• 제목/요약/키워드: MODIFIED POLYETHYLENE

검색결과 190건 처리시간 0.05초

상용화제의 종류가 선형 PPS/PET 블렌드의 물성에 미치는 영향 (Effect of Compatibilizer Types on the Properties of Linear PPS/PET Blends)

  • 김성기;홍인권;이상묵
    • 폴리머
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    • 제37권4호
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    • pp.500-506
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    • 2013
  • 비혼화성인 선형의 폴리페닐렌설파이드(PPS)와 상용 폴리에틸렌테레프탈레이트(PET)의 블렌드 물성에 미치는 상용화제의 구조에 따른 영향을 조사하였다. 머독 혼련 스크류가 장착된 단축 압출기를 통하여 제조한 블렌드를 성형하여 그 특성들을 살펴보았다. 물성과 경제성을 고려하여 PPS/PET(40/60)을 기초 블렌드로 선정한 후 여기에 도메인 크기감소와 계면접착력 향상을 위하여 상용화제로 styrene-ethylene/butylene-styrene(SEBS), modified SEBS(m-SEBS), modified polystyrene(m-PS) 등을 사용하였다. 이들을 기초블렌드에 첨가하여 삼원블렌드를 제조한 후 열적, 유변학적, 기계적 특성을 측정하고 모폴로지를 관찰하였다. 기계적 물성은 각각 m-SEBS와 m-PS 첨가량 1 phr 부근에서 최대값을 보였는데 그 값이 이론적인 혼화성계의 값에 거의 근접하였으며 m-PS가 가장 뛰어난 성능을 보였다. m-SEBS와 m-PS는 선형 PPS와/또는 PET와의 부분적인 반응을 통해 상용성을 증대시켜서 더 큰 효과를 보인 것으로 판단된다. 이러한 삼원블렌드는 경제성있는 PPS 알로이로서 적용이 가능하리라 사료된다.

Polyethylene Film Surface Metallization Modified by Radiation Grafting of N-vinyl Pyrollidone

  • Aal, A.A.;Khutoryanskiy, V.V.;Nurkeeva, Z.S.;Mun, G.A.;Soh, D.W.
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2004년도 SMICS 2004 International Symposium on Maritime and Communication Sciences
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    • pp.110-112
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    • 2004
  • Poyethylene films can be modified by radiation grafting of N-vinyl pyrollidone using y-radiation. FTIR spectra were used to confirm the modification of PE films. The modified films were activated by two-step and one step methods for electroless Cu plating. Morphology of metallized films has been investigated. Electroless Cu plating onto the modified films depends mainly on the grafting degree and activation type. The conductivity of the metallized films has been investigated.

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개질된 탄소나노튜브/하이드로겔 복합막의 기체 투과 특성 (Gas Transport Behavior of Modified Carbon Nanotubes/Hydrogel Composite Membranes)

  • 윤희욱;이희대;박호범
    • 멤브레인
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    • 제23권5호
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    • pp.375-383
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    • 2013
  • 나노 소재는 표면적이 매우 크고 크기나 기공이 균일하여 분리막에서 물질 전달통로나 특수한 기능성을 갖게 하는 소재로 이용이 가능하다. 그중에서도, 그래핀, 그래핀 옥사이드 및 탄소나노튜브와 같은 나노탄소 구조체에 대한 연구가 활발히 이루어지고 있다. 일차원 구조를 갖는 탄소나노튜브의 경우 우수한 열적, 화학적 및 기계적 성질을 가지고 있으나, 기존 연구에서는 주로 고분자와 혼합하여 기계적 물성을 강화하는 복합소재로서 사용됐으며, 응용분야의 한계를 가지고 있었다. 본 연구에서는 폴리 에틸렌 글리콜 다이아크릴레이트(PEGDA) 고분자 내에 개질된 탄소나노튜브를 혼합하여, 기체 분리막에서의 투과도 및 선택도의 변화를 관찰하였다.

Rheology of flocculated kaolinite dispersions

  • McFarlane A.J.;Addai-Mensah J.;Bremmell K.
    • Korea-Australia Rheology Journal
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    • 제17권4호
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    • pp.181-190
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    • 2005
  • Rheological characterisation of flocculated kaolinite pulps has been undertaken to elucidate particle interactions underpinning the dewatering behaviour induced by flocculation with polyethylene oxide (PEO), anionic polyacrylamide (PAM A) and their blends. Shear yield stress $(\tau_y)$ analysis indicated that polymer mediated particle interactions were markedly amplified upon shear of PEG based pulps. In contrast, PAM A based pulps showed a significant decrease in yield values upon shear. Steady stress measurements analysed using a modified Ellis model indicated subtle differences between the respective linear viscoelastic plateaus of the pulps. Furthermore, modified shear thinning behaviour was evident in PEG based pulps. Estimation of elastic and viscous moduli (G', G') was made using dynamic stress analysis for comparison with values determined from vane measurements. Despite a noticeable difference in the magnitude of G' between the two methods, similar trends indicating sheared PEG-based pulps to be more elastic than PAM based pulps, were observed. Floc microstructural observations obtained in support of rheological properties indicate that PEG flocculant induces significantly more compact particle aggregation within the clay pulps under shear consistent with the yield stress data, in contrast to PAM A, or indeed unsheared PEG based pulps. Consequentially, sheared PEG based pulps show significantly improved dewatering behaviour. The implications of the results, potential benefits and drawbacks of flocculation with PEG and PAM A are discussed with respect to improvements in current dewatering processes used in the minerals industry.

Surface Modification and Fibrovascular Ingrowth of Porous Polyethylene Anophthalmic Implants

  • Yang, Hee-Seok;Park, Kwi-Deok;Son, Jun-Sik;Kim, Jae-Jin;Han, Dong-Keun;Park, Byung-Woo;Baek, Se-Hyun
    • Macromolecular Research
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    • 제15권3호
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    • pp.256-262
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    • 2007
  • The purpose of this study was to determine the effect of surface modification on the fibrovascular ingrowth into porous polyethylene (PE) spheres ($Medpor^{(R)}$), which are used as an anophthalmic socket implant material. To make the inert, hydrophobic PE surface hydrophilic, nonporous PE film and porous PE spheres were subjected to plasma treatment and in situ acrylic acid (AA) grafting followed by the immobilization of arginine-glycine-aspartic acid (RGD) peptide. The surface-modified PE was evaluated by performing surface analyses and tested for fibroblast adhesion and proliferation in vitro. In addition, the porous PE implants were inserted for up to 3 weeks in the abdominal area of rabbits and, after their retrieval, the level of fibrovascular ingrowth within the implants was assessed in vivo. As compared to the unmodified PE control, a significant increase in the hydrophilicity of both the AA-grafted (PE-g-PAA) and RGD-immobilized PE (PE-g-RGD) was observed by the measurement of the water contact angle. The cell adhesion at 72 h was most notable in the PE-g-RGD, followed by the PE-g-PAA and PE control. There was no significant difference between the two modified surfaces. When the cross-sectional area of tissue ingrowth in vivo was evaluated, the area of fibrovascularization was the largest with PE-g-RGD. The results of immunostaining of CD31, which is indicative of the degree of vascularization, showed that the RGD-immobilized surface could elicit more widespread fibrovascularization within the porous PE implants. This work demonstrates that the present surface modifications, viz. hydrophilic AA grafting and RGD peptide immobilization, can be very effective in inducing fibrovascular ingrowth into porous PE implants.

Improvement of Shelf-life and Quality in Fresh-Cut Tomato Slices:

  • Hong Ji Heun
    • 한국식품저장유통학회:학술대회논문집
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    • 한국식품저장유통학회 2004년도 총회및 심포지움
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    • pp.67-72
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    • 2004
  • Quality of fresh-cut tomato slices was compared during cold storage under various modified atmosphere packaging conditions. Chilling injury of slices in containers sealed with Film A was higher than with Film B; these films had oxygen transmission rates of 87.4 and 60.0 ml $h^{-1}\;m^{-2}\;atm^{-1}$ at $5^{\circ}C\;and\;99\%$ RH, respectively. While slices in containers with an initial atmospheric composition of air, $4\%\;CO_2+1\;or\;20\%\;O_2,\;8\%\;CO_2+1\;or\;20\%\;O_2,\;or\;12\%\;CO_2+20\%\;O_2$ showed fungal growth, slices in containers with $12\%\;CO_2+1\%\;O_2$ did not. Low ethylene in containers enhanced chilling injury. Modified atmosphere packaging provided good quality tomato slices with a shelf-life of 2 weeks or more at $5^{\circ}C$. Experiments were conducted to compare changes in quality of slices of red tomato (Lycopersicon esculentum Mill. 'Sunbeam') fruit from plants grown using black polyethylene or hairy vetch mulches under various foliar disease management systems including: no fungicide applications (NF), a disease forecasting model (Tom-Cast), and weekly fungicide applications (WF), during storage at $5^{\circ}C$ under a modified atmosphere. Slices were analyzed for firmness, soluble solids content (SSC), titratable acidity (TA), pH, electrolyte leakage, fungi, yeasts, and chilling injury. With both NF and Tom-Cast fungicide treatments, slices from tomato fruit grown with hairy vetch (Vicia villosa Roth) mulch were firmer than those from tomato fruit grown with black polyethylene mulch after 12 days storage. Ethylene production of slices from fruit grown using hairy vetch mulch under Tom-Cast was about 1.5- and 5-fold higher than that of slices from WF and NF fungicide treatments after 12 days, respectively. The percentage of water-soaked areas (chilling injury) for slices from tomato fruit grown using black polyethylene mulch under NF was over 7-fold that of slices from tomato fruit grown using hairy vetch under Tom-Cast. When stored at $20^{\circ}C$, slices from light-red tomato fruit grown with black polyethylene or hairy vetch mulches both showed a rapid increase in electrolyte leakage beginning 6 hours after slicing. However, slices from tomato fruit grown using the hairy vetch mulch tended to have lower electrolyte leakage than those grown with black polyethylene mulch. These results suggest that tomato fruit from plants grown using hairy vetch mulch may be more suitable for fresh-cut slices than those grown using black polyethylene mulch. Also, use of the disease forecasting model Tom-Cast, which can result in lower fungicide application than is currently used commercially, resulted in high quality fruit for fresh-cut processing. Experiments were conducted to determine if ethylene influences chilling injury, as measured by percentage of slices exhibiting water-soaked areas in fresh-cut tomato slices of 'Mountain Pride' and 'Sunbeam' tomato (Lycopersicon esculentum Mill.). Ethylene concentration in containers without ventilation significantly increased during storage at $5^{\circ}C$, whereas little or no accumulation of ethylene occurred in containers with one or six perforations. Chilling injury was greatest for slices in containers with six perforations, compared to slices in containers with one perforation, and was over 13-fold greater than that of slices in control containers with no perforations. An experiment was also performed to investigate the effectiveness of including an ethylene absorbent pad in containers on subsequent ethylene accumulation and chilling injury. While ethylene in the no-pad controls increased continually during storage of both 'Mountain Pride' and 'Sunbeam' tomatoes at $5^{\circ}C$ under modified atmosphere conditions, no increase in accumulation of ethylene was observed in containers containing ethylene absorbent pads throughout storage. The ethylene absorbent pad treatment resulted in a significantly higher percentage of chilling injury compared with the no-pad control. In studies aimed at inhibiting ethylene production using AVG during storage of slices, the concentration of ethylene in control containers (no AVG) remained at elevated levels throughout storage, compared to containers with slices treated with AVG. Chilling injury in slices treated with AVG was 5-fold greater than that of controls. Further, we tested the effect of ethylene pretreatment of slices on subsequent slice shelf-life and quality. In slices treated with ethylene (0, 0.1, 1, or $10\;{mu}L\;L^{-1}$) immediately after slicing, ethylene production in non-treated controls was greater than that of all other ethylene pre-treatments. However, pretreatment of slices 3 days after slicing resulted in a different pattern of ethylene production during storage. Ihe rate of ethylene production by slices treated with 1 L $L^{-1}$ ethylene 3 days after slicing was greater during storage than any of the other ethylene treatments. With slices pre-treated with ethylene, both immediately and 3 days after slicing, the rate of ethylene production tended to show an negative correlation with chilling injury. Chemical name used: 1-aminoethoxyvinylglycine (AVG).

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Eu-PEG로 구성된 상변환 발광재료의 합성 및 물성에 대한 연구 (Study of Synthesis and Property of Eu-PEG Phase Change Luminescent Materials)

  • Gu, Xiao-Hua;Xi, Peng;Shen, Xin-Yuan;Cheng, Bo-Wen
    • 폴리머
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    • 제32권4호
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    • pp.305-312
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    • 2008
  • A novel TPC-PEG-TPC with active end-groups was obtained from the end-groups of polyethylene glycol (PEG) modified by terephthaloyl chloride (TPC). These active end-groups can link up with a rare earth ion, which is a luminescent center of a rare earth fluorescent complex. Complexes of Eu-PEG with novel ligands (TPC-PEG-PTC) were synthesized by the coordination of the active reactant (as the first ligand) and phenanthroline (as the second ligand) with $Eu^{3+}$.IR, $^1H$-NMR, element analysis, DSC, WAXD, fluorescent spectroscopy, TGA, and SEM were used to characterize the structure and properties of these complexes. The results showed that this type of complex is a heat storage material with the phase change character of polyethylene glycol (PEG) and the luminescent properties of europium. There was no thermal decomposition of the complex of Eu-PEG until $300^{\circ}C$. SEM showed that the complex of Eu-PEG can be dispersed in PE.

Crack Layer 이론을 이용한 배관용 고밀도 폴리에틸렌의 응력부식균열 진전 및 수명 예측 모델 (Modeling of stress corrosion crack growth and lifetime of pipe grade high density polyethylene by using crack layer theory)

  • 위정욱;최병호
    • 한국압력기기공학회 논문집
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    • 제11권2호
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    • pp.45-50
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    • 2015
  • In many cases, the field fracture mechanism of the thermoplastic pipe is considered as either brittle or environmental fractures. Thus the estimation of the lifetime by modeling slow crack growth considering such fracture mechanisms is required. In comparison of the some conventional and empirical equations to explain the slow crack growth rate such as the Paris' law, the crack layer theory can be used to simulate the crack and process zone growth behaviors precisely, so the lifetime of thermoplastic pipe can also be accurately estimated. In this study, the modified crack layer theory for the stress corrosion cracking (SCC) of high density polyethylene is introduced with detailed algorithm. The oxidation induction time of the HDPE is also considered for the reduction of specific fracture energy during exposed to chemical environments. Furthermore, the parametric study for an important SCC parameter is conducted to understand the slow crack growth behavior of SCC.

지방산과 폴리에틸렌글리콜의 혼합에 따른 수용성 절삭유제의 절삭특성 (Drilling Properties of Water-Based Metal Working Fluid Containing Fatty Acid and Polyethylene Glycol)

  • 김영운;정근우;윤유정;김세훈;강석춘
    • 한국정밀공학회지
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    • 제18권2호
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    • pp.161-170
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    • 2001
  • Synthetic water-based metal-cutting fluids are increasingly popular in the metal-working industry because of its environmental friendliness. The propose of this study is to investigate the synergistic effect of combining polyethylene glycol and common fatty acid in formulating a metal-cutting fluid. The tested metals were aluminum, copper and steel, and the test was performed with a modified drilling machine. From the study, it was found that there existed some synergistic effects on the drilling efficiency of the metals to decrease of cutting time, cutting energy, torque as well as the smoothness of surface depended on the formulation ratio of the two fluids.

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