• Carbon letters
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• v.15 no.1
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• pp.50-56
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• 2014

We prepared ethylene vinyl alcohol (EVOH)/graphene oxide (GO) membranes by solution casting method. X-ray diffraction analysis showed that GOs were fully exfoliated in the EVOH/GO membrane. The glass transition temperatures of EVOH were increased by adding GOs into EVOH. The melting temperatures of EVOH/GO composites were decreased by adding GOs into EVOH, indicating that GOs may inhibit the crystallization of EVOH during non-isothermal crystallization. However, the equilibrium melting temperatures of EVOH were not changed by adding GOs into EVOH. The oxygen permeability of the EVOH/GO (0.3 wt%) film was reduced to 63% of that of pure EVOH film, with 84% light transmittance at 550 nm. The EVOH/GO membranes exhibited 100 times better (water vapor)/(oxygen) selectivity performance than pure EVOH membrane.

• Korean Membrane Journal
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• v.7 no.1
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• pp.19-27
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• 2005

PP hollow fiber membrane was hydrophilized by EVOH dip coating followed by low temperature plasma treatment and UV irradiation. EVOH coating attained high water flux without any prewetting but its stability did not guaranteed at high water permeation rate. At high water permeation rate, water flux declined gradually due to swelling and delamination of the EVOH coating layer causing pore blocking effect. However, plasma treatment reduces the swelling, which suppress delamination of the EVOH coating layer from PP support result in relieving the flux decline. Also, UV irradiation helped the crosslinking of the EVOH coating layer to enhance the performance at low water permeation rate. FT-IR and ESCA analyses reveal that EVOH dip coating performed homogeneously through not only membrane surface but also matrix. Thermogram of EVOH film modified plasma treatment and W irradiation show that crosslinking density of EVOH layer increased. Chemical modification by plasma treatment and UV irradiation stabilized the hydrophilic coating layer to increase the critical flux of the submerged membrane.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.1
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• pp.176-181
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• 2008

This paper was studied the possibility on the recycling of the scrap used as the food packaging materials, PP/EVOH/PP multilayer. Recycling study was investigated into thermal and mechanical properties of samples which were mixed PP/EVOH waste plastics scrap with two kinds of compatibilizers. Melt behaviors as thermal property and tensile strength, % strain at break point, and tensile modulus as mechanical properties were investigated into kinds of and the weight ratio of compatibilizers. Mixed PP/EVOH waste plastics shows compatibity when Minanto-s and GMS as compatibilizers are mixed 0.5wt.% over.

• Elastomers and Composites
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• v.49 no.3
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• pp.225-231
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• 2014

In this study, we used polypropylene grafted with itaconic acid (PP-g-IA) as a compatibilizer to prevent phase separation phenomenon which occurs upon blending polypropylene (PP) and ethylene-vinyl alcohol copolymer (EVOH). A compatibilizer was prepared using graft copolymerization of itaconic acid (IA) onto PP where input ratio of IA was 1, 2, 5, and 10 wt.%. To confirm the structure of PP-g-IA and the graft ratio of IA onto PP, we used $^1H$ NMR and FT-IR. We tested the compatibilizer which has highest graft ratio of 1% in immiscible PP/EVOH blends. The morphologies of PP/PP-g-IA/EVOH blends were analyzed by SEM. Thermal and mechanical properties of the blends were analyzed by DSC and UTM. PP-g-IA enhanced the interfacial adhesion of PP and EVOH copolymer.

• The Korean Journal of Rheology
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• v.1 no.1
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• pp.20-28
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• 1989

비닐 알코올의 함량이 62(EVOH-62) 및 71(EVOH-71) mole%인 에틸렌 비닐알코올 공중합체와 나일론(나일론-6, 나일론-6/12 및 나일론-12)과의 블렌드를 이축압출기에서 제 조하였으며 이들블렌드의 형택학 및 유변학적 성질을 SEM, TEM 및 RDS로 측정하였다. EVOH-61/나일론-6 및 EVOH-7/나일론-6 블렌드는 나일론의 조성이 많은 영역에서는 균 일상을 EVOH 조성이 많은 영역에서는 미세한 상분리(약 0.2$\mu$)를 나타내었다. 한편 EVOH-71/나일론-6/12 및 EVOH-71/나일론-12 블렌드는 상분리가 뚜렸하였으며 EVOH조 성이 많은 영역에서는 피브릴화가 나타났다. 낮은 진동주파수 영역에서 점도 대 조성곡선은 전반적으로 양의 편차를 보였으나 Cole-Cole plot은 나일론-6과의 블렌드가 나일론-6/12나 나일론-12와의 블렌드에 배해 유변학적인 측면에서보다 상용성이 우수함을보였다.

• Textile Coloration and Finishing
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• v.10 no.5
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• pp.19-23
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• 1998

In this study, Cellulose-Poly(Ethylene-Co-Vinyl Alcohol) (EVOH) fibers from MMNO(N-me-thylmorpholine-N-oxide) /water/cellulose/EVOH were prepared according to changes of EVOH content(wt％), which is main factors to dry-jet wet spinning. The mechanical properties and morphology of produced fibers were investigated. The resultant fibers had tensile strength of 3.7∼4.5g/d, elongation of 3.3∼7.5% and exhibited lower density than the density of pure cellulose fiber.

• Polymer(Korea)
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• v.24 no.6
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• pp.820-828
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• 2000

In this study, biaxially oriented film process was used to improve barrier property of polypropylene (PP)/ethylene-vinyl alcohol copolymer (EVOH) blends by inducing a laminar morphology of the dispersed phase in the matrix phase. In order to examine the extent of deformation during melt extrusion process, the rheological properties of the resins were measured and the viscosity ratio of the dispersed phase to the continuous phase was determined. The effects of compatibilizer content, draw ratio, and draw temperature on the oxygen permeability and morphology of biaxially drawn blend films were studied. The laminar morphology of the EVOH phase with a larger area of thinner layer induced by biaxial orientation was found to result in a significant increase in oxygen barrier property of PP/EVOH (85/15) blends by about 10 times relative to the pure PP When both PP-g-MAH and ionomer were used as the compatibilizers, there existed an optimum level of compatibilizer content for obtaining improved barrier properties with a well developed laminar structure. In addition, higher draw ratio and draw temperature were found to be more favorable processing conditions in obtaining higher barrier blends.

• Proceedings of the KAIS Fall Conference
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• 2006.11a
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• pp.283-286
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• 2006

식품 포장재로 사용되는 PP/EVOH/PP 다층 복합필름의 scrap 을 재활용하기 위한 기초연구로 상용화제 첨가한 PP/EVOH/Compatibilizer 블렌드의 상용화제 종류와 첨가량에 따른 재활용 수지의 열적 특성인 용융거동과 기계적 특성인 인장강도, 파단신률, 모듈러스 등의 특성을 조사하였다. 상용화제 Monato-s와 GMS를 각각 0.2, 0.5, 0.7 % 첨가한 블렌드 조성에서의 열적 특성과 기계적 특성을 확인한 결과 두 상용화제 모두 0.5 %이상의 조성 블렌드에서 PP/EVOH의 상용성을 얻을 수 있었다.

• Elastomers and Composites
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• v.50 no.3
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• pp.189-195
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• 2015

In this study, we prepared epoxidized poly ethylene-ter-1-decene-ter-divinylbenzene (Epo-PEHV) as a reactive compatibilizer to prevent phase separation phenomenon which occurs upon blending polypropylene (PP) and ethylene-vinyl alcohol copolymer (EVOH). Firstly, PEHV was prepared under high catalyst activity according to content of catalyst and cocatalyst. After then, we modified vinyl group of the terpolymer with epoxy group. We observed that the terpolymer was successfully epoxidized by 1H-NMR and FT-IR analysis. The Epo-PEHV was added by 2, 5, 10% in PP/EVOH blends. The morphologies and mechanical properties of PP/Epo-PEHV/EVOH blends were analyzed by SEM and UTM, respectively. Epo-PEHV enhanced the interfacial adhesion of PP and EVOH blends.

• The monthly packaging world
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• s.133
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• pp.104-109
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• 2004