• Proceedings of the Korean Fiber Society Conference
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• 1997.04a
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• pp.193-196
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• 1997

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.4
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• pp.133-140
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• 2010

The purpose of this study is to evaluate the new eco water tank which is made of high density polyethylene and concrete with low temperature cement. The strength and failure mode of eco water tank was examined through tensile test with mixture of concrete and HDPE, temperature monitoring for various kind of concrete, admixture contains etc. The strength and failure mode were examined through tensile test with mixture of concrete and HDPE, temperature monitering for different kinds of concrete, strength test with different admixtures etc. It was found that shear connector between concrete and HDPE effects significantly contributed to the combined structures. ㄱ type shear connector results in tensile strength of up to 40% compared to that of V type shear connector. Based on test result, the new eco composite tank improved the stability and safety the old one and demonstrated the applicability and capability.

• Polymer(Korea)
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• v.29 no.1
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• pp.32-35
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• 2005

In this paper, the carbon nanotubes (CNTs) were ozonized and the positive temperature coefficient (PTC) behaviors of CNTs-filled high-density polyethylene (HDPE) conductive composites were studied. The results of element analysis (EA) and FT-IR indicate that the oxygen-containing functional groups on the CNTs surfaces, such as O-H, C-O, and C＝O groups, were increased with the ozonization. Electrical resistivities of the CNTs/HDPE composites were measured by using a digital multimeter. The resistivity of the composites was increased abruptly near the crystalline melting temperature of the HDPE used as matrix, which could be attributed to the destruction of conductive network by the thermal expansion of HDPE. And, the PTC intensity of the CNTs/HDPE composites was increased with the increase of the ozone treatment time. It was probably due to the growing of maximum volume resistivity of the composites induced by the increased oxygen-containing functional groups in the CNTs surfaces.

• Proceedings of the Korean Fiber Society Conference
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• 1989.06a
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• pp.49-49
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• 1989

• The Korean Journal of Rheology
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• v.1 no.1
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• pp.63-70
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• 1989

고밀도 폴리에틸렌과 폴리프로필렌을 용융혼합하여 블렌드를 만들었다. 압출물의 morphology 와 유변학적 성질을 측정하고 그 용융하고 섬유의 X-선 회절, 인장 성질, 복굴 절률등과 관련하여 고찰하였다. 파단면의 SEM 사진으로부터 폴리에티렌 성분비가 25%, 50% 에서는 폴리프로필렌이, 75%에서는 폴리에틸렌이 연속상을 이루며 분산상은 고르게 분포함을 알았다 점도와 용융탄성은 모두 폴리에틸렌이 폴리프로필렌보다 크며 블렌드에서 는 그중간에 위치 하였다. 폴리에틸렌의 함량의 증가에 따라 압풀물의 제 1법선 응력차는 증가하였고따라서 방사 섬유의 복굴절률도 증가하였으며 초기 탄성률도 증가하는 경향을 보 였으나 결정 배향도는 조성 의존성을 갖지 않는다. 두 고분자의 비상용성으로 인해 강도는 짓선성에서 벗어나는 거동을 나타내었다.

• Journal of the Korean Chemical Society
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• v.55 no.4
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• pp.673-679
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• 2011

Bimodal high-density polyethylenes with different comonomer type and content were synthesized by polymerization of ethylene using Ziegler-Natta catalyst. Their structure and properties were studied using GPC, NMR, DSC and tensile test. It was found that ethylene/1-hexene copolymer exhibits higher tensile strength and elongation at break than that of ethylene/1-butylene copolymer with similar comonomer content. The molecular weight decreases as the comonomer content of the polymer increases. Short chain branching affects the crystallinity and thus the morphology and consequently the mechanical properties of the corresponding bimodal high-density polyethylenes. After SSA treated, the multiple endothermic peaks were observed. Multiple endothermic peaks are mainly attributed to the heterogeneity of ethylene sequence length and lamellar thickness. The difference of broadness index indicates that SCB distribution of polyethylene containing higher comonomer content has improved uniformity.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.137-138
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• 2019

The strengths and elastic modulus of high-density polyethylene in compression and tension met the minimum requirements of precast concrete products.

• Fire Science and Engineering
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• v.27 no.6
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• pp.44-49
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• 2013

As the polyethylene of high strength and ductility stabilized chemically has been mass-produced, it is spreading widely as material of industrial piping and water service piping. Recently, High density polyethylene (HDPE) pipe has been used even in water supply system of plant as buried pipe instead of cast iron pipe in domestic, but HDPE pipe has a probability of occurrence of damage if plant design and operating conditions are not considered. As a result of reviewing with respect of system design engineering based on operating conditions and verification test results, the specific design criteria for the use of HDPE piping in fire water supply system need to be established because of the possibility of crack damage due to water hammer.

• Polymer(Korea)
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• v.27 no.4
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• pp.307-312
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• 2003

Hollow fiber was prepared from the blend of a high density polyethylene (HDPE)/ultra high molecular weight polyethylene (UHMWPE). The changes in the morphology and mechanical property of the hollow fiber were investigated. The commercial product (Sterapore), having a high water permeability, was analyzed with viscosity measurement and FT-IR. The molecular weight of Sterapore was very high and its surface was coated with a vinyl alcohol/vinyl acetate copolymer. The content of UHMWPE in the HDPE/UHMWPE blend was limited below 10 wt%. In order to improve the dispersion of UHMWPE, a mineral oil should be introduced in the blend. The morphology and mechanical property of the hollow fiber of HDPE/UHMWPE blend were similar to those of the commercial product.

• Polymer Science and Technology
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• v.4 no.1
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• pp.12-22
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• 1993