful effects. Recently, scientists have developed absorbable anti-adhesion barriers that can protect a tissue from adhesion in case they are in use; however, they are dissolved when no longer needed. Although these approaches have been attempted to fulfill the criteria for adhesion prevention, none can perfectly prevent adhesions in all situations. Overall, we developed a new method to fabricate an anti-adhesion membrane using biodegradable polymer and hydrogel. It employed a highly accurate three-dimensional positioning system with pressure-controlled syringe to deposit biopolymer solution. The pressure-activated microsyringe was equipped with fine-bore nozzles of various inner-diameters. This process allowed that inner and outer shapes could be controlled arbitrarily when it was applied to a surgical region with arbitrary shapes. In order to fulfill the properties of the ideal barriers f3r preventing postoperative adhesion, we adopted the pre-mentioned method combined with surface modification with the hydrogel coating by which anti-adhesion property was improved.

• Restorative Dentistry and Endodontics
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• 제41권2호
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• pp.121-129
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• 2016

Objectives: The purpose of this study was to assess the effect of single and combined applications of fluoride on the amount of fluoride release, and the remineralization and physical properties of enamel. Materials and Methods: Each of four fluoride varnish and gel products (Fluor Protector, FP, Ivoclar Vivadent; Tooth Mousse Plus, TM, GC; 60 Second Gel, A, Germiphene; CavityShield, CS, 3M ESPE) and two fluoride solutions (2% sodium fluoride, N; 8% tin(ii) fluoride, S) were applied on bovine teeth using single and combined methods (10 per group), and then the amount of fluoride release was measured for 4 wk. The electron probe microanalysis and the Vickers microhardness measurements were conducted to assess the effect of fluoride application on the surface properties of bovine teeth. Results: The amount of fluoride release was higher in combined applications than in single application (p < 0.05). Microhardness values were higher after combined applications of N with FP, TM, and CS than single application of them, and these values were also higher after combined applications of S than single application of A (p < 0.05). Ca and P values were higher in combined applications of N with TM and CS than single application of them (p < 0.05). They were also increased after combined applications of the S with A than after single application (p < 0.05). Conclusions: Combined applications of fluoride could be used as a basis to design more effective methods of fluoride application to provide enhanced remineralization.

• 문화기술의 융합
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• 제8권2호
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• pp.349-354
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• 2022

본 연구는 PBAT(Poly Butylene Adipate-co-Terephthalate)와 PLA(Poly Lactic Acid)를 사용하여 수지의 컴파운드와 생분해성 멀칭필름의 내가수분해성과 기계적 물성을 향상시키기 위하여 수행되었다. 어닐링 온도조건에 따른 다양한 비율의 사슬연장제와 기계적 물성을 검토하였다. 어닐링공정은 컴파운드 수지의 결정화 능력을 향상시킬수 있음을 나타내었다. 사슬연장제의 첨가로 인장강도를 향상시킬 수 있었으며, 필름의 내가수분해성도 증가하였다. 사슬연장제 0.6phr. 첨가의 경우에 인장강도는 383.0Kgf/cm²으로 대조 필름과 비교하여 155% 향상되었다. 팽창비(BUR)가 2.5일 때, 필름의 최적 인장강도는 기계 방향(MD)과 가로 방향(TD) 에서 379.0/195.2kgf/cm²까지 크게 증가하였다.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1997년도 춘계학술발표회 논문집
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• pp.328-332
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• 1997

Hot stretching focused on the improvement of properties of poly(L-lactic acid) fiber. Some aliphatic polyesters are biodegradable under microbial attack and the new unique applications are expected. Generally, these materials have a somewhat low melting temperature and low mechanical properties compared with the aromatic polyesters. In this study, melt-spinning of poly(L-lactic acid) was conducted. We investigated effects of the stretching and the molecular orientation of aliphatic polyester fibers on the change of fine-structure. Glass transition temperature, molecular orientation and crystallinity increased according to the increase of stretching ratio.

• 약학회지
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• 제31권3호
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• pp.182-188
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• 1987

Simple coacervation of bovine serum albumin was studied to prepare biodegradable microacapsule. Albumin microcapsules were prepared by using acrylonitrilestyrene polymer (M-80) resin beads and sulfamethoxydiazine as the core materials. The albumin to beads ratio was found to be 1:2.3 and the albumin to sulfamethoxydiazine ratio to be 1:2.9. The 50% release times (T$_{50%}$) of sulfamethoxydiazine and microencapsulated sulfamethoxydiazine were 6 min. and 73 min., respectively. The surface appearance of the microcapsule collected after release experiment was not different from those of the original microcapsule. In addition to slowing release of drug the microencapsulation process masked characteristic bitter taste of sulfamethoxydiazine.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2015년도 춘계학술대회 논문집
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• pp.179-180
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• 2015

pure Mg and some Mg alloys are relatively rapidly corroded after operation, resulting in the decrease of mechanical strength and change of local ion concentration. In this study, the corrosion mechanism of biodegradable implant materials was investigated by corrosion tests of the Mg alloy in Hank's solution. Particularly, the crystal structures and chemical bonding state of corrosion reactants was systematically examined.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1252-1252
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• 2001

The aim of this study was to evaluate the possibility to characterize and classify waxes applied on some type of cheeses to obtain good stability during handling and transportation. Generally, waxes are obtained from the petrochemical industry, nowadays there is the possibility to also use biodegradable waxes produced from microorganisms. Preliminary studies were carried out to optimize sample presentation in NIR analysis, such as melting conditions (influence of temperature) and coat thickness of wax. 12 waxes (biodegradable or not) were analysed by using an InfraAlyzer 500 (Bran+Luebbe). The sample size was performed cutting pieces of 1.5 cm (height) x 1.5 cm (width) x 1.5 mm (thickness), previously melted at 9$0^{\circ}C$. NIR spectra were collected at room temperature, and data were processed by Sesame Software (Bran+Luebbe) to evaluate qualitative differences among samples by cluster analysis. Waxes were gathered on the basis of their origin (petrochemical or microbial). To better understand the significance of the NIRS bands discriminating among waxes, a two-dimensional correlation with FT-IR spectra, collected by a FT-IR/ATR 420 (JASCO) instrument, was made using 2DCORR program (Galactic Industries). On the basis of its classification power, NIRS appears to be a promising tool when used in routine analysis for a qualitative control of raw materials.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1265-1270
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• 2007

Conventional methods for fabricating three-dimensional (3-D) scaffolds have substantial limitations. In this paper, we present 3-D scaffolds that can be made repeatedly with the same dimensions using a microstereolithography system. This system allows the fabrication of a pre-designed internal structure, such as pore size and porosity, by stacking photopolymerized materials. The scaffolds must be manufactured in a material that is biocompatible and biodegradable. In this regard, we synthesized liquid photocurable biodegradable TMC/TMP, followed by acrylation at terminal ends. And also, solidification properties of TMC/TMP polymer are to be obtained through experiments. Cell adhesion to scaffolds significantly affects tissue regeneration. As a typical example, we seeded chondrocytes on two types of 3-D scaffold and compared the adhesion results. Based on these results, the scaffold geometry is one of the most important factors in chondrocyte adhesion. These 3-D scaffolds could be key factors for studying cell behavior in complex environments and eventually lead to the optimum design of scaffolds for the regeneration of various tissues, such as cartilage and bone.

• 한국환경보건학회지
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• 제31권5호
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• pp.404-410
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• 2005

The pH efforts on the removal of 1,4-dioxane and the biodegradobility enhancement of dioxane contaminated water were investigated using $O_3/H_2O_2$ baled advanced oxidation process. Experiments were conducted using a bubble column reactor under different initial pH. The $O_3/H_2O_2$ process effectively converted 1,4-dioxane to more biodegradable intermediates which had a maximum $BOD_5$ enhancement at pH 11 within the experimental range, precisely, when the initial pH increased, $BOD_5$ enhanced. However, in case of removal efficiencies of 1,4-dioxane during $O_3/H_2O_2$ oxidation the optimum condition was shown at pH 9 compared with pH 6 and 11. TOC and COD values were not largely changed for all reaction time. From the results of 1,4-dioxane removal efficiency, TOC, COD, and $BOD_5$ enhancement with reaction time, it was surely observed that 1,4-dioxane was just converted to biodegradable materials, not completely oxidized to carbon dioxide.