• 한국재료학회지
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• 제20권3호
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• pp.148-154
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• 2010

It is necessary to develop new methods to prevent catastrophic failure of structural material in order to avoid accidents and conserve natural and energy resources. Design of intelligent materials with a self-diagnosing function to prevent fatal fracture of structural materials was achieved by smart composites consisting of carbon fiber tows or carbon powders with a small value of ultimate elongation and glass fiber tows with a large value of ultimate elongation. The changes in electrical resistance of CF-GFRP/GFRP (carbon fiber and glass fiber-reinforced plastics/glass fiber-reinforced plastics) composites increased abruptly with increasing strain, and a tremendous change was seen at the transition point where carbon fiber tows were broken. Therefore, the composites were not to monitor damage from the early stage. On the other hand, the change in electrical resistance of CP-GFRP/GFRP (carbon powder dispersed in glass fiber-reinforced plastics/glass fiber-reinforced plastics) composites increased almost linearly in proportion to strain. CP-GFRP/GFRP composites are superior to CF-GFRP/GFRP composites in terms of their capability to monitor damage by measuring change in electrical resistance from the early stage of damage. However, the former was inferior to the latter as an application because of the difficulties of mass production and high cost. A method based on monitoring damage by measuring changes in the electrical resistance of structural materials is promising for improved reliability of the material.

• 한국폐기물자원순환학회지
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• 제35권8호
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• pp.683-691
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• 2018

The plastic strategy adopted by the EU in January 2018 was established to implement circular economic policies and the Sustainable Development Goals(SDGs) of the United Nations. The strategy includes the vision and implementation measures to achieve, which are primarily measures to improve recycling and increase demand for recycled plastics. The representative measures include the design that considers recycling possibilities, reinforcement of demand for recycled plastics, suppression of occurrence, and response to micro-plastics. The policies to implement these measures include legislative restrictions and economic measures (EPR, GPP). It is especially desirable that the policies are applied differently depending on the plastic product. The Korean government has established comprehensive measures for all stages from production to recycling, but those measures are not comprehensive compared to the EU's strategy. The reason is that the refusal of waste collection makes the Korean government establish the approach from the aspect of waste management instead of the implementation of a circular economy or SDGs like the EU. The countermeasures are aimed at achieving a 50% reduction in waste generation amount and a 70% recycling rate. It is considered that the possibility of achieving the goal will increase by examining the measures and policy means in the EU's plastics strategy.

• Korean Chemical Engineering Research
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• 제46권3호
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• pp.540-544
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• 2008

혼합플라스틱에 대한 열분해특성실험을 스테인레스 스틸의 회분식 미분반응기에서 수행하였으며, 혼합플라스틱의 혼합비율은 22 wt.% HDPE, 17 wt.% LDPE, 27 wt.% PP, 12 wt.% PS, 16 wt.% ABS, 6 wt.% PVC이었다. 열분해온도는 $410{\sim}450^{\circ}C$ 이었으며 각 열분해생성물의 수율은 무게측정을 통해 얻었으며, 액상생성물의 분자량분포는 GC-SIMDIS 방법을 통해 측정하였다. 혼합플라스틱 열분해의 경우 반응온도와 시간이 증가할수록 고상잔류물의 수율증가와 액상생성물의 수율감소 그리고 액상생성물의 평균 분자량 감소가 두드러졌다. 혼합플라스틱에 포함된 PVC의 약 20%가 염소가스형태로 배출됨을 알 수 있었다. 혼합플라스틱 열분해에서 말단절단의 속도계수인 활성에너지 값은 50.2 kcal/mole 이었다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.154-159
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• 2004

In this study, in order to perform more efficiently reliability design and integrity assessment of structural members, the relational database management program on the engineering plastics was constructed. This program contained 476 grades for 14 kinds of the engineering plastics and was developed using MS-access and MS-visualbasic. This program consists of 3 modules; search condition, probabilistic characteristics of material property, evaluation of P-S-N curve. We perform fatigue test for probabilistic durability analysis and this results input the database program to estimate P-S-N.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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• pp.235-238
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• 2003

Thermo-plastic has generally bad electrical characteristics at high temperature comparing to thermoset-plastics when the plastic apply to electrical power apparatus as an electrical insulator. To solve the problem, we study engineering plastics such as Polyamide and Polyphthalamide as a base resin. And filler of the engineering plastics is glass fiber. Electrical characteristics studied are permittivity, loss factor and breakdown strength according to temperature and frequency of measuring signal. Electrical characteristics of Polyphthalamide has good temperature and frequency dependency comparing to those of Polyamide.

• Advances in concrete construction
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• 제13권 2호
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• pp.113-121
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• 2022

Polymers, particularly plastics, have been widely seen as an existential risk to the environment due to their contribution to pollution, carbon emissions and climate change. Many argue that it is possible to substantially ease the threat of plastics by engaging the public in reducing their use in day-to-day life and implementing efficient domestic waste management strategies. On the other hand, polymers and plastics in building and construction are considerably less problematic, if not attractive. In fact, the applications of polymers in construction have been continuously expanding. This is partly due to the developments made in this area being implemented within a sustainable development strategy. In this paper, the main applications of polymers in construction have been revisited and an overview of the research topics in each application has been briefly presented.

• 콘크리트학회논문집
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• 제18권1호
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• pp.117-124
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• 2006

본 연구에서는 복합 재질 폐플라스틱(PA)을 이용한 폴리머콘크리트의 작업성, 경화시간 및 경화수축에 미치는 결합재 첨가량 및 PA 혼입량의 영향에 대하여 검토하였다. 그 결과 복합 재질 폐플라스틱을 재활용한 폴리머콘크리트의 작업성은 결합재 첨가량, PA 혼입량 및 필러 혼입량의 증가에 따라 증가하는 경향을 나타냈다. 복합 재질 폐플라스틱을 이용한 폴리머콘크리트의 경화시간은 촉매제 첨가량 및 양생온도의 증가에 따라 짧아지는 경향을 나타냈다. 복합 재질 폐플라스틱을 이용한 폴리머콘크리트의 길이변화는 결합재 첨가량 및 PA 혼입량의 증가에 따라 증가하는 경향을 보였다. 본 연구 결과가 복합 재질 폐플라스틱 종말품의 재활용에 조금이나마 기여할 수 있을 것을 기대하며 향후 지속적인 연구개발을 통하여 더욱 광범위한 복합재질 폐플라스틱 종말품의 재활용이 이루어질 수 있을 것으로 판단된다.

• 한국해양공학회지
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• 제14권1호
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• pp.52-59
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• 2000

Flexural fracture characteristics of newly-developed Grid-type carbon fiber plastics in the deteriorated reinforced concrete structures were investigated by the four-points fracture test to verify the strengthening effects in the beam specimens. Results showed that initial cracks appeared in the boundary layers of fibers embedded in the newly-placed mortar concrete slowly progressed to the direction of supports and showed fracture of fiber plastics and brittle failure of concrete in compression in sequence after the yielding of steel reinforcement. Accordingly the reasonable area of Grid-type carbon-fiber plastics in the strengthening design of deteriorated RC structures should be limited and given based on the ultimate strength design method to avoid the brittle failure of concrete structures.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1998년도 봄 학술발표회 논문집
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• pp.63-66
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• 1998

The steady growth in the use of plastic materials in packaging applications has caused an increasing concern about the environment and the problem of solid waste disposal. Therefore, the recycling of plastics is the very important problem, which must be solved technically and environmentally [1]. It is technically feasible to recycle, recover and reuse all of the plastics discarded, but economics limit the degree of recycling at this time.(omitted)

• 소성∙가공
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• 제24권6호
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• pp.443-450
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• 2015