• The monthly packaging world
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• s.56
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• pp.152-159
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• 1997

• Composites Research
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• v.36 no.2
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• pp.126-131
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• 2023

Growing environmental concerns regarding pollution caused by conventional plastics have increased interest in biodegradable polymers as alternative materials. The purpose of this study is to develop a 100% biodegradable nanocomposite material by introducing organic nucleating agents into the biodegradable and thermoplastic resin, poly(lactic acid), to improve its properties. Accordingly, cellulose nanofibers, an eco-friendly material, were adopted as a substitute for inorganic nucleating agents. To achieve a uniform dispersion of cellulose nanofibers (CNFs) within PLA, the aqueous solution of nanofibers was lyophilized to maintain their fibrous shape. Then, they were subjected to primary mixing using a twin-screw extruder. Test specimens with double mixing were then produced by injection molding. Differential scanning calorimetry was employed to confirm the reinforced physical properties, and it was found that the addition of 1 wt% CNFs acted as a reinforcing material and nucleating agent, reducing the cold crystallization temperature by approximately 14℃ and increasing the degree of crystallization. This study provides an environmentally friendly alternative for developing plastic materials with enhanced properties, which can contribute to a sustainable future without consuming inorganic nucleating agents. It serves as a basis for developing 100% biodegradable green nanocomposites.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.379-380
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• 2002

Biodegradable polymers have been regarded as a good alternative to solve the plastic waste problems caused by nondegradable synthetic polymers such as polyethylene and polystyrene. In the soil environment, plastics are mainly being used as a mulching film for agricultural purposes. In this research, the miscibility, tensile properties and biodegradation effect of poly-${\varepsilon}$-caprolactone(PCL) with polyvinyl chloride(PVC) have been studied. After 8 weeks of biodegradation, PCL/PVC(9/91) blend surface showed newly formed many holes. Consequently, the antiplasticization phenomenon and biodegradation were observed in the PCL/PVC blends. It was confirmed that a test for general biodegradation condition can be applied to plastic biodegradation in soil.

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.388-389
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• 2003

전기방사를 이용하여 나노섬유를 제조하려는 많은 연구가 진행되고 있다. 고분자 재료 측면에서 피브로인, 키토산, 콜라겐 등 천연고분자는 생분해성, 생체적합성, 환경친화성이 뛰어나 이들을 나노섬유소재로 개발할 경우 의료용소재 뿐만아니라 생명공학소재로서의 이용가능성이 크다. 특히, 실크피브로인은 생체적합성, 산소투과능, 세포부착능 둥 생체재료로서의 성능뿐만 아니라 우수한 물성과 기계적 성질을 가지고 있으므로 다양한 형태로 성형화시킴으로써 소재 성능을 높일 수 있다. (중략)

• Polymer(Korea)
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• v.33 no.6
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• pp.620-624
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• 2009

Biomedical metal implants have been used clinically for replacement, restoration, or improvement of injury bodies based on high mechanical properties, but it has some risks such as the inflammatory, late thrombosis, or restenosis due to the low biocompatibility and toxicity. In various techniques of surface treatment developed to preserve these drawbacks, this study examined the electrospray coating technology with biodegradable poly (lactic-co-glycoic acid) (PLGA) on metal surface. Based on fundamental examination of electrospraying and solution parameters, the surface morphology of coated film was closely related to the boiling point of solvent, in-flight distance, and droplet size. The thickness of polymer film was linearly proportional to the emerged volume. This result exhibits that the polymeric droplets were continuously deposited on the polymer film. Therefore, the electrospray coating technology might be applied into the fabrication of single/multi-layered polymer film in nano-/micro-thickness and the control of the topology for biomedical metal implants including stents.

• Journal of the Korean Wood Science and Technology
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• v.28 no.3
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• pp.34-41
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• 2000

Recently many scientists have tried to synthesize biodegradable polymers due to durable and non-biodegradable products of conventional synthetic plastics when these were wasted in nature. So to reuse the wastepapers for biodegradable polymer resources, ONP (old newsprint), OCC (old corrugated containerbpard) were carried out by the pretreatment of chlorinite, hypochlorite and oxygen-alkali treatment conditions. For manufacturing of biodegradable polymer with wastepaper, this study performed to investigate change of chemical components and optimal pretreatment condition. The summarized results in this study were as follows: Lignin content in ONP and OCC was was higher than in MOW and ash content was the highest in MOW. More amount of ash components were reduced by wet defiberation than by dry defiberation. Wet defiberation fiber are better than dry defiberated fiber in chemical pretreatment condition for wastepapers, and the best result was obtained in the condition of sodium chlorite at $70^{\circ}C$, because it has high delignification ratio, ${\alpha}$-cellulose contents and degree of polymerization in this treatment condition. Oxygen-alkali treatment condition is the worst method because of low yield, low degree of polymerization in this pretreatments.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.11a
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• pp.43.1-43.1
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• 2009

Bone plate는 골절된 뼈의 골 유합을 지지하기 위해서 정형외과, 신경외과, 성형외과 및 치과 등에서 널리 사용되고 있다. 하지만 기존의 bone plate는 대부분 금속으로 제작되어 있어 장기간 이식에 따른 부식 및 천연골 강도저하 등으로 인해 1~2년 후 재수술을 해야 하는 문제점을 갖고 있다. 본 연구에서는이런 금속 bone plate의 단점을 개선하고자 생체적합성이 우수한 생분해성 고분자 bone plate를 제작하였다. 사용된 고분자는 생체적합성과 생분해성이우수한 PVA(polyvinly alcohol)와 강도를 유지하기 위한 PMMA(poly methyl methacrylate)를 사용였다. Electrospinning 법으로 PVA와 PMMA fibrous mat를 제작하여 각 mat를 적층시킨 후 열압착을 하여 강도를 증가시킨 PMMA/PVA Mutlilayer bone plate을 제작하였다. 제작된 PMMA/PVA Mutlilayer bone plate의 생체적합성 평가를 위해 MTT assay, 생분해 특성을 관찰하기 위해 Micro-CT와 SBF(simulated body fluid) 내에서의 용해도를 관찰하였다. 또한조골세포의 부착과 분화에 미치는 영향을 SEM(scanning electron microscope)을통해 관찰하였고, 조골세포의 유전자 발현에 미치는 영향을 RT-PCR을통해 확인하였다.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2007.04a
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• pp.410-415
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• 2007

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.06a
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• pp.213-214
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• 2007

• Applied Chemistry for Engineering
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• v.3 no.3
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• pp.386-394
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• 1992