• Title/Summary/Keyword: linear low density polyethylene

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Partial Discharge Characteristics in LLDPE-Natural Rubber Blends: Correlating Electrical Quantities with Surface Degradation

  • Aulia, Aulia;Ahmad, Mohd Hafizi;Abdul-Malek, Zulkurnain;Arief, Yanuar Z.;Lau, KwanYiew;Novizon, Novizon
    • Journal of Electrical Engineering and Technology
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    • v.11 no.3
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    • pp.699-706
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    • 2016
  • Partial discharges (PD) lead to the degradation of high voltage cables and accessories. PD activities occur due to the existence of impurities, voids, contaminants, defects and protrusions during the manufacture and installation of power cables. Commonly, insulation failures occur at cable joints and terminations, caused by inhomogeneous electric field distributions. In this work, a blend of natural rubber (NR) and linear low density polyethylene (LLDPE) was investigated, and the optimal formulation of the blend that could resist PD was discussed. The experiments were conducted under a constant high voltage stress test of 6.5 kV AC and the magnitude of partial discharge activities was recorded using the CIGRE method II. Pattern analysis of PD signals was performed along with the interpretation of morphological changes. The results showed that the addition of 10 wt% of NR and 5 wt% of Alumina Trihydrate (ATH) provided promising results in resisting PD activities. However, as the NR content increased, more micropores existed, thus resulting in increased PD activities within the samples.

A Study on the Properties of LDPE/LLDPE blends Prepared by Compositional Quenching Process (Compositional Quenching 공정에 의한 LDPE/LLDPE 블렌드의 물성에 관한 연구)

  • Cho, Soo-Min;Lee, Youngchul;Hwang, Seok-Ho;Lee, Sang-Won;Kim, Su-Kyung
    • Applied Chemistry for Engineering
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    • v.7 no.3
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    • pp.504-510
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    • 1996
  • Low-density polyethylene(LDPE)/Linear low-density polyethylene(LLDPE) blends were prepared by the compositional quenching process, a new morphology control method. The blends were characterized in terms of melting and crystallization behavior and mechanical properties. The results were compared with those of mechanically blended and solution blended samples. From DSC experiments, it was found that the melting temperatures and crystallization temperatures of the blends were dependent on the blending methods. In thermal property, LDPE/LLDPE blends prepared by compositional quenching process were similar to the blends prepared by solution blending but different from the blends prepared by mechanical blending. This result is explained to be due to the domain size dispersed in the matrix. The elongation-at-break and tensile strength of the samples blended by compositional quenching showed similar to those of the samples blended by solution blending method but larger than those of samples prepared by mechanical blending. Also, the Young's modulus showed the same trends as elongation-at-break. The tensile strength of the blends prepared by compositional quenching was not as high as the samples prepared by the other two blending methods.

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Studies on the Development of Biodegradable Plastics and Their Safety and Degradability (생붕괴성 플라스틱 포장재의 제조 및 제조된 소재의 안전성과 분해성 연구)

  • You, Young-Sun;Han, Jung-gu;Lee, Han-na;Park, Su-il;Min, Sea-Cheol
    • Food Engineering Progress
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    • v.15 no.3
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    • pp.257-261
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    • 2011
  • Biodegradable plastics were developed using biodegradable pellets made of corn stalk and rice husk and their safety as food packages and their biodegradability against light (ultraviolet (UV)), heat, and fungi were evaluated. Four kinds of 50-${\mu}m$ biodegradable plastics were produced by extruding the mixtures of the biodegradable pellets, low-density polyethylene (LDPE), high-density polyethylene (HDPE), and linear low-density polyethylene (LLDPE) with different compositions. Developed biodegradable plastics were safe to be used as food packages. The initial tensile strength and percentage elongation of the plastics were similar to those of LDPE, but the values decreased with increased their exposure time to UV and heat. The fungal biodegradability of the biodegradable plastics was higher than that of LDPE. The biodegradability of the biodegradable plastics shows the potential for them to be used as sustainable food packages.

Enhancement of Compatibility and Toughening of Commingled Packaging Film Wastes (혼합 폐포장 필름의 상용성 증진과 강인화)

  • Jeon Byeong-Hwan;Yoon Hogyu;Hwang Seung-Sang;Kim Jungahn;Hong Soon-Man
    • Polymer(Korea)
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    • v.29 no.2
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    • pp.127-134
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    • 2005
  • The relationships among mechanical properties, rheological properties, and morphology by reactive extrusion based on commingled pckaging film wastes contains polypropylene (PP) pckaging film system [PP/polyethylene (PE)/aluminum (Al)/poly(ethylene terephthalate) (PET)] and Nylon packaging film system[Nylon/PE/linear-low density polyethylene (LLDPE)] were investigated to improve the compatibility and toughness of these wastes using various compatibilizers such as ethylene vinylacetate (EVA), styrene-ethylene/butylene-styrene triblock copolymer (SEBS), styrene-ethylene/butylene-styrene-graft-maleic anhydride copolymer (SEBS-g-MA), polyethylene-graft-maleic anhydride (PE-g-MA), polypropylene-graft-maleic anhydride (PP-g-MA) , polyethylene-graft-acrylic acid (PE-g-AA) and polypropylene-graft-acrylic acid (PP-g-AA). Compared with simple melt blend system, the blends showed improvement of about $50\%$ increase in physical properties when SEBS and EVA were added. However, SEBS-g-MA thermoplastic elastomer which is highly reactive with amine terminal group of nylon, resulted in about $200\%$ increase in impact strength. This compatibilization effect resulted from the increase of interfacial adhesion and the reduction of domain size of dispersed phase in PP/Nylon blend system.

A Study on Recycling of Waste Polyethylene Film (폐폴리에틸렌 필름의 재활용에 관한 연구)

  • Lee, Hwan-Kwang
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.9 no.1
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    • pp.182-188
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    • 2008
  • The compounds of recycled polyethylene(PE) and fly-ashes were prepared. Polymers used were sorted PE from mixed plastics of household waste and Low Density Polyethylene(LDPE) and Linear Low Density Polyethylene(LLDPE) recycled from the scrap of packaging film plants. Fly-ashes were from the power plant and from the household waste incinerator. The tensile strength of recycled LDPE and LLDPE compounds decreased and the flexural modulus increased with greater amount of the power plant fly-ash. Anthracite fly-ash gave rise to slightly higher tensile and flexural strength of the LLDPE mixtures than bituminous coal fly-ash presumably due to higher content of unburned carbon. The incinerator fly-ash introduced to household waste PE enhanced both tensile strength and flexural modulus of the compounds. When LDPE and household waste PE were used together, the synergistic effect of incinerator fly-ash to household waste PE was offset by reduced crystallization of LDPE due to the filler particle. The compounds of household waste PE and incinerator fly-ash might be applied to structural materials for such as sewage pipe, which reduces the waste treatment cost and conserve the environment and resources.

Ultra-Drawing of Gel Films of Ultra High Molecular Weight Polyethylene/Low Molecular Weight Polymer Blends Containing $BaTiO_3$ Nanoparticles

  • Park Ho-Sik;Lee Jong-Hoon;Seo Soo-Jung;Lee Young-Kwan;Oh Yong-Soo;Jung Hyun-Chul;Nam Jae-Do
    • Macromolecular Research
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    • v.14 no.4
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    • pp.430-437
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    • 2006
  • The ultra-drawing process of an ultra high molecular weight polyethylene (UHMWPE) gel film was examined by incorporating linear low-density polyethylene (LLDPE) and $BaTiO_3$ nanoparticles. The effects of LLDPE and the draw ratios on the morphological development and mechanical properties of the nanocomposite membrane systems were investigated. By incorporating $BaTiO_3$ nanoparticles in the UHMWPE/LLDPE blend systems, the ultra-drawing process provided a highly extended, fibril structure of UHMWPE chains to form highly porous, composite membranes with well-dispersed nanoparticles. The ultra-drawing process of UHMWPE/LLDPE dry-gel films desirably dispersed the highly loaded $BaTiO_3$ nanoparticles in the porous membrane, which could be used to form multi-layered structures for electronic applications in various embedded, printed circuit board (PCB) systems.

The Electrical Properties of Film due to the Mixture Ratio of Linear Lour Density Polyethylene and Ethylene Vinyl Acetate (선형 저밀도 폴리에틸렌과 에틸렌 비닐아세테이트의 혼합비에 따른 박막의 전기적 특성)

  • 이충호;박찬원
    • Journal of the Korean Society of Safety
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    • v.14 no.2
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    • pp.83-89
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    • 1999
  • The electrical properties due to mixture ratio of linear low density polyethylene(LLDPE) and ethylene vinyl acetate(EVA) films are studied. An experimental specimen is selected as LLDPE/EVA of thickness 200${\mu}{\textrm}{m}$ produced by mixture ratio of 50 : 50, 60 : 40, 70 : 30 and 80 : 2 wt%. In temperature range from $25^{\circ}C$ to 12$0^{\circ}C$, the measurement of volume resistivity using a highmegohm meter is performed within 10 minutes since each voltage of DC 100 V, 250 V, 500 V and 1000 V is applied, according to the step voltage method. From FT-IR spectrum for an analysis of physical properties, it can be confirmed that LLDPE blended with EVA shows an absence of carbonyl groups(1735 $cm^{-1}$, C=0) and ether groups(1242 $cm^{-1}$, C-O). The peak of LLDPE and EVA made of mixture ratio of 70 : 30 at 2$\theta$ =21.4$^{\circ}$ in the results of XRD is higher than the others. In the experiment for volume resistivity characteristics in order to investigate the electrical properties of specimen, it is confirmed that volume resistivity is decreased with the increase of the molecular motion and temperature.

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Linear Low Density Polyethylene Preparation by Titanium-Based Ziegler-Natta Catalysts (티탄이 기본인 Ziegler-Natta 촉매에 의한 선형저밀도폴리에틸렌의 제조)

  • Dong-Ho Lee;Kyung-Eun Min;Cha-Ung Kim
    • Journal of the Korean Chemical Society
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    • v.31 no.1
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    • pp.110-117
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    • 1987
  • For the preparation of linear low density polyethylene (LLDPE), the copolymerization of ethylene and 1-butene was carried out with various catalysts of titanium alkoxidealkylaluminum compound in slurry phase. The effects of catalyst components, aging time, concentration of catalyst components, polymerization time and temperature on the catalytic activity and copolymer composition were examined. The properties of copolymer obtained were also considered with the correlation to the 1-butene contents. It has been found that the titanium tetra-n-butoxide-diethylaluminum chloride catalyst system was the most suitable for the production of LLDPE with higher catalytic activity, more 1-butene content and less soluble parts. The density, glass transition temperature, melting point and heat of fusion of copolymer were decreased with increasing 1-butene contents.

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Silicone/LLDPE 블랜드 필름의 난연특성 연구

  • 서동수;강영구
    • Proceedings of the Korean Institute of Industrial Safety Conference
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    • 2002.11a
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    • pp.149-153
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    • 2002
  • 1968년 Phillips Petroleum사에 의해 개발된 LLDPE(linear low density polyethylene)는 저가이며 인장강도, 연신율 등의 뛰어난 기계적 물성으로 인해 각종 필름, 코팅제, Cable용으로 사용되고 있다. 일반적으로 LLDPE의 용융점은 12$0^{\circ}C$정도이나 이보다 매우 낮은 온도에서 연화되어 기계적 물성이 급격히 저하되므로 Coating재료, 단열Cable, 내열성 Film분야 등의 용도에는 사용상 제약을 받는다. 반면 Silicone은 난연성, 내열성, 내화학특성 및 전기절연성이 우수하여 공업재료로 널리 사용되지만 기계적물성, 저온취성, 고가인 단점이 있어 용도에 따라 일반재료로는 사용하기 어렵다.(중략)

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Electrical Characteristic of Blend with LLDPE and EVA Due to Mixing Ratio (혼합비에 따른 선형저밀도 폴리에틸렌과 에틸렌비닐아세테이트 블랜드의 전기적 특성)

  • 신종열;이충호;홍진웅
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.14 no.6
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    • pp.525-532
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    • 2001
  • In this paper, physical properties and electrical characteristics of linear low density polyethylene(LLDPE) films blended with ethylene vinyl acetate(EVA), containing polar groups within it, were investigated to improve defects of polyethylene(PE) such like space charge accumulation and tree growth. Blending method changes super-structure of LLDPE, having a great influence on electrical characteristics. For analysis of physical properties, FTIR, XRD and DSC methods were executed, and for electrical characteristics, volume resistivity and dielectric strength were measured with the varying temperature. From the results, it is confirmed that bled specimens tend to be safe to varying temperature, and specially of 70:30 and 50:50 have a good performance.

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