• 공업화학
• /
• 제16권6호
• /
• pp.800-808
• /
• 2005

미생물에 의해 분해되는 랩제조용 복합수지를 개발하고, 이에 대한 제조과정과 물성에 대하여 연구하였다. 이런 목적을 위해 원재료 수지, 산화제, 활제의 종류와 사용량 등 같은 몇 가지 조건을 최적화하였다. 생분해성 랩을 제조하기 위한 복합수지는 polyester 계열에서 PBAS (아디프산, 숙신산 및 1.4-부탄디올의 3성분 공중합체)와 PBAST (숙진산, 아디프산, 디메틸테레프탈레이트 및 1.4-부탄디올의 4성분 공중합체)를 이용하였다. 또한 PBAS에서는 1차 산화방지제로는 Irganox 1010과 1076 (0.1 phrs), 2차 산화방지제로는 Irgafos TNPP (0.2 phrs), PBAST에서는 1차 산화방지제로 Irganox 1076 (0.1 phrs), 2차 산화방지제로 Mark PEP 36 (0.3 phrs)이 가장 좋았다. 수지의 가공성 향상을 위해서 사용하는 활제로는 PBAS에서는 glycerol monostearate, PBAST에서는 palmityl alcohol를 각각 0.8%와 1.0%를 사용하면 충분하였다. 제조된 랩의 안정성은 중금속 용출실험과 UTM을 이용한 인장강도 및 신축률을 측정하여 평가하였다. 시제품에 대한 분해률을 측정하기 위해서 동일 조건의 토양에 매립하여 시간경과에 따른 분해정도를 비교한 결과 40일 정도가 경과하면 약 60%가 분해하는 것으로 나타났다.

• Journal of Plant Biotechnology
• /
• 제36권3호
• /
• pp.202-206
• /
• 2009

In many countries including China and U.S., researchers are developing methods to use sweetpotato as raw material for biofuel. We consider the sweetpotato is not only a source of green fuel, it eventually will provide various material including paper, adhesives, biodegradable plastics, and secondary metabolites. Sweetpotato is one of the high efficiency crop because it yields more calories per unit area than either maize or potato, and it requires the shortest growing cycle of the root crops grown in the tropics. Sweetpotato is the most useful crop for the coming starchbased industry era. Sweetpotato genetic resources are collected, characterized, evaluated, and maintained by U.S., China, Japan, and the International Potato Center. New varieties of sweetpotato using the proper genetic resources and molecular breeding will be developed to cope with the global food and energy in 21st century.

• Structural Engineering and Mechanics
• /
• 제76권5호
• /
• pp.613-618
• /
• 2020

Exhausting oil resources and increasing pollution around the world are forcing researchers to look for new, renewable, biodegradable materials to lead sustainable development. The use of fiber reinforced composites based on natural fibres has increasingly begun as prospective materials for various engineering applications in the automotive, rail, construction and aerospace industries. The natural fiber chosen to make the composite material is plant-based fibre, e.g. jute fibre, and hemp fibre. Thermosetting polymer based Epoxy (LY556) was utilized as matrix material and The composites were produced using hand lay-up technique. The fabricated composites were tested for acoustic testing, thermo-gravimetric analysis (TGA) and flammability testing to asses sound absorption, thermal decomposition and fire resistivity of the structures. Hemp fibre composites have shown improved thermal stability over Jute fibre composites. However, the fire resistance characteristics of jute fibre composites are better as compared to hemp fibre composites. The sound absorption coefficient of composites was found to enhance with the increase of frequency.

• Biotechnology and Bioprocess Engineering:BBE
• /
• 제9권4호
• /
• pp.318-322
• /
• 2004

Lactic acid is an environmentally benign organic acid that could be used as a raw material for biodegradable plastics if it can be inexpensively produced by fermentation. Two genes (ldhL and ldhD) encoding the L-(+) and D-(-) lactate dehydrogenases (L-LDH and D-LDH) were cloned from Lactobacillus sp., RKY2, which is a lactic acid hyper-producing bacterium isolated from Kimchi. Open reading frames of ldhL for and ldhD for the L and D-LDH genes were 962 and 998 bp, respectively. Both the L(+)- and D(-)-LDH proteins showed the highest degree of homology with the L- and D-lactate dehydrogenase genes of Lactobacillus plantarum. The conserved residues in the catalytic activity and substrate binding of both LDHs were identified in both enzymes.

• 접착 및 계면
• /
• 제9권2호
• /
• pp.1-7
• /
• 2008

생분해성이 있는 polycaprolactone을 사용하여 용액 상태에서 건조시키는 방법으로 마이크로 캡슐을 제조하였다. 심물질로는 화장품 분야에서 중요한 성분으로 쓰이는 retinol을 선택하였으며 안정제로는 poly(vinyl alcohol)을 사용하였다. 제조 조건에 따른 마이크로캡슐의 형태 변화와 물성 변화를 scanning electron microscope와 differential scanning calorimeter를 이용하여 측정하였으며 심물질의 방출 속도에 미치는 영향들을 UV를 이용하여 측정하였다. 사용한 벽재 물질 용액의 농도, 교반속도, 안정제의 농도 등을 변화 시켜 가면서 마이크로캡슐을 제조하여 보았으며, 최적 조건에서 지름이 5~6 um인 구형 모양의 균일한 크기를 갖는 마이크로캡슐들이 형성되었음을 확인하였다.

• 한국의상디자인학회지
• /
• 제17권2호
• /
• pp.125-143
• /
• 2015

This study has investigated the status of utilizing 3D printing in fashion field in order to keep up with the trend for 3D printing technology to be realized in all industries so that the materials and the modeling modes may be figured out. The following is the findings. The materials used most in 3D printing in fashion field are PA, PLA, TPU, multi-material, ABS and metal. PA, TPU and Multi-material have so much excellent flexibility and strength that they are widely used for garment, shoes and such fashion items as bags. But PLA, ABS and metal are scarcely used for garment because PLA is easily biodegradable in the air, ABS generates harmful gas in the process of manufacture and metal is not flexible, while all of these three are partly used for shoes and accessories. The modeling modes mainly applied for 3D printing in fashion field are SLS, SLA, FDM and Polyjet. SLS, which is of a powder-spraying method, is used for making 3D textile seen just like knitting. Polyjet method, which has higher accuracy and excellent flexibility, can be used for expressing diverse colors, and accordingly it is used a lot for high-quality garment, while SLA and FDM method are found to be mostly used for manufacturing shoes and accessories rather than for making garment because they are easily shrunk to result in deformation.

• 한국토양비료학회지
• /
• 제49권3호
• /
• pp.227-234
• /
• 2016

The influence of mixing on biogas production and organic material removal performance of solid state anaerobic digestion of dairy manure and sawdust bedding mixtures was evaluated using 22 L volume lab-scale digesters. After 45 days of anaerobic digestion at $37^{\circ}C$, cumulative methane yield of unmixed test unit ($73.1N{\cdot}mL/g-VS$) was almost 1.3 times of that of mixed one ($56.3N{\cdot}mL/g-VS$). The biodegradable volatile solids removal rate of unmixed test unit was 67%, which was almost 28% greater than mixed one. Our results reveal that unmixed condition is better than mixed one in terms of biogas production and organic material reduction.

• Corrosion Science and Technology
• /
• 제16권2호
• /
• pp.85-89
• /
• 2017

One of the most challenging issues in the oil and gas industry is corrosion assessment and management in subsea structures or equipment. At present, almost all steel pipelines are sensitive to corrosion in harsh working environments, particularly in salty water and sulphur ingress media. Nowadays, the most commonly practiced solution for a damaged steel pipe is to entirely remove the pipe, to remove only a localized damaged section and then replace it with a new one, or to cover it with a steel patch through welding, respectively. Numerous literatures have shown that fiber-reinforced polymer-based composites can be effectively used for steel pipe repairs. Considerable research has also been carried out on the repair of corroded and gouged pipes incorporated with hybrid natural fiber-reinforced composite wraps. Currently, further research in the field should focus on enhanced use of the lesser and highly explored hybrid-biocomposite material for the development in corrosion prevention. A hybrid-biocomposite material from renewable resource based derivatives is cost-effective, abundantly available, biodegradable, and an environmentally benign alternative for corrosion prevention. The aim of this article is to provide a comprehensive review and to bridge the gap by developing a new hybrid-biocomposite with superhydrophobic surfaces.

• Korean Chemical Engineering Research
• /
• 제49권3호
• /
• pp.306-313
• /
• 2011

젖산(lactic acid)은 식품, 의약품, 화학약품 등의 원료로서 많이 사용되고 있으며, 생분해성 고분자(biodegradable polymer)인 폴리젖산(polylactic acid)의 원료로서 최근 사용량이 증가하고 있다. 하지만 고비점 물질의 존재와 젖산의 비휘발성은 젖산 분리 및 정제를 어렵게 만든다. 이를 극복하기 위해 분리벽형 반응 증류를 이용하여 비휘발성 물질인 젖산을 에스테르화 반응에 의하여 휘발성이 있는 물질로 전환시킨 후 분리하고 가수분해반응을 이용하여 다시 젖산으로 전환하여, 회수하는 공정을 제안하였다. 제안된 연속적인 젖산회수 분리벽형 반응증류공정의 동특성을 조사하여, 이를 바탕으로 제어계들을 구성하였고 각 제어계들의 성능을 비교하였다.

• 수산해양기술연구
• /
• 제54권2호
• /
• pp.97-106
• /
• 2018

The objective of this study was to estimate physical properties and fishing performances of net twine with improved PBS copolymer resin (Bio-new), the existing PBS/PBAT blending resin (Bio-old) and commercial Nylon (Nylon). The tensile strength of Bio-new monofilament was equal to Bio-old and the elongation of Bio-new was about 6 % higher than that of Bio-old in wet condition. The physical properties tests were carried out to estimate breaking load and stiffness in dry and wet conditions, respectively. In the results, the breaking load of Nylon netting was the highest whereas the elongation of Bio-new was 1.4 times higher than that of Nylon netting in wet condition. The breaking load of Bio-old netting was about 9.2 % higher than that of Bio-new netting. However, the elongation of the Bio-new netting was about 3% higher than that of Bio-old. The stiffness of the Bio-new compared to Bio-old was improved about 34 % in dry condition and about 32 % in wet condition. The filed experiments of the fishing performance were conducted with three kinds of drift nets with different netting materials in the coastal sea of Jeju. The each experimental drift net made of different materials showed the similar fishing performance. Bio-old drift net yielded less catches of small sized yellow croaker than other drift nets. The netting materials affected the fishing performance and length distribution of catches in the drift nets.