• 한국전기전자재료학회논문지
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• 제14권11호
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• pp.941-946
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• 2001

The fundamental study on HTV silicone for insulation material has been performed. In order to estimate the chemical behavior of siloxane under high voltage, H-NMR, GPC and vinyl contents measurement were used. As an experimental results, after high voltage stress, the molecular weight of siloxane are increased, the vinyl contents of siloxane are decreased. The dielectric strength of vinyl group containing siloxane was lower than only methyl containing siloxane.

• Elastomers and Composites
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• 제50권1호
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• pp.18-23
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• 2015

Vinyl acetate (VA) contents of poly(ethylene-co-vinyl acetate) (EVA) analyzed by infrared spectroscopy (IR), nuclear magnetic spectroscopy (NMR), and thermogravimetric analysis (TGA) were compared. Four grade EVAs supplied by Aldrich Co. and four grade EVAs manufactured by DuPont Co. were used. For IR analysis, VA contents were determined using calibration curve (absorbance ratio of $1739cm^{-1}/2922cm^{-1}$ or $609cm^{-1}/1464cm^{-1}$) of reference EVAs. Correlation coefficients of the calibration curves were not sufficiently high ($r^2{\leq}0.96$). For NMR analysis, VA contents were determined using peaks of $CH_3$, $CH_2$, and CH. VA contents determined by NMR analysis were less than those marked by suppliers more than 10%. For TGA, VA contents were determined using weight loss through deacetylation. VA contents determined by TGA were slightly different with those marked by suppliers. Difference in the VA contents determined by different analytical methods was discussed, and difference in the analytical results according to the EVA suppliers was also examined.

• 한국자기공명학회논문지
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• 제7권2호
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• pp.68-73
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• 2003

Proton magic angle spinning spectra and thermogravimetric analysis data of poly(vinyl butylal) with water in it indicate water contents in the poly(vinyl butylal) samples were reduced during magic angle spinning. Our observation implies that the centrifugal force on the samples due to magic angle spinning cannot be neglected, especially on inhomogeneous and soft samples like poly(vinyl butylal) we tested in this work.

• 방사선산업학회지
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• 제4권1호
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• pp.19-23
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• 2010

Vinyl ester (VE) resins, introduced in the late 1960s, have made large strides in reinforced plastics applications as adhesive and matrix materials on their appropriate mechanical performance characteristics in the glassy state. Generally, VE resins are a group of dimethacrylate resins based on bisphenol A type epoxy resin. They exhibit easy handling properties as well as good resistance to most chemical agents due to their mechanical and thermal properties. In this study, the effects of curing methods of vinyl ester resins on gel contents, flexural strength and dynamic mechanical properties were investigated. Thermal curing (room temperature, $80^{\circ}C$) and electron beam curing were used to crosslink a VE resin/styrene complex (65/35 wt%) with methyl ethyl ketone peroxide (MEKPO) as a catalyst and an 8 wt% cobalt naphthenate in styrene solution as a accelerator. For the samples, gel contents as well as flexural strength and dynamic mechanical properties were characterized and compared by soxhlet apparatus, universal testing machine (UTM) and dynamic mechanical analysis (DMA). As a result, the electron-cured VE resin was confirmed as a better condition than those for gel contents, flexural strength and dynamic mechanical properties, respectively.

• Elastomers and Composites
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• 제34권4호
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• pp.360-365
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• 1999

2-에틸헥실아크릴레이트(2-EHA), n-부틸아크릴레이트(BA), 에틸아크릴레이트(EA) 및 비닐아세테이트(VAc)의 네 가지 단량체를 사용하여 제조한 아크릴4원공중합체(PEBEV)와 염화비닐-비닐프로피오네이트 공중합체 (PVCVP)를 용액 블렌드하고 이들의 점착물성을 조사하여 PEBEV/염화비닐-비닐아세테이트 공중합체(PVCVAc) 블렌드계와 비교하였다. 블렌드계의 상용성은 PEBEV/PVCVP계가 PEBEV/PVCVAc계 보다 우수하였다. 블렌드계의 점착성은 두계 모두 비슷하였으나, 유지력의 경우 PEBEV/PVCVAc계는 PVCVAc 함량이 15%를 넘어서면서 감소하는데 반해 PEBEV/PVCVP계는 PVCVP 함량이 증가할수록 계속 증가하는 경향을 보여주었다. 박리 유형을 살펴보면, PEBEV/PVCVP 블렌드계중 PVCVP의 함량이 5%인 블렌드가 부분응집파괴 형태를 보이는 것을 제외하면, 모든 블렌드계가 계면파괴의 형태를 보였다.

• 한국초지조사료학회지
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• 제13권3호
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• pp.228-233
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• 1993

Method for the sun curing dehydration of pig excreta by using vinyl house was described. We determined effects of the dehydrated pig excreta on the yields of whole crop corn and proximate chemical composition of whole crop corn. Pig excreta were dehydrated upto 15% of moisture content by the 3-4 days of sun curing dehydration in vinyl house in the summer period. There was no significant difference between the dehydrated pig excreta treatment and the chemical fertilizer treatment on dry matter(DM) content, DM yield and crude protein contents of whole crop corn. Ca and Mg contents by the dehydrated pig excreta treatment were lower than those by thechemical fertilizer treatment. In the contrast, K content by the dehydrated pig excreta treatment was higher than those by the chemical fertilizer treatment. and dehydrated pig excreta treatments were higher in K/Ca+Mg ratio than chemical fertilizer treatment. These results suggested the availability of the sun curing dehydration of pig excreta in vinyl house in small-scale animal industry. In addition, the dehydrated pig excreta treatment showen similar effects to the chemical fertilizer treatment on dry matter yields and contents of chemical composition of whole crop corn. These results suggest that using the sun curing dehydration of pig excreta could reduce the chemical fertilizer cost. However, we need more study to the relationship between the unbalanced mineral contents and animal health.

• Korean Membrane Journal
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• 제6권1호
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• pp.24-29
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• 2004

Poly(vinyl alcohol)(PVA) and hyaluronic acid(HA) hydrogel membranes were prepared with varying HA contents from 10 to 50 wt% of PVA. The water contents of the resulting PVA-HA hydrogel membranes in various pH conditions were measured. And the permeation coefficient of indomethacin was determined using several PVA-HA hydrogel membranes at various pH conditions and also 37$^{\circ}C$.

• 반도체디스플레이기술학회지
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• 제18권1호
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• pp.42-47
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• 2019

The four different polymer compounds were manufactured to make cable sheath for ship industry. Two kinds of ethylene-vinyl acetate (EVA) were selected as main matrix polymers for compounding with fire retardant, crosslinking agent, filler, plasticizer, and other additives. The properties of the four compounded materials were investigated with the contents of fire retardant, silane coated aluminum hydroxide (S-ATH). Rheology, Mooney viscosity, and tensile strength increased with S-ATH contents by reinforcing effect. With increasing fire retardant amount, fire resistance increased, but cold resistance didn't show an obvious enhancement due to polar effect of vinyl acetate in EVA.

• Elastomers and Composites
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• 제54권2호
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• pp.118-122
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• 2019

Four different polymer compounds were manufactured to make cable sheaths for the shipping industry. Two kinds of ethylene vinyl acetate (EVA) as the main matrix polymers and EVA-grafted maleic anhydride (EVA-g-MAH) as the coupling agent were selected for compounding with fire retardant, crosslinking agent, filler, plasticizer, and other additives. The properties of the four compounded materials were investigated with different contents of the fire retardant, silanecoated magnesium dihydroxide (S-MDH). In the rheology evaluation, the $t_{60}$ and ${\Delta}T$ values increased with increasing S-MDH contents. On the other hand, the tensile strength decreased with increasing S-MDH content due to a relative decrease in binder polymers. With increasing S-MDH content, fire resistance increased, but cold resistance showed no obvious enhancement due to the polar effect of vinyl acetate in EVA.

• 폴리머
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• 제27권5호
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• pp.429-435
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• 2003

양이온η$^3$-알릴 팔라듐 촉매를 사용하여 환상형 올레핀 단량체인 노보넨 (NB)과 5-비닐-2-노보넨(VNB)을 조성별로 비닐 부가 공중합하였다. 공중합체는 고수율과 고분자량 (M$_{w}$ > 760000)으로 얻을 수 있었다. VNB 함량이 많아질수록 공중합체의 분자량과 수득율은 감소하였으며, 첨가한 공단량체의 양과 공중합한 후 함유된 단량체의 양이 비례함을 FT-IR 분광분석으로 확인하였다. $^1$H-NMR 분석 결과 VNB는 exo, endo 이성체 모두 중합에 참여하는 것을 알 수 있었다. NB-VNB 공중합체의 분해 개시 온도는 약 300 $^{\circ}C$이었고, 열안정성은 VNB 함량과 관계없이 유사한 거동을 나타내었다. 합성된 NB-VNB 공중합체의 곁사슬 비닐기는 m-CPBA를 이용하여 에폭시화 하였고, 또한 9-BBN을 이용하여 수산화기를 도입하였다. 조성별 공중합체에 각각의 치환기가 도입된 것은 FT-IR, $^1$H-NMR 분석으로 확인하였다..