High Density Polyethylene (HDPE) / Exfoliated Graphite (EFG) 나노복합필름 제조와 특성에 관한 연구

권혁,김도완,서종철 한국포장학회 2013 한국포장학회지 Vol.19 No.2

고밀도 폴리에틸렌(High density polyethylene, HDPE)을 수분에 민감한 전기전자제품, 의약품 등을 위한 하이배리어 패키징 소재로써 적용하기 위해서 높은 가로세로비(High aspect ratio)를 가진 Exfoliated graphite (이하 EFG)를 필 러로 도입하였다. 또한, 효과적인 분산성과 혼화성을 위해서 상용화제를 첨가하여 HDPE/EFG 나노복합필름을 제조하였 다. HDPE/EFG 나노복합필름의 EFG 함량에 따른 화학적 특성, 모폴로지(Morphology), 열적 특성 및 수분차단 특성을 조사하였다. HDPE와 EFG 사이에 화학적 결합이나 상호작 용이 약하지만, EFG를 첨가함에 따라 수증기 투과도는 127 에서 78 (70 μm·g/m2, day·atm)까지 감소되었다. 특히, HDPE/EFG 나노복합필름은 EFG의 함량이 0.5%일 때 가장 효과적이며, 그 이상의 함량에서는 물성이 향상되지 않았다. 따라서, 물성의 극대화를 위해서는 EFG의 분산성 향상 및 HDPE와 EFG의 화학적 결합 등의 혼화성 개선에 관한 추 가적인 연구가 필요하다. Exfoliated graphite (EFG) with high aspect ratio was incorporated with high density polyethylene (HDPE) for use as high barrier packaging material such as water-sensitivity electric product and pharmaceutical packaging. Also HDPE/EFG nanocomposite films were prepared by adding the compatibilizer for effective dispersion and compatibility. Their chemical properties, crystal structure properties, thermal properties and water barrier properties of as-prepared HDPE/EFG nanocomposite films were investigated as a function of EFG contents. It showed that there is a weak interfacial interaction between HDPE and EFG, however, the water vapor permeations were decreased from 127 to 78 (70 μm·g/ m2 ,day·atm) by addition of EFG. Especially, the physical properties of HDPE/EFG nanocomposite films were effectively increased up to 0.5 wt%, however, there were no significant improvement of properties in nanocomposite films at the additional EFG loading. To maximize their performance of the nanocomposite films, further research is required to enhance the dispersion of EFG and compatibility of EFG in HDPE matrix.

원자력발전소 적용 고밀도 폴리에틸렌 배관의 맞대기 융착절차 및 검증절차 분석

오영진,박흥배,신호상,Oh, Young-Jin,Park, Heung-Bae,Shin, Ho-Sang 대한용접접합학회 2013 대한용접·접합학회지 Vol.31 No.6

In nuclear power plants, lined carbon steel pipes or PCCPs (pre-stressed concrete cylinder pipes) have been widely used for sea water transport systems. However, de-bonding of linings and oxidation of PCCP could make problems in aged NPPs (nuclear power plants). Recently at several NPPs in the United States, the PCCPs or lined carbon steel pipes of the sea water or raw water system have been replaced with HDPE (high density polyethylene) pipes, which have outstanding resistance to oxidation and seismic loading. ASME B&PV Code committee developed Code Case N-755, which describes rules for the construction of buried Safety Class 3 polyethylene pressure piping systems. Although US NRC permitted HDPE materials for Class 3 buried piping, their permission was limited to only 10-year operation because of several concerns including the quality of fusion zone of HDPE. In this study, various requirements for fusion qualification test of HDPE and some regulatory issues raised during HDPE application review in foreign NPPs are introduced.

HDPE 용접 구조물에서 발생하는 변형에 관한 실험적 연구

강수지,이재민 대한용접접합학회 2023 대한용접·접합학회지 Vol.41 No.4

High-density polyethylene (HDPE) is increasingly recognized as an eco-friendly material for small crafts. However, there is limited research on welding distortion in HDPE welded structures. This study investigates the deformation behavior of HDPE fillet-welded specimens, focusing on global out-of-plane distortions such as angular and bowing distortions. Experimental analysis, conducted using an optical 3D scanner, reveals similarities between the observed deformation patterns in HDPE fillet-welded specimens and those commonly found in other fillet- welded structures. Angular and bowing distortion modes are primarily observed, resulting from the contraction forces that occur during the cooling process after the melting and solidification of the HDPE welding rod. Additionally, the influence of specimen thickness on deformations is examined. This research contributes valuable knowledge about welding distortions in HDPE, providing directions for optimization of welding processes and the enhancement of structural performance in HDPE welded structures.

Preparation and Characterization of Electrospun Mat of Ultra-high Molecular Weight Polyethylene/High-Density Polyethylene Blends

Prajesh Nayak,Anup K. Ghosh,Naresh Bhatnagar 한국섬유공학회 2023 Fibers and polymers Vol.24 No.10

Ultra-high molecular weight polyethylene (UHMWPE) acquires excellent properties while possessing poor processability. Blending low molecular weight polyethylene disentangles the molecular chain of UHMWPE and improves its processability, improving fiber productivity. In the present study, UHMWPE and its HDPE-blended fibers were produced by a high-temperature electrospinning process, and the effect of HDPE content on fiber properties was investigated in depth. Analysis of fiber surface morphology revealed the formation of uniformly distributed nano- to microscopic pores/pits, wrinkles, and grooves on the surface of blended fibers, unlike neat UHMWPE fibers containing irregular surface bulges and pits. It suggested that the blending of HDPE affected the surface topography and the thermal and mechanical properties of electrospun fibers. The tensile strength and Young’s modulus of UHMWPE fiber improved by 142 and 102% at a 67:33 mass ratio of UHMWPE and HDPE and by 84 and 132% in the case of a 50:50 composition ratio, respectively.

Preparation of De-crosslinked Polyethylene from Waste Crosslinked High-Density Polyethylene Using Supercritical Twin-Screw Extrusion

Cho Hang-Kyu,Kim Hansang 한국화학공학회 2024 Korean Journal of Chemical Engineering Vol.41 No.6

This study examined a method for de-crosslinking high-density polyethylene (HDPE) for use in heating pipes using supercritical fl uids and recycling them into polyethylene. Waste crosslinked HDPE is mostly incinerated because it is a thermosetting plastic and cannot be recycled. Therefore, there is an urgent need to develop new recycling technologies for crosslinked HDPE to prevent environmental pollution. Many experiments have been conducted under various subcritical and supercritical conditions using methanol as the supercritical solvent to recycle crosslinked HDPE. Consequently, PE can be prepared via a de-crosslinking reaction. To recycle crosslinked high-density polyethylene, we conducted experiments at three rotational speeds (80, 250, and 400 rpm) of the screw under the conditions of various temperatures (300–360 ) by using methanol, ethanol, acetone, and water. As a result, we could prepare polyethylene with a linear structure at temperatures above 300 through the de-crosslinking reaction. This study evaluated the characteristics of recycled polyethylene based on the reaction conditions using Fourier transform infrared spectroscopy (FT-IR), gel permeation chromatography (GPC), X-ray diff raction (XRD), diff erential scanning calorimetry (DSC), and tensile strength analyses. In this study, samples with the same chemical and crystal structures were prepared under all conditions.

Patterned grafting of acrylic acid onto polymer substrates

Kim, Dong-Ki,Choi, You Mee,Jung, Chan-Hee,Kwon, Ho-Je,Choi, Jae-Hak,Nho, Young-Chang,Suh, Dong-Hack,Ganesan, Ramakrishnan,Kim, Jin-Baek John Wiley Sons, Ltd. 2009 Polymers for advanced technologies Vol.20 No.3

<P>Polyethylene films were irradiated through a mask with high-energy argon ions to activate the surface for grafting. Acrylic acid was graft polymerized onto the irradiated region of the polyethylene surface. The grafted surface was characterized by using FT-IR and XPS. Patterned grafting of acrylic acid on the polyethylene surface was finally confirmed by a fluorescence labeling method. Copyright © 2008 John Wiley & Sons, Ltd.</P>

Feasibility study of shell element-based elastic FE approach for welding-induced thermal distortion prediction in HDPE welded structures

이재민 대한조선학회 2023 International Journal of Naval Architecture and Oc Vol.15 No.-

High-density polyethylene (HDPE) is considered an eco-friendly material for boat construction worldwide. However, managing thermal distortion in HDPE welding is challenging, impacting productivity. Traditional steel shipbuilding has established methods to predict welding-induced thermal distortion, but HDPE lacks comprehensive studies and standards. This research explores applying the elastic Finite Element (FE) approach, commonly used in steel structures, to HDPE welding. The elastic FE approach simplifies complex welding simulations, enabling its use in large structures like ship hulls. Our research assesses whether HDPE welded specimens exhibit similar distortion patterns to conventional welded structures and whether consistent parameters yield similar thermal distortion. Alignment between our FE analysis, based on specimen data, and experimental results validates the feasibility of using the elastic FE approach to predict HDPE thermal distortion. This study suggests it as a practical method to enhance HDPE boat manufacturing productivity.

와이어 압출 방법을 통한 HDPE 접합공정의 개선 형상별 실험적 연구

이충우,우수성,김지선 한국기계기술학회 2024 한국기계기술학회지 Vol.26 No.1

The overseas small ship market is witnessing a trend towards research aimed at substituting Fiber Reinforced Plastics (FRP), which poses environmental concerns, with High-Density Polyethylene (HDPE) in the shipbuilding process. Given the low melting point and high coefficient of thermal expansion of HDPE, research on joint areas is essential. This study focuses on preliminary investigations into ensuring the integrity of joints in shipbuilding processes using HDPE materials. Utilizing the Hot Gas Extrusion Welding method, which is conducive to joining large structures such as ships, HDPE joints were conducted. The material properties were evaluated based on the ASTM D638-14 international standards. This research aims to provide fundamental knowledge on the joining process of HDPE through Hot Gas Extrusion Welding and offers guidance on ensuring the integrity of joints in shipbuilding.

근위경골절골술(HTO)에 적용되는 X-band 플레이트의 경골틈새각(TGA)이 경골힌지의 인장강도에 미치는 영향

조문정(Moon-Jung Cho),황정훈(Jung-Hoon Hwang),한기봉(Gi-Bong Han),박종규(Jong-Kyu Park),김철웅(Cheol-Woong Kim) 대한기계학회 2011 대한기계학회 춘추학술대회 Vol.2011 No.10

The mechanical behavior of polymeric materials, HDPE depends on both time and temperature. The study of deformation behavior at different strain rates is important in engineering design such as X-band plate. Because mechanical properties and deformation mechanisms are strongly dependent on the applied strain rate. Generally the deformation behavior of polymeric materials based on engineering stress-strain curve is complex because of highly inhomogeneous nature of plastic deformation in particular necking. Therefore we tried to determine about mechanical behavior of HDPE in this study. Normally, tensile, compression, and impact testing under various strain rates of polymeric materials have been trying to determine the mechanical behavior. Since a method of tensile test is easy to test, so it is often used to evaluation of it. We performed tensile test by various strain rates(1 to 500%/min) in order to appreciate viscoelastic behavior on increasing strain rate. Tensile stress-strain curve was induced from the data and then we marked the point of transition to calculate transition stress, strain, and modulus.

귤 껍질과 고밀도폴리에틸렌(HDPE)의 혼합촉매열분해를 통한 방향족탄화수소의 생산

박영권 ( Young-kwon Park ),( Muhammad Zain Siddiqui ),강예진 ( Yejin Kang ),( Atsushi Watanabe ),이형원 ( Hyung Won Lee ),정상재 ( Sang Jae Jeong ),김승도 ( Seungdo Kim ),김영민 ( Young-min Kim ) 한국폐기물자원순환학회(구 한국폐기물학회) 2019 한국폐기물자원순환학회 심포지움 Vol.2019 No.1

고밀도폴리에틸렌을 귤껍질의 촉매열분해에 혼합열분해 시킨다. 사용되는 촉매는 HY와 HZSM-5로 각각 다른 기공과 산 세기 특성을 가지고 있다. 귤껍질은 비촉매 열분해와 촉매열분해의 질량분석결과(TG Analysis) 다른 점이 없었지만 고밀도폴리에틸렌은 촉매열분해를 했을 때 촉매효과로 분해온도가 HY의 경우 465℃에서 379℃까지 떨어졌고 HZSM-5의 경우 393℃까지 떨어졌다. 고밀도폴리에틸렌을 귤껍질과 혼합촉매열분해하면 분해온도가 HY의 경우 402℃까지 올랐고 HZSM-5의 경우 408℃까지 올랐다. 귤껍질과 고밀도폴리에틸렌의 Pyrolyzer-GC/MS의 결과 넓은 탄소범위를 가지는 산화물과 지방족탄화수소를 HY나 HZSM-5 촉매를 사용하여 효과적으로 방향족 탄화수소로 변형시켰다. HY를 이용한 귤껍질과 고밀도폴리에틸렌의 혼합촉매열분해에서 HZSM-5보다 큰 기공과 많은 양의 산점으로 더 많은 반응물을 생성할 수 있지만 HZSM-5를 이용한 결과 HZSM-5의 특징인 높은 산도와 형상선택성으로 HY보다 더 많은 방향족화합물을 생성 할 수 있다. 귤껍질과 고밀도폴리에틸렌의 혼합촉매열분해로 생성되는 방향족화합물은 예상했던 이론값보다 더 많은 양이 생성되었다. 이것은 귤껍질과 고밀도폴리에틸렌의 혼합촉매열분해를 했을 때 시너지효과가 있음을 시사한다. 사사: 이 논문은 2019년도 환경부의 폐자원에너지화특성화대학원사업(YL-WE-17-001)의 지원을 받아 수행되었습니다.