내열성 액정 고분자의 합성 및 복합재료

조병욱,전옥철,김윤준,한철,최재곤 조선대학교 생산기술연구소 1999 生産技術硏究 Vol.21 No.2

A new thermotropic liquid crystalline copolyester(TLCP) was synthesized by condensation polymerization of 2,6-naphthalene dicarbonyl chloride with the corresponding diol having a tetramethylene and a hexarnethylene group. The blends of the TLCP with PEN were prepared by the coprecipitation from a common solvent. The TLCP and blends (2, 5, 10 and 20wt% TLCP) were characterized in terms of their thermal, mechanical properties and morphology. The TLCP in the melt state showed nematic mesophase identified by thread-like optical texture. The glass transition temperature (T_(g)) and cold crystallization temperature (T_(c)) of PEN in the blends decreased with increasing the content of TLCP and the TLCP acted as anucleating agent for the matrix polymer. Interfacial adhesion between the TLCP and PEN seemed to be poor. The modulus of TLCP/PEN blends was enhanced as the TLCP content increased.

Organoclay/TLCP nanocomposites의 제조 및 특성

김원,최재곤,조병욱 조선대학교 생산기술연구소 2003 生産技術硏究 Vol.25 No.2

The organoclay/TLCP(Thermotropic Liquid Crystal Polymer) nanocomposites were prepared by in-situ polymerization. To discuss the effect of the organoclay contents on the polymer properties, we prepared organoclay/TLCP nanocomposites of 2, 5, 10wt% in organoclay contents. The organoclay/TLCP nanocomposites were characterized by scanning electron microscopy(SEM), X-ray diffractometer(XRD), dynamic mechanical thermal analysis (DMTA), differential scanning calorimetry (DSC), and thermogravimetric analyzer(TGA). The bending moduli of organoclay/TLCP nanocomposites were improved with increasing organoclay contents. The TLCPs and organoclay/TLCP nanocomposites showed the nematic phase above those melting ternperature(T_(m)). The TLCPs and organo clay/TLCP nanocomposite seem to act as plasticizers and nucleating agents in the matrix polymers.

고분자 복합재료를 위한 액정중합체(I)

조철형,조성휴,조병욱,김정규,김숭평,권중근 조선대학교 생산기술연구소 1983 生産技術硏究 Vol.1983 No.-

Copolyesters containing oxybenzoate as a rigid rod molecule and methylene group and dimethyl tetramethyl disiloxane as flexible spacers were prepared by room temperature solution polymerization for the purpose of the developement of polymeric composite materials. The thermal properties and the characteristics of the polymers were investigated by DSC and a polarizing microscope. The polymers may be formed nematic liquid crystal phase, and the thermodynamic characteristics of their mesophase to isotropic phase transition could be explained on the basis of its structural features.

새로운 열방성 액정중합체의 합성과 PET와의 블렌드

조정대,김희종,최재곤,조병욱,유지강 조선대학교 생산기술연구소 1997 生産技術硏究 Vol.19 No.1

Blends of new thermotropic liquid crystalline polymer(TLCP) with poly(ethylene terephthalate)(PET) were prepared by the coprecipitation from a common solvent. The thermal, mechanical properties and morphology of the blends(2wt%, 5wt%, lOwt% and 20wt% TLCP/PET) were examined. In the blends, liquid crystalline phase did not reveal any significant macrophase separation and thermal degradation at the processing temperature. According to the scanning electron micrograps, the TLCP domains in matrix were found to be more or less finely dispersed with 0.2㎛ to 0.4㎛ in size and interfacial adhesion between the TLCP and matrix polymer was excellent. Results of mechanical property measurement show that modulus of TLCP/PET blend was enhanced with increasing TLCP content.

폴리에틸렌 나노 복합체의 특성 연구

이재철,박일수,최재곤,조병욱 조선대학교 생산기술연구소 2004 生産技術硏究 Vol.26 No.1

Thermal property, structure and morphology of the LDPE/ organo-clay nano-composites prepared melt blending were investigated by using thermogravimetric analyzer (TGA), X-ray diffractometer (XRD) and scanning electron microscope (SEM). When the composition ratios of the compounds of LDPE/PE-g-MA/organo-clay were 70-90/10~30/1~5 (w/w/w), thermogravimetric analyses (TGA) performed in air showed a great increase in thermal stability of the LDPE/organo-clay nanocomposties. The maximum decomposition temperature of LDPE/organo-clay nanocomposite was increased by about 80 ℃ compared with pure LDPE. X-ray diffractograms of LDPE/organo-clay nanocomposites showed that the intercalation of polymer chains lead to increase the spacing between clay layers.

PTT단위를 갖는 액정중합체의 합성 및 블렌드

김원,최유성,이태양,최재곤,홍완해,조병욱 조선대학교 생산기술연구소 2003 生産技術硏究 Vol.25 No.1

This study explores the potential of improving the physical properties of poly(trimethylene terephthalate) (PTT) by inducing thermotropic liquid crystalline polymers. The TLCP was synthesized by polycondensation reaction of terephthaloyl chloride with corresponding diols. The TLCP used was copolymers containing random PTT groups on the polymer backbone. The PTT moieties were used to increse compatibility between the PTT and the TLCP. The TLCP showed the nematic phase above those melting temperature(T_m) The TLCP seems to act as plasticizers and nucleating agents in the matrix polymers Liquid crystalline phase did not reaveal any significant macrophase separation and thermal degradaton under the temperature of processing condition.

EVA Nanocomposites 제조 및 특성연구

김영용,박일수,정효선,최재곤,김정규,조병욱 조선대학교 생산기술연구소 2003 生産技術硏究 Vol.25 No.1

Ethylene vinyl acetate random copolymer(EVA)/layered-silicate nanocomposites were prepared by melt or solution blending. The TGA thermograms of EVA/ layered-silicate nanocomposites showed an improved thermal stability as the layered-silicate contents increased. The decomposition temperature of nanocomposite was increased around 10℃ compared with pure EVA at 50% weight loss under N_2 atmosphere And in an air atmosphere, temperature difference in 50% wt loss between the nanocomposlte and the virgin EVA was around 100℃ The moduli in their thermomechanical module of nanocomposite are higher than pure EVA. Interlayered spacings of nanosilicates were slightly increased when prepared by melt blending. On the other hand, they were remarkably increased when prepared by solution blending. It may be explained that EVA moiety of the copolymer showed partial adsorption behavior on the surface layer of the silicate. It also revealed that the adsorption is more effective in the solution blending than in the melt blending.

곁사슬을 갖는 새로운 액정중합체의 합성 및 특성

전옥철,김윤준,류범영,최재곤,조병욱,홍진후 조선대학교 생산기술연구소 1999 生産技術硏究 Vol.21 No.1

A series of wholly aromatic polyesters with side chains were synthesized by solution polycondensation from 2,5-dialkoxyterephthaloyl chlorides with the corresponding diol. The polymers showed the schlieren textures which is indicative of a nematic phase above their melting temperature. The inherent viscosities (η_(inh)) measured at 35℃ in phenol/p-chlorophenol/1,1,2,2-tetrachloroethane were 0.56-0.98 dℓ/g. The glass transition temperature (T_(g)) and melting temperature (T_(m)) decreased with increasing the length of the alkoxy side chain. Initial decomposition temperatures in TGA occurred at 338 ~ 363℃ in N₂ gas and thermal stability of polymers decreased with increasing the length of the side chain.

정신분열병에 대한 리스페리돈의 효과 및 안정성

이민수,김용구,김영훈,연병길,오병훈,윤도준,윤진상,이철,정희연,강병조,김광수,김동언,김명정,김상훈,김희철,나철,노승호,민경준,박기창,박두병,백기청,백인호,손봉기,손진욱,양병환,양창국,우행원,이정호,이종범,이홍식,임기영,전태연,정영조,정영철,정인과,정인원,지익성,채정호,한상익,한선호,한진희,서광윤 大韓神經精神醫學會 1998 신경정신의학 Vol.37 No.1

연구목적 : 본 시험의 목적은 임상시험 시작전에 연구자들을 대상으로 PANSS Workshop을 통하여 PANSS, ESRS에 대한 국내에서의 표준화 작업을 구축하고 새로운 정신병 치료제인 리스페리돈의 효과와 안정성을 재확인하여 리스페리돈 사용에 대한 적정화를 이루는데 있다. 연구방법 : 1996년 4월부터 1996년 9월까지 국내 39개 대학병원 정신과에 입원중인 혹은 증상이 악화되어 입원하는 정신분열병 환자 377명을 대상으로 다시설 개방 연구를 시행하였다. 1주일간의 약물 배설기간을 가진후, 리스페리돈을 8주간 투여하였고, 기준점, 1주, 2주, 4주, 그리고 8주후에 평가되었다. 용량은 제1일에는 리스페리돈 1mg씩 1일 2회, 제2일에는 2mg씩 1일 2회, 제3∼7일에는 3mg씩 1일 2회 투여하였다. 이후 환자의 임상상태에 따라 임의로 증량할 수 있으며, 최대 일일 16mg을 초과하지 않도록 하였다. 추체외로 증상을 조절하기 위한 투약을 허용하였다. 임상증상 및 부작용의 평가는 PANSS(Positive and Negative Syndrome Scale), CGI(Clinical Global Impression) 그리고 ESRS(Extrapyramidal Symptom Rating Scale)을 사용하였다. 연구결과 : 377명중 343명(91%)이 8주간의 연구를 완결하였다. 치료 종결시점인 8주후 PANSS 총점수가 20% 이상 호전된 경우를 약물 반응군으로 정의할때, 약물반응군은 81.3%였다. 리스페리돈에 반응하는 예측인자로는 발병연령, 이전의 입원 횟수, 유병기간이 관련 있었다. 리스페리돈은 1주후부터 PANSS양성, 음성, 및 일반정신병리 점수상에 유의한 호전을 보여 효과가 빨랐다. CGI의 경우도 기준점에 비해 1주후부터 유의한 감소를 나타내었다. ESRS의 경우, 파킨슨 평가점수는 기준점과 비교해 투여 1주, 2주, 4주후 유의하게 증가되었다가 8주후 기준점과 차이가 없었다. Dystonia 평가점수는 1주후만 유의한 증가를 보였으며, dyskinesia 평가점수는 유의한 차이가 없었다. 혈압, 맥박수의 생명징후 및 일반 혈액학 검사, 생화학적 검사, 심전도 검사에서 유의한 변화는 없었다. 결 론 : 이상의 다시설 개방 임상 연구를 통해 리스페리돈은 정신분열병 환자에서 양성증상뿐만 아니라 음성증상 및 전반적인 증상에도 효과적인 것으로 사료된다. 보다 명확한 평가를 위해서는 다른 항정신병약물과의 이중맹검 연구가 필요할 것으로 생각되며, 또한 장기적 치료에 대한 평가도 함께 이루어져야 하겠다. Objective : The purpose of this study was to investigate the efficacy and safety of risperidone in the treatment of Korean schizophrenic patients. Method : This multicenter open study included 377 schizophrenic patients drawn from 39 university hospitals. After a wash-out period of 1 week, the schizophrenic patients were treated with risperidone for 8 weeks and evaluated at 5 points ; at baseline, and 1, 2, 4 and 8 weeks of treatment. The dose was increased from 2mg/day(1mg twice daily) to 6mg/day(3mg twice daily) during the first week and adjusted to a maximum of 16mg/day over the next 7 weeks according to the patient's clinical response. Medication to control extrapyramidal symptoms was permitted. The psychiatric and neurological status of the patients was assessed by PANSS, CGI, and ESRS scales. Results : 343(91%) of 377 patients completed the 8-week trial period. Clinical improvement, as defined by a 20% or more reduction in total PANSS score at end point, was shown by 81.3% of patients. The predictors of response to risperidone were associated older age, shorter duration of illness, fewer previous hospitalization. Risperidone had rapid onset of action ; a significant decrease of the total PANSS and three PANSS factor(positive, negative, general), and CGI was already noticed at the end of first week. For the ESRS, parkinsonism rating scores were significantly increased until week 4 comparing with baseline. Dystonia rating scores were significantly increased until week 1, and dyskinesia rating scores were not significantly changed during the study. Laboratory parameters including vital sign, EKG, hematological, and biochemical values showed no significant changes during the trial. Conclusions : This study suggests that risperidone is generally safe and effective against both the positive and negative symptoms in our group of patients.

Synthesis and Liquid Crystalline Properties of Dimesogenic Compounds Containing Trifluoromethyl Substituents at Terminal Phenylene Rings and Central Decamethylene Spacer

Jo, Byung-Wook,Choi, Jae-Kon,Jin, Jung-Il,Chung, Bong-Yong Korean Chemical Society 1990 Bulletin of the Korean Chemical Society Vol.11 No.4

A series of new dimesogenic compounds whose mesogens are of aromatic ester or amide type having a trifluoromethyl $(CF_3)$ substituent at the para-position of each terminal phenolic rings were prepared and their liquid crystalline properties were studied by differential scanning calorimetry (DSC) and on a cross-polarizing microscope. The compounds have two identical mesogenic units bracketing a central decamethylene spacer. Trifluoromethyl group appears to favor the formation of smectic phases when it is attached to a phenoxy or anilide terminal. Its group efficiency for mesophase formation seems to be inferior to other common substituents. A thermodynamic analysis of the phase transitions was made and the results were explained in relation to the structures of the compounds.