나프탈렌기를 갖는 새로운 액정폴리우레탄의 합성 및 특성

이종백,이광현 한국고무학회 2005 엘라스토머 및 콤포지트 Vol.40 No.1

새로운 형태의 액정성 폴리우레탄을 2,6-bis(ω-hydroxyalkoxy)naphthalene (BHNm; m= 5, 6, 8, 11)과 2,5-tolylene diisocyanate 또는 1,4-phenylene diisocyanate의 중부가 반응에 의해 합성하였다. 폴리우레탄의 고유 점성도는 0.28-0.43 dL/g 였다. 열적 성질은 DSC 및 편광현미경에 의해 측정되었다. 단량체 BHNm과 메틸치환기를 가진 2,5-tolylene diisocyanate에 의해 합성된 폴리우레탄은 모두 단방성 액정성을 나타내었다. 그러나 BHNm와 1,4-phenylene diisocyanate를 합성한 폴리우레탄에서는 DSC와 편광현미경으로 조사 결과 전혀 액정성을 나타내지 않았다. Novel polyurethanes containing no mesogenic unit were synthesized by the polyaddition reaction of para-type diisocyanates such as 2,5-tolylene diisocyanate (2,5-TDI) or 1,4-phenylene diisocyanate (1,4-PDI) with 2,6-bis(ω-hydroxyalkoxy)naphthalene (BHNm; m= 5, 6, 8, 11). Intrinsic viscosities of the polymers were in the range of 0.28-0.43 dL/g. The thermal properties of these polymers were studied by differential scanning calorimetry and polarizing microscopy. Polyurethanes prepared from BHNm and 2,5-TDI having methyl sub stituent on the phenylene unit exhibited monotropic liquid crystallinity. However, in the series of polyurethanes prepared from 1,4-PDI and BHNm, no explicit mesomorphic behavior was observed by differential scanning calorimetry and polarizing microscopy.

o-클로로톨루엔과 질소 분자의 충돌 시 에너지 전달과 결합 해리에 대한 연구

이종백,강지현,김성돈,윤도협,조가영,이상권 한국과학영재교육학회 2017 과학영재교육 Vol.9 No.3

This study is based on Research and Education (R&E) project in Goksung high school. Energy flow and C–H and C–Cl bond dissociations in o-chlorotoluene(OCT) in collision with N2 is studied using classical trajectory procedures. The energy loss by the vibrationally excited OCT is small, but it increases with increasing total vibrational energy content ET of OCT between 5,000cm-1 and 30,000cm-1. Intermolecular energy transfer occurs mainly through vibration-translation(V–T) and vibration-vibration(V–V) pathways. The intramolecular energy flow between C–H and C–Cl stretching vibration in highly excited OCT (60000 – 60300 cm-1 ) leads to bond dissociation. The probabilities of C–H and C–Cl bond dissociation are 10-5~10-1 and increase exponentially with increasing vibrational excitation of OCT. On the other hand, the dissociation time of C-Cl bond is longer than that of C-Hmethylbond. 이 연구는 곡성고에서 진행하는 Research & Education (R&E) 과제로 수행되었다. o-클로로톨루엔(OCT) 과 질소 분자가 충돌 시 에너지 전달과 C-H 및 C-Cl 결합해리를 고전 궤적 과정을 통해 연구하였다. 진동적으로 들뜬 OCT 분자의 에너지 감소는 적었지만, OCT 의 총에너지량(ET) 5,000cm-1 ~ 30,000cm-1 사이에서 ET가 증가함에 따라 점차로 증가하였다. 분자 간 에너지 전달은 주로 진동-병진(V–T) 과 진동-진동(V–V) 전달 경로를 통해 일어났다. OCT의 에너지가 높게 들뜬 영역 (60,000 – 60,300 cm-1)에서는 C-H 와 C-Cl 신축 진동 사이의 분자내 에너지 전달을 통해 각 결합의 해리가 일어나게 된다. C-H 와 C-Cl 결합의 해리 확률은 10-5~10-1 정도이며, OCT의 진동 에너지가 증가함에 따라 확률도 지수적으로 증가하였다. 또한 C-Cl결합의 해리 반응 시간이 C-Hmethyl 결합의 해리 반응 시간보다 더 길게 나타났다.

The Relationship between Isokinetic Trunk, Leg Strength and Isometric Mid-Thigh Pull Test, Counter Movement Jump in National Rowing Athletes

이종백,김영균 대한운동학회 2020 아시아 운동학 학술지 Vol.22 No.3

[OBJECTIVES] The purpose of this study was to analyze the relationship between isokinetic leg strength and maximum Isometric Med-Thigh Pull Test(IMTP) and maximum height of Counter Movement Jump (CMJ) in Korean national rowers. [METHODS] Each eight male and female athletes were participated in the study. Isometric IMTP, CMJ, and isokinetic trunk, hip, and knee strength were measured to analyze the relationship between the IMTP, CMJ and isokinetic strength. The correlation between variables was analyzed by the step-wise method of multiple regression analysis after analyzing the correlation between dependent and independent variables. [RESULTS] Knee, Hip and trunk isokinetic flexion and extension strength showed high correlation with maximum IMTP with the all participants. Knee extension and trunk flexion isokinetic strength showed higher correlation with IMTP. Knee extension isokinetic strength showed high correlation with CMJ. [CONCLUSIONS] For strengthening exercise of National rowers, ipsilateral strength balance and agonistantagonist strength balance of leg and trunk should be considered to improve performance efficiently.

액정폴리우레탄의 합성과 열적성질

이종백 한국공업화학회 2002 한국공업화학회 연구논문 초록집 Vol.2002 No.0

최근에 액정성고분자는 높은 분자 배향성을 응용하여 고강도 재료에 많이 사용 되고 있다. 특히, Kevlar는 폴리아미드 액정상에서 얻어낸 섬유로, 방탄조끼, 정박 케이불 등에 특수한 용도로 다양하게 사용되고 있으며, 이러한 액정고분자의 대부분은 폴리에스테르계이다. 산업체에서 고분자 재료중에서 가장많이 사용하고 있는 재료중의 하나인 폴리우레탄에 대한 연구는 활발하게 진행되고 있지만 아직까지 기능성을 가진 액정 폴리우레탄에 대해서는 많은 연구가 진행되지 않고 있다. 최근에 폴리우레탄의 고성능화를 향상시키기 위해 여러 가지 구조의 액정성 폴리우레탄을 합성하여 메카니즘 규명에 대해서 연구되고 있다. 특히, 메소겐으로 비페닐기를 함유한 diol 과 여러 종류의 diisocyanate를 사용하여 합성한 플리우레탄에 대해서 액정성에 관하여 지속적으로 보고 한 적이 있다. 본 연구에서는 4,4'-Bis(9-hydroxynonoxy)biphenyl (BP9)를 새롭게 합성하여 여러 종류의 diisocyanate 즉, 2,6-tolylene diisocyanate (2,6-TDI), 2,5-tolylene diisocyanate (2,5-TDI), 2,4-tolylene diisocyanate (2,4-TDI), 1,4-phenylene diisocyanate (1,4-PDI), hexamethylene diisocyanate (HMD)을 사용하여 폴리우레탄을 합성한 결과 여러 종류의 액정성 나타내었다. 액정성에 관한 열적 성질에 관하여 연구하였다.

Reactions of Gas-Phase Atomic Hydrogen with Chemisorbed Hydrogen on a Graphite Surface

이종백,김유항,Hyung Kyu Shin 대한화학회 2007 Bulletin of the Korean Chemical Society Vol.28 No.4

The reaction of gas-phase hydrogen atoms H with H atoms chemisorbed on a graphite surface has been studied by the classical dynamics. The graphite surface is composed of the surface and 10 inner layers at various gas and surface temperatures (Tg, Ts). Three chains in the surface layer and 13 chains through the inner layers are considered to surround the adatom site. Four reaction pathways are found: H2 formation, H-H exchange, H desorption, and H adsorption. At (1500 K, 300 K), the probabilities of H2 formation and H desorption are 0.28 and 0.24, respectively, whereas those of the other two pathways are in the order of 10-2. Half the reaction energy deposits in the vibrational motion of H2, thus leading to a highly excited state. The majority of the H2 formation results from the chemisorption-type H(g)-surface interaction. Vibrational excitation is found to be strong for H2 formed on a cold surface (~10 K), exhibiting a pronounced vibrational population inversion. Over the temperature range (10-100 K, 10 K), the probabilities of H2 formation and H-H exchange vary from 0 to ~0.1, but the other two probabilities are in the order of 10-3.

The Relationship between Dynamic Balance Ability and Low Limb Isokinetic Muscle Function of Elite Judo Athletes

이종백,김영균 대한운동학회 2020 아시아 운동학 학술지 Vol.22 No.2

[OBJECTIVES] The purpose of this study is to examine the relationship between lower extremity isokinetic muscle strength and dynamic balance ability of elite judo athletes and improve the efficient dynamic balance ability of athletes. [METHODS] A total of 26 male and female judo national candidates (13 males and 13 females) were participated. Isokinetic strength and dynamic balance in three consecutive areas of the lower limbs (knee, hip, waist) were measured. Multiple regression analysis step selection method was used to analyze the correlation between isokinetic strength measurement variables and dynamic balance ability. In addition, the results were analyzed by dividing the difference of fitness variables between male and female athletes and male and female athlete groups. [RESULTS] The male athlete group showed higher muscle strength in all areas of isokinetic strength (p <.01). Stability was statistically significantly higher (p <.05). There was interrelationship between the lower extremity isokinetic strength and the dynamic balance of the lower extremities in male and female athletes. The trunk flexion showed the highest correlation with the dynamic balance in the male athletes, and trunk flexion and hip extension in female athletes. [CONCLUSIONS] The trunk muscle strength showed the highest correlation with the dynamic balance ability in male and female athletes.

Mesogen 을 포함하지 않은 액정 polyurethane 의 합성과 열적성질에 관한 연구

이종백,최대웅 ( Jong Back Lee,Dae Woong Choi ) 한국공업화학회 1997 공업화학 Vol.8 No.2

액정 polyurethane은 DMF 용매중 1,4-bis(6-hydroxyhexoxy)benzene (BHB6)과 2,5-tolylene diisocyanate (2,5-TDI)를 중부가 반응에 의해서 합성하였다. 고유점도는 0.26, 0.42 ㎗/g였다. 생성된 polyurethane의 열적성질 및 구조확인은 DSC, 편광현미경, X-ray회절 그리고 ¹H-NMR 및 FT-IR에 의해 확인하였다. 특히 분자량이 서로 다른 polyurethane 2,5-TDI/BHB6의 열적성질 및 물성에 대해서 비교 검토하였다. 고유점도가 [η]=0.26인 polyurethane 2,5-TDI/BHB6는 monotropic 액정성을 나타내었다. 이러한 것은 구조적으로는 mesogen을 포함하고 있지 않다. 예를 들면 LCPU-L(저분자량)은 T_(I.LC)(등방성액체상전이점-액정) 및 T_(LC-k)(액정-결정)은 122℃부터 89℃까지 관찰되었다. Liquid crystalline polyurethanes were prepared from 1,4-bis(6-hydroxyhexoxy)benzene (BHB6) and 2,5-tolylene diisocyanate (2,5-TDI) solution polymerization in dimethylformamide produced intrinsic viscosities in the range 0.26 and 0.42 ㎗/g. The polyurethanes were investigated by DSC, Polarizing microscopy, X-ray, ¹H-NMR and IR spectroscopy. Polyurethanes of two different molecular weights were studied in detail and these will be referred to as low molecular weight and high molecular weight. Polyurethane 2,5-TDI/BHB6 with [η]=0.26 ㎗/g prepared from BHB6 and 2,5-TDI, exhibited monotropic liquid crystallinity, although these polyurethanes contained no mesogenic core unit. For example, LCPU-L(low molecular weight) exhibited T_(I.LC) of 122 ℃ and T_(LC-k) of 89℃.

액정폴리우레탄의 합성과 물질적 성질

이종백,이상배 東義大學校産業技術開發硏究所 2003 産業技術硏究誌 Vol.17 No.-

다섯 종류의 새로운 형태의 액정성 폴리우레탄을 4,4'-Bis(7-hydroxyheptoxy)biphenyl(BP7)와 2,6-tolylene diisocyanate (2,6-TDI), 2,5-tolylene diisocyanate (2,5-TDI), 2,4-tolylene diisocyanate (2,4-TDI), 1,4-phenylene diisocyanate (1,4-PDI) 및 hexamethylene diisocyanate (HDI)의 중부가 반응에 의해 합성하였다. 단량체 BP7은 스멕틱상을 형성하였으며 1,4-PDI/BP7을 제외한 나머지 폴리우레탄에서는 모두 액정성을 나타내었다. 생성된 폴리우레탄의 구조는 IR과 1H NMR 스펙트럼에 의해 확인하였고 열적 성질은 DSC와 편광현미경으로 관찰하였다. A new series of liquid crystal polyurethanes was synthesized by the polyaddition reaction of diisocyanates such as 2,6-tolylene diisocyanate (2,6-TDI), 2,5-tolylene diisocyanate (2,5-TDI), 2,4-tolylene diisocyanate (2,4-TDI) and 1,4-phenylene diisocyanate (1,4-PDI), hexamethylene diisocyanate (HDI) with 4,4-Bis(7-hydroxyheptoxy)biphenyl (BP7). 4,4'-bis(7-hydroxyheptoxy)biphenyl exhibited a smetic type mesophase. Mesophase was found for all synthesized liquid crystalline polyurethanes except 1,4-PDI/BP7. The structures and the thermal properties of polyurethanes were studied by using FT-IR and ^1H NMR spectroscopy, DSC measurements and a polarizing microscope equipped with a heating stage.

금속 표면에 대한 비활성 기체의 반응역학 : MTGLE 모형

이종백,김상아,이상권 全南大學校 師範大學 科學敎育硏究所 2012 科學敎育硏究誌 Vol.36 No.1

The reaction dynamics of inert gases, Ne, Ar and Kr on the tungsten and copper surfaces have been studied by the classical trajectory approach. Flow of energy between the reaction zone and the bulk solid phase is treated in the molecular time-scaled generalized Langevin (MTGLE) equation approach, and compared with the linear chain model. Whereas the reaction almost occurs to the adsorption collision at low collisional energy, the direct collision occurs as the collisional energy increases over the critical energy. The lower the temperature is, the greater the energy transfer( ) is, and the  is converged to the constant limiting value. The energy transfer  depends on the mass difference between the surface and incident particle, and it increases as the mass difference is decreased. Futhermore, the energy transfer on tungsten surface is greater than the copper, because the latter is smaller in the mass difference. The significant diffrences in the mechanism of the energy transfer is the dissipation process, that is, in the MTGLE model it dissipates to the surface continuously after collision whereas in the linear chain model it remains on the surface. Thus, in the collision energy is low, linear atom-chain model is not suitable, because the adsorption probability is increased.

비페닐 구조를 가지는 액정폴리머의 합성과 특성

이종백,이광현,강병철 동의대학교 산업기술개발연구소 2005 産業技術硏究誌 Vol.19 No.-

A series of thermotropic polyurethanes containing biphenyl units was synthesized by polyaddition reaction of diisocyanates such as 2,6-tolylene diisocyanate, 2,5-tolylene diisocyanate, 2,4-tolylene diisocyanate, and 1,4-phenylene diisocyanate, and hexamethylene diisocyanate with 4,4'-Bis(9-hydroxynonoxy)biphenyl (BP9). Structures of the monomer and the corresponding polymers were identified using FT-IR and ^(1)H-NMR spectroscopies. Their phase transition temperatures and thermal stability were also investigated by differential scanning calorimetry and optical polarizing microscopy. 4,4'-bis(9-hydroxynonoxy)biphenyl exhibited a smectic type mesophase. Mesophase was found for all synthesized liquid crystalline polyurethanes except 1,4-PDI/BP9 based polyurethane.