Poly ( Acrylonitrile - EPDM - 4 - Chlorostyrene ) 과 스티렌공중합체의 합성과 열분해에 관한 연구

김동건,신봉섭,하창식,설수덕 ( Dong Keun Kim,Bong Sub Shin,Chang Sik Ha,Soo Duk Seul ) 한국화학공학회 1992 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.30 No.6

The graft copolymer of 4-chlorostyrene and acrylonitrile onto ethylene-propylene-diene terpolymer(EPDM) was synthesized with benzoyl peroxide(BPO) as an initiator at 70℃. The maximum grafting efficiency was 76% when tetrahydrofuran(THF) was used as a solvent. The thermal degradation, flame retardancy, light resistance and weatherability of AECS were compared with those of Poly(acrylonitrile-butadienestyrene) (ABS), Poly(α-methylstyrene-acrylonitrile) (α-SAN), Poly(acrylonitrile-EPDM-styrene) (AES). The activation energies of thermal degradation determined by thermogravimetry(TGA) and differential scanning colorimetry(DSC) were in the order of AECS(49-51 ㎉/㏖)>AES(46-50 ㎉/㏖)>α-SAN(45-49 ㎉/㏖)>ABS(44-46 ㎉/㏖). The light resistance and weatherability were in the order of AES>AECS>α-SAN>ABS. The thermal degradation of AECS was considered to happen by main chain scission at an environment temperature below 400℃.

Poly ( Alkyl Methacrylate ) 와 Tetrabromobisphenol - A ( TBBA ) Blend 의 열분해에 관한 연구

김동건,신봉섭,설수덕,손진언 ( Dong Keun Kim,Bong Sub Shin,Soo Duk Seul,Jin Eon Sohn ) 한국화학공학회 1991 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.29 No.6

The thermal degradation behavior of poly(alkyl methacrylate) and flame-retardant, tetrabromobisphenol-A(TBBA) mixture was analyzed using the Gel Permeation Chromatography(GPC), Infra-red Spectroscopy(IR), Gas Chromatography(GC) and Thermogravimetric Analysis(TGA) under nitrogen gas flow of 50 ㎖/min at various heating rates ranging from 4 to 20℃/min. The activation energy of thermal degradation in the mixture was determined using the Friedman method. The optimum thermal stabilization was obtained in PMMA/TBBA=95/5, PEMA/TBBA=97/3 and PBMA/TBBA=97/3 blend. At GPC analyses, the viscosity average molecular weight in the mixture was decreased slowly with decomposition temperature. At IR analyses, the value of carbonyl index in the mixture was increased slowly with reaction time and temperature. The thermal degradation mechanism of poly(alkyl methacrylate) and TBBA mixture was observed to be main chain scission under nitrogen environment.

선천성 매독 : 조기 선천성 매독의 방사선학적 소견

김동건(Dong Kun Kim),이정복(Jung Bock Lee),오기근(Ki Keun Oh) 대한피부과학회 1985 대한피부과학회지 Vol.23 No.1

A retrospective study was made of the previous medical records of 32 infants with congenital syphilis borne from mothers with untreated syphilis at Severence Hospital, Yonsei University College of Medicine during the years 1,972 through 19g3, These infants had a VDRL titer higher than 1: 8 with reactive FTA-ABS test and were also subjected to radiologic examinations. Radiologic changes and clinical features were analyzed, The following results were obtained: Of the total of 32 infants with congenital syphilis under 5 months of age, those under 1 month of age, were the most common group numbering a total of twelve. Of 32 infants with congenital syphilis, twenty-nine(91%) showed skeletal changes upon radiologic examination, Among them the different sites of bone involvernent revealed that the femur(92%) was the most commonly affected bone, followed by the humerus(88%), tibia(81%,), fibula(80%), ulna(72%), radius (68%). Among the same 29 infants a study of the presence of various abnormal bone changes showed that periostitis was the most common, being involved in 83%, the others being metaphysitis and periostitis(72%), metaphysitis(66%). 3. Among the clinicaI features presented in the 32 infants with congenital syphilis, hepatomegaly was the most common(63%,), followed by erythema with desquamation(47%), pneumonia(38%), maulopapules(34%).

구상흑연주철의 3상혼합조직의 변태거동에 관한 연구

김석원,김동건,유선경 ( Sug Won Kim,Dong Keun Kim,Seon Kyung Yo ) 한국주조공학회 1991 한국주조공학회지 Vol.11 No.5

N/A Ductile cast iron(DCI) with a multi-phase(ferrite-bainite-martensite) structures was produced by various special heat treatment. Intercritical heat treatment(I. C.), intermediate heat treatment(I. M.) and step quenching(S. Q.) were used to strengthen and toughen the fracture initiation sites such as graphite-marix interfaces and eutectic cell boundaries in DCI. The purpose of this study was to investigate of DCI by the special heat treatment. (I. C., I. M., and S. Q.) At a result, bainite nucleation rate at higher temperature was higher than that of at lower temperature, and shapes of bainite and martensite became bar /spheroidal type with increase of isothermal transformation time.

연구발표논문초록 ( 고분자 ) : Pmma - Tcnq , Pmma - Pcpa blend 의 기체투과와 열적 특성

박성자,김병철,김동건,설수덕 ( Seng Ja Park,Beung Keul Kim,Dong Keun Kim,Soo Duk Seul ) 한국화학공학회 1989 추계학술발표회 Vol.- No.-

연구발표논문초록 ( 고분자 ) : 내열 및 난연성 고분자재료가공의 최적화 반응모델에 관한 연구

손진언,설수덕,김동건 ( Jin Eon Sohn,Soo Duk Seul,Dong Keun Kim ) 한국화학공학회 1987 춘계학술발표회 Vol.- No.-

SiCp 입자강화 Al 복합재료에 대한 합금원소의 영향과 시효특성에 관한 연구

김석원(Sug Won Kim),이의종(Ui Jong Lee),우기도(Kee Do Woo),김동건(Dong Keun Kim) 한국주조공학회 2001 한국주조공학회지 Vol.21 No.1

The research on new DRA(discontinuous reinforced alloy) and CRA(continuos reinforced alloy) composites has been carried out to improve the properties of ceramic fiber and particle reinforced metal matrix composites(MMCs). Effects of alloying elements and aging conditions on the microstructures and aging behavior of Al-Si-Cu-Mg-(Ni)-SiCp composite have been examined. The specimens used in this study were manufactured by duplex process. The first squeeze casting is the process to make precomposite and the second squeeze casting is the process to make final composite. The hardening behavior was accelerated with decreasing the size of SiCp particle in the composites. It is considered that the dislocation density increased with increasing SiCp size, due to the different thermal deformation between Al matrix and SiCp during quenching after the solution treatment. Peak aging time to obtain the maximum hardness in 3㎛ SiCp reinforced Al composite was reduced than that in large size(5, 10㎛) of SiCp because of difference in dislocation density. Aging hardening responce(ΔH = H_(max)-H_(S.T)) of composites was greater than that of unreinforced Al alloy because of higher density of second phases in matrix.

연속반응기 ( CSTR ) 에서 비닐 아세테이트와 비닐 벤조에이트의 용액 공중합 (1)

김영규(Young Kyoo Kim),하창식(Chang Sik Ha),설수덕(Soo Duk Seul),김동건(Dong Keun Kim),조원제(Won Jei Cho) 한국고분자학회 1991 폴리머 Vol.15 No.6

단위가축영양 : 산란계 사료 3종류의 Bacillus subtilis의 첨가가 산란후기 계란 품질과 장내 미생물 및 경골에 미치는 영향

김재영 ( Jae Young Kim ),강창원 ( Chang Won Kang ),김지숙 ( Ji Sook Kim ),이소연 ( So Yeon Lee ),안병기 ( Byoung Ki Ahn ),김동건 ( Dong Gun Kim ),오성택 ( Sung Taek Oh ),이보근 ( Bo Keun Lee ),이완섭 ( Wan Seob Lee ),황용배 ( Yong 한국동물자원과학회 ( 구 한국축산학회 ) 2010 한국축산학회지 Vol.52 No.5

본 연구는 3종류의 B. subtilis 균주를 이용하여 제조한 생균제를 산란계 사료에 급여시 난 생산성, 난질, 난황 내 콜레스테롤, 장 내미생물 조성 및 경골 내 성상에 미치는 영향을 조사하였다. 76주령의 Hy-Line Variety Brown 산란계 160수를 공시하여 모두 4개 처리구에 4반복(반복당 10수)로 임의배치 후 6주간의 사양실험을 실시하였다. 산란계용 사료는 옥수수·대두박을 기초로 하여 대사에너지 2,700 kcal/kg와 조단백질 15.5%인 일반 사료 급여구를 대조구로 하였으며, (Tl) 처리구에는 B. subtilis Ch3을 0.05%, (T2) 처리구에는 B. subtilis Ch3 + B. subtilis W1 혼합제제를 0.05%, (T3) 처리구에는 시판되고 있는 B. subtilis 제품을 0.05% 수준으로 대조구 사료에 각각 혼합하여 급여하였다. 실험기간 동안의 난 생산성, 수당 사료섭취량, 난중 및 일 산란량 모두 변화가 나타나지 않았다. 난각 강도와 Haugh unit에서는 대조구와 비교하여 처리구에서 개선되었으며 (P<0.05), 간 내 GOT 및 GPT 효소는 처리구 간에 변화가 관찰되지 않았다. 맹장 내 총 균수와 lactic acid bacteria의 균수가 대조구와 비교하여 처리구에서 유의하게 개선되었다(P<0.05). 하지만 Coliforms 균수는 처리 간에 변화가 나타나지 않았다. 난황과 혈액 내 콜레스테롤 농도는 대조구와 비교하여 처리구에서 감소하였다(P<0.05). 또한 혈액 내 인지질도 대조구에 비교하여 처리구에서 감소하는 경향이 나타났다(P<0.05). 경골 파쇄강도는 처리간에 차이가 없었으나, 경골 내 회분 함량은 대조구와 비교하여 모든 실험구에서 개선시키는 결과가 관찰되었다 (P<0.05). 따라서 본 실험은 산란후기 사료 내 각각의 B. subtilis 균주를 첨가 급여 하였을 때 난각 강도와 Haugh unit를 개선시키는 효과가 관찰되었고 장내의 총 균수와 유산균 수를 증가시킴으로써 유리한 장 내 환경으로 개선시켰으며 또한 난황과 혈액 내 콜레스테롤을 감소시키는 효과가 나타났다. 또한 각각 3종류의 B. subtilis 첨가 급여 효과로 경골 내 회분 함량을 증가시킨 결과로 보아 Ca과 P과 같은 무기질 영양소의 체내 대사 이용률이 개선될 가능성이 시사되었다. 이와 같은 측면에 접근하여 B. subtilis의 수준별 첨가로 인한 혈액 및 경골의 Ca과 P의 축적률 변화와 사료 내 하향 수준의 무기질 공급 등의 추후 연구조사가 이뤄져야 할 가치가 있다고 판단된다. The objective of this study was to investigate the effects of three strains of Bacillus subtilis (B. subtilis) supplemented to diets on egg production, egg quality, egg yolk cholesterol levels, the profile of cecal microflora, and tibia characteristics in laying hens. One hundred sixty 76-week-old Hy-Line Brown layers were randomly divided into 4 groups with 4 replicates per group (10 birds per replicate). Birds in the control group were fed a com-soybean meal based diet. The remaining three treated groups were fed the control diet containing either 0.05% B. subtilis Ch3 (Tl), 0.05% B. subtilis Ch3 + B. subtilis WI (T2) or 0.05% B. subtilis commercial product (T3) for 6 weeks, respectively. There were no differences in feed intake, egg weight, egg production and egg mass among the groups. The dietary supplementation of B. subtilis improved eggshell strength and Haugh units compared to those of control (P<0.05). The activities of GOT and GPT in serum were not also affected by the dietary treatments. The population of total microbes and lactic acid bacteria in cecum were significantly increased by the dietary B. subtilis (P<0.05), but not the coliforms. The cholesterol concentration in egg yolk and serum in the treated groups were significantly decreased compared to those of control (P<0.05). Also, The levels of phospholipids in serum were significantly decreased compared to those of control (P<0.05). The supplementation of three strains of B. subtilis to diets significantly increased the contents of tibia ash compared to that of control (P<0.05). Thus, this study showed significant improvements in egg quality, such as eggshell strength and Haugh unit, by dietary B. subti/is strains. The B. subtilis strains added to the diets modulated the profiles of cecal microflora, reflecting beneficial effects in laying hens.

MIF (Molded-In Foaming) 공정에 적합한 고분자 기재의유변학적 특성 연구

김민근 ( Ming Eun Kim ),송형용 ( Hyeong Yong Song ),김동건 ( Dong Gun Kim ),김효준 ( Hyo Jun Kim ),박건욱 ( Geon Uk Park ),유재근 ( Jae Keun Yu ),현규 ( Kyu Hyun ) 한국고무학회 2014 엘라스토머 및 콤포지트 Vol.49 No.4

MIF (Molded-In Foaming) 공법의 발포 거동에 적합한 고분자 기재를 선정하기 위해 SBC (K-resin KK38)와 SBS (KTR 101와 KTR 301)의 유변물성을 측정하였다. SBS의 유변물성 (G``, G, η*)은 155 oC와 170 oC의경우 시간에 따라 유변물성 값의 변화가 거의 없으나, 185 oC와 200 oC의 경우에는 시간에 따라 증가하는 것을볼 수 있었다. 특히, KTR 301의 유변물성 값이 시간에 따라 큰 폭으로 증가하였다. 시간에 따른 유변물성 상승의정확한 원인을 확인하기 위해 155 oC와 200 oC에서 1800s 이후의 KTR 301의 비선형 유변물성을 진폭에 대해측정하였다. 155 oC에서는 일반적인 수지와 같은 한 번의 박화(thinning)현상이 관찰되나 200 oC에서는 두 번의박화현상이 관찰되었고 (Payne effect), 이는 고온에서 SBS가 겔화에 의한 경화가 일어난다고 볼 수 있다. 따라서이러한 유변물성으로부터 MIF 공법에 요구되는 특성(발포 초기 낮은 점도와 발포 완료 이후 높은 점도)에 적합한고분자 기재는 SBS KTR 301임을 확인할 수 있었다. In order to select polymer matrix for MIF (Molded-In Foaming) process, in this study, we investigated rheological properties of commercial polymers, SBC (Styrene-Butadiene Copolymers, K-resin KK38) and SBS (Styrene-Butadiene-Styrene, KTR 101 and KTR 301). In time sweep test, the rheological properties (G`, G, η*) of SBS at 155and 170 oC display almost constant value as a function of time from 0 s to 1800 s. On contrast, the rheological properties of SBS at 185 and 200 oC exponentially increase as a function of time. It could be due to gelation of SBS at high temperature conditions. These increment of rheological properties are not observed in SBC. From LAOS (large amplitude oscillatory shear) test, the nonlinear rheological properties of SBS at 155 and 200 oC after 1800 s are compared. The nonlinear rheological properties at 155 oC show simple strain thinning behavior such as linear homo polymer, however, the nonlinear rheological properties at 200 oC show 2 times strain thinning behavior (Payne effect). It well match with the gelation of SBS at 200oC. From rheological studies, it is confirmed that the proper polymer matrix for MIF process (low rheological properties at initial time and high rheological properties after process) is SBS KTR 301.