Hexamethyldisiloxane의 放射效果에 關한 硏究

孟琦錫 충남대학교 공업기술개발연구소 1976 工業技術開發硏究所論文集 Vol.3 No.1

The irradiation chemistry of hexamethyldisiloxane has been studied in detail and product yields have been established for both gaseous and liquid products. Significant differences from previously reported values, most notably in the methane and in low and intermediate molecular weight liquid product, were found. A materials balance is attempted and the products found are rationalized on the basis of fragmentation patterns found in mass spectrometric studies. The new G values are sufficiently different from previous report to have completely justified this investigation. More so in view of the fact that the present data are to be used as the standard for later investigation.

탄소섬유와 Epoxy resin 간의 계면결합력 증가를 탄소섬유의 양극산화

맹기석,박정기,주혁종,황택성,박병재 한국고분자학회 1989 한국고분자학회 학술대회 연구논문 초록집 Vol.1989 No.10

기술인력 개발과 산업체의 역할

맹기석 한국고분자학회 1981 폴리머 Vol.5 No.6

Atactic Polypropylene에 대한 염회비닐의 그라프트 중합

황택성,민병철,맹기석 忠南大學校 産業技術硏究所 1987 산업기술연구논문집 Vol.2 No.2

Atactic Polypropylene, a byproduct obtained in the manufacture of isotatic polypropylene, has been synthesed under various reaction conditions. In this study, suspension graft polymerizations of Vinylchloride onto Atatic polypropylene were carried out in aqueous with benzoyl peroxide as initiator. The effect on the grafting efficiency and reaction rate was observed by varing APP concentration Also, reactivity onto each hydrogen is the most good tertiary hydrogen among primary, secondary and tertiary. If the vinyl chloride concentration contains small in the polymerization, graftmer have carbonyl group, abnomal structure.

PVC 및 Olefin계 Copolymer의 열안정성에 관한 연구(Ⅰ) : 제조 및 내열성 Preparation and Heat Resistance

맹기석,송해영,박인환,황택성,민병철 충남대학교 공업교육연구소 1986 論文集 Vol.9 No.1

In order to improve the heat stability of poly(vinyl chloride), copolymerization of PVC and olefin was performed and the thermal properties of the copolymer was investigated. PVC-olefin copolymers with various olefin contents were prepared by a typical suspension polymerization method at 50℃. It was found that both the degree of conversion and molecular weight decreased as the comonomer ratio (olefin/VCM) in the copolymer was increased. Thermal analysis showed the higher content of olefin reduced the glass transition temperature(Tg) of the copolymer while the heat stability of the copolymer remained almost unchanged in terms of the initial decomposition temperature which is about the same as that of homo PVC. On the other hand, TGA analysis showed that the weight loss became smaller as the comonomer ratios of olefin was increased even though the molecular weight of the copolymer is lower. The polyene sequence distribution in the copolymer degraded at 120℃ was studied by UV-visible spectroscopy. It showed a trend that the amount of long polyene sequence increases at first as the comonomer ratio is increased, however a further increase of the comonomer ratio reverses the trend such that the short polyene sequence is more frequently found.

동위원소의 이온교환수지에 의한 분리 : 다공성이온교환수지(P-SSTDVB)의 합성과 리튬동위원소 분리에 관한 연구

맹기석,송해영,주혁종,황명천,김환영,류해일,서무열,김동원 충남대학교 공업교육연구소 1982 論文集 Vol.5 No.1

Suspension copolymerization of the styrene with divinylbenzene initiated by benzoylperoxide was carried out in presence of water and sodium chloride at 90℃. We used the toluene and heptance as diluents making the pore of the ion exchanger. Porous ion exchanger, sulfonated styrene-divinylbenzene was prepared by sulfonating porous styrenedivinylbenzene copolymer with cone-sulfuric acid and chlorosulfonic acid. A sulfonic acid group of sulfonated styrene-divinylbenzene copolymer was identified by means of infrared absorption spectroscopy. The pore volume of the styrene-divinylbenzene copolymer are increased as the mole fraction of the diluents and the contents of divinylbenzene, and then after it was sulfonated, the pore volume are decreased. Adsorption of metal ion for porous ion exchanger are also investigated. The distribution coefficients of various metal ions (Cr, Cd, Hg, Pb) for the porous styrene-divinylbenzene ion exchanger appears to give greater values than Dowex 50W-X8 ion exchanger. The cation-exchange resin employed were Dowex 50W-X8, 100∼200mesh and synthetic PSSTDVB(8%), 50∼200mesh, the eluents was a mole of hydrochloric acid. When used Dowex 50W-X8 and P-SSTDVB, respectively, it's isotope separation factor for lithium calculated from the isotope composition of the eluted fractions were 1.0011 and 1.0020.

석탄유동층 연소로에서의 Freeboard 연소특성 : 2 . 수학적 모델링 2 . Mathematical Modelling

맹기석,박영성,손재익,김영성 한국화학공학회 1994 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.32 No.1

국내 무연탄을 대상으로 하는 유동층 연소로에 있어서 freeboard에서 일어나는 탄소연소반응을 해석하기 위해 연소로내 탄소비산구조를 설정하고 관련된 reaction kinetics를 적용하여 freeboard 탄소연소반응의 수식모델을 전개하였다. 모델의 해석을 통해 산출된 탄소연소율, 가스농도분포 및 온도분포 등의 freeboard 탄소연소반응의 주요 특성치는 실험치와 비교적 근사한 일치를 보였으며, 모델에 적용된 kinetic parameter중 탄소연소반응의 표면반응속도상수는 freeboard내 온도 및 가스조성에 커다란 영향을 주며 CO 재연소반응속도상수는 CO 농도분포에 지배적인 영향을 주는 것으로 나타났다. A mathematical model for the carbon combustion reaction in the freeboard of a fluidized bed combustor using domestic anthracite coal was developed by using the entrainment mechanism of unburned carbon particle and applying the related reaction kinetics. The extent of carbon combustion, gas composition and temperature distributions in the freeboard can be determined from the proposed model. It was also found that among the kinetic parameters, the surface reaction rate constant gives significant effects on the temperature and gas compositions in the freeboard, while the CO combustion reaction rate constant gives a dominant effect on CO composition in the freeboard.

o-Aminophenol 誘導體 및 4-Vinyl Pyridine 系 이온 交換體의 合成과 그의 特性에 關한 硏究

宋海永,孟琦錫 圓光大學校 1979 論文集 Vol.13 No.2

o-Hydroxyphenyl amino acetic acid-phenol-formaldehyde resin was prepared by treating o-hydroxyphenyl amino acetic acid with phenol and formaline in presence of sodium hydroxide, Radical copolymerization of the complexed 4-vinyl pyridine with styrene and divinyl benzene initiated by azobisisobutyronitrile was carried out in N,N-dimethylforamide(DMF) in presence of baruim chloride at 98℃. In the preparation of o-hydroxy phenyl amino acetic acid pheno-formalde hyde resinand 4-vinyl pyridine-styrene-divinyl benzene copolymer were also found the optimum reaction condition. Ion exch anger, sulfonated 4-viniyl pyridine-styrene-divinybenene was prepared by solfonating 4-vinyl pyridine-styrene-divinyl benzene copolymer with conc-sulfuric acid and chloro sulfuric scid. The compositions of synthetic resins were analyzed by infrared absorption spectroscopy and also discussed. Ion exch anger, o-hydroxy phenyl amino acetic acid -phenol-formaldehyde resin, has been show to having an ion exchange capacity up to 4.68meq/g, and 4-vinylpyyridine -styrene-divinylbenzene copolymer posseses a total exchange capacity of 7.82 meq/g. Adsorption of metal ion for ion exchanger are also investigated. Cation exchange distributio coefficient with Dowex 50w-x8 and sulfonated 4-vinyl pyridine-styrene-divinylbenzene copolymer are presented for 6 elements, Cr(Ⅲ), Mn(Ⅱ), Cu(Ⅱ), Mg(Ⅱ)and Co(Ⅱ), inhydrochloric-succinic acid and acetone media. The determination of the distribution coefficient was carried out in 0.05∼9M hydrochloric acid solutions containing 0-95% of the organic solvents succinic acid and acetone. Based on these distribution data, possibilities for for separations are demonstrated by elution curve for multi compound system Cr(Ⅲ)-Mn(Ⅱ)-Cu(Ⅱ) and Mg(Ⅱ)-Cd(Ⅱ)-Co(Ⅱ). The swelling properties and electric resistance for sulfonated 4-vinyl pyridine-styrene-divinylbenzene ion exchage memberanes prepared by treating sulfonated 4-vinyl pyridine-styrene-divinyl benezene copolymer with polyethylene are inivestigated and also discussed.

Methylene-bis-salicylaldehyde 誘導體 合成과 反應速度에 관한 硏究

孟琦錫,김공수,宋海永 충남대학교 1977 工業技術開發硏究所論文集 Vol.4 No.2

Optimum conditions and reaction rates of synthesis of derivatives of methylene-bis-salicyl aldehyde from salicyl aldehyde and nitro salicyl aldehyde are as follows. a) In the synthesis 5,5'-methylene-bis-salicyl aldehyde, it is possible to get more then 40 percentages of yield at the 95℃ reaction temperature and more then 10 hrs reaction. b) In the synthesis of 3,3'-methylene-5,5'-dinitro-bis-salicyl aldehyde and 5,5'-methylene-3,3'-dinitro-bis-salicyl aldehyde it is possible to get more then 70 percentages of yield at 70℃ reaction temperature and one hour reaction.

폴리비닐 슬폰산-디비닐벤젠의 합성과 이온교환성질에 관한 연구

서구원,윤종태,맹기석 忠南大學校 産業技術硏究所 1988 산업기술연구논문집 Vol.3 No.1

Radical copolymerization of the complexed vinylacetate-divinyl benzene initiated by azobisisobutyronitrile was carried out in toluene at 98℃ for 7hours. Polyvinylalcohol-divinylbenzene resin was prepared by transesterificating vinylacetate-divinylbenzene copolymer with a 1% methanolic sodium hydroxide solution. Sulfonated polyvinylalcohol-divinylbenzene(SPALDVB) was prepared by sulfonating vinylalcohol-divinylbenzene resin with conc-sulfuric acid. The composition of each synthetic resin were identified by means of infrared adsorption spectroscopy. 1) SPVALDVB possess exchange capacity of 7.8 meq/g. 2) Adsorption of SPVALDVB were increased when pH is increased. 3) The determination of the distribution coefficient was carried out in 0.1-1.0 N hydrochloric acid solution containing 20-90% of the ethanol, ethylene-glycol. Increasing hydrochloric acid concentration, Kd is decreased. 4) The separation of Co(Ⅱ), Ni(Ⅱ), Cd(Ⅱ)ion is possible in 40% ethanol with 0.5N hydrochloric acid mixture.