위피 플랫폼에 의한 모바일게임 컨텐츠 (WMC) 개발

최재영,황병곤 대구대학교 정보통신연구소 2006 情報通信硏究 Vol.4 No.1

아이소소바이드/반응성 올리고머에 의한 에폭시 수지의 개질(Ⅱ)

최향희,전윤,최재곤 조선대학교 생산기술연구소 1998 生産技術硏究 Vol.20 No.2

본 연구에서는 일반적인 상용 에폭시수지를 아민 말단 반응성 올리고머와 isosorbide를 이용하여 물성 변화를 시도하였다 유연한 지방족 고리형의 isosorbide (DDS)는 열가소성 rich-phase형성에 큰 영향을 주며, isosorbide/반응성 올리고머를 도입한 열경화성 에폭시 수지는 3개의 서로 다른 몰폴러지를 보여줌을 알 수 있었다. 파괴에너지는 isosorbide 도입량 34.2%에서 3배 정도(815J/㎡) 증가하였는데, 모듈러스의 감소(△E = 0.8GPa)는 그렇게 크지 않았다. 그중 강인한 수지는 isosorbide 도입량 34.2%, 44.5%으로 열가소성 rich-phase가 연속상이고, 열경화성 rich-phase가 분산상인 상태에서 흡수된 에너지로 밝혀졌다. 또 24.9% 도입의 경우 혼합된 두 개의 연속상이 존재함을 알 수 있었으며 파괴에너지는 열경화성 연속상과 열가소성 연속상의 중간정도의 값을 보여 주었다. isosorblde/반응성 올리고머를 도입한 열경화성 에폭시 수지계의 파괴저항은 연속상 가교점 사이의 분자량과 CSIF를 관련 지워 잘 설명할 수 있음을 알 수 있었다. 각 상의 T_(g) 이하 온도에서 수지의 저장 탄성율은 flexural modulus와 비슷한 값을 보여주지만, 열경화성 rich-phase의 T_(g) 이하, 열가소성 rich-phase의 T_(g) 이상의 온도영역에서는 3개의 서로 다른 상이 관찰되었다. 결론적으로 isosorbide/반응성 올리고머를 도입한 에폭시 수지계의 파괴에너지는 충분히 높고, 적절한 탄성율로 여러 범위의 응용이 가능할 것으로 생각된다. A commercialized Epoxy resin was modified with isosorbide and amine terminated reactive oligomer. Isosorbide which has aliphatic cyclic chemical structure was found to influence on the formation of thermoplastic-rich continuous phase. It was found that interaction and phase behaviors of the thermoplastic-rich and thermoset-rich continuous phases of this resin system have influence strongly on physical properties and morphology of the resin, This resin system was shown to display three morphologically distinct states that determine their thermal and mechanical properties. A three-fold increase in the fracture energy was observed without a significant decrease in the modulus. The toughest resins have ductile energy absorbing thermoplastic-rich continuous phases with thermoset-rich inclusions 34.2% and 44.5% of isosorbide loading levels while the more brittle, lower loading level materials, 7.7% and 16.0%, had thermoset-rich continuous phases with thermoplastic-rich inclusions. The 24.9% loading level system possessed a mixed continuous phase morphology and had a fracture energy intermediate between the thermoset-rich continuous system and the thermoplastic-rich continuous phase system. Phase seperation and morphology of the resin system also were confirmed by a transmission electron microscopy and dynamic mechanical analysis. It was further demonstrated that the fracture resistance of this system could be very well modelled by relating the average molecular weight between crosslinks of the continuous phase with the critical stress intensity factor. The characterized phase mixing led to the determining of a proportional relationship between the critical stress intensity factor and the average molecular weight between crosslinks of the continuous phase. The observed proportionality between these two variables may indicate that a single fracture mechanism, depending on the molecular weight between crosslinks of the continuous phase exists This relationship, if valid, indicates that the nature of the inclusion in these reactive thermoplastic oligomer and isosorbide resin system is insignificant, and that the fracture resistance of these rosins Is determined by the nature of the continuous phase.

Trimethylene terephthalate 단위를 갖는 액정중합체와 PTT와의 블렌드

최유성,김선,최재곤 조선대학교 생산기술연구소 2004 生産技術硏究 Vol.26 No.2

New thermotropic liquid crystalline polymers (TLCP) having a trimethylene terephthalate (TT) were synthesized for application of in-situ composite, and the blends of the TLCP with PTT 〔Poly(trimethylene terephthalate)〕 were conducted in order to get a so-called in-situ reinforced polymeric composite. The thermal and morphology of the blends (2, 5, 10, 15, and 20 wt% TLCP/ PTT) were investigated. The blends showed good interfacial adhesion with domain sizes 0.3㎛ ~ 0.5㎛ in diameter and well developed fibrillation in the monofilaments.

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.

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.

열방성 액정중합체와 PEN과의 블렌드에 관한 연구

전옥철,최재곤 조선대학교 생산기술연구소 1998 生産技術硏究 Vol.20 No.1

A new semirigid liquid crystalline polyester(LCP) was synthesized by polycondensation of 2,6-naphthalenedicarbonyl dichloride with the corresponding diol having a hexamethylene group. Blends composed of poly(ethylene 2,6-naphthalate, PEN) were prepared by the coprecipitation from a common solvent. The thermal. mechanical properties and morphology of blends were examined using differential scanning calorimeter(DSC), scanning electron microscope(SEM), and dynamic mechanical thermal analyzer(DMTA). The glass transition ternperature(T_(g)) and the cold crystallization ternperature(T_(c)) of the PEN in the blends decreased with increasing the content of LCP and the LCP acted as a nucleating agent for the matrix polymers. The LCP phases in the blends were found to be finely and uniformly dispersed by SEM micrographs. The modulus of LCP/PEN blends were enhanced on the LCP content increase.

폴리올레핀 자동차 범퍼수지의 화학적 재활용 연구

지성완,홍진후,최재곤 조선대학교 생산기술연구소 1998 生産技術硏究 Vol.20 No.2

Recycling of thermoplastic polyolefins bumper has been carried out by stirring a coarse-crushed plastic material inside a chemical reactor using dichloromethane(MC) to release the paint film and drying the solvent. Chemical method adversely affects the physical properties or surface quality of the final product. It was found that wettability and surface tension of these polymers did not influence coating properties significantly. The diffusion coefficient of MC in PP/EPR blend has been monitored using an attenuated total reflection FT-IR. The test also demonstrated both the accuracy and quickness of FT-IR ATR experiment for measuring the diffusion coefficient of chemical recycling system Crystallinity and fractional free volume were very sensitive to the diffusion rates of small molecules in polymers as well as to the composition in recycled PP/EPR blends. It was suggested that concentration of the PP/EPR resins obtained from recycling process must be lower than 40wt percent in compounding.

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.

폴리스타이렌 아이오노머와 액정중합체 블렌드의 기계적 성질

김희석,김준섭,최재곤,박기주,윤용국,진정일 조선대학교 생산기술연구소 1997 生産技術硏究 Vol.19 No.1

The dynamic mechanical properties of thermotropic liquid crystalline polyester (LCP) blends with polystyrene (PS) and Li sulfonated polystyrene (PSSLi) were investigated. It was found that PS forms an immiscible blend with LCP. However, above the matrix T_(g) of the PS, the addition of the LCP increases the modulus of the blend significantly because the LCP acts as filler below its T_(g). In PSSLi/LCP blend system, it was also found that, in the temperature range between two T_(g)s of the ionomer, the LCP acts as filler and thus increases the modulus of the blend. However, the filler effect of the LCP on the modulus decreases rapidly with increasing temperature and disappears above the T_(g) of the LCP. Finally, it was suggested that the PSSLi may be partially miscible with the LCP via ion-dipole interactions between a Li^(+) cation of the PSSLi and a carbonyl group of the LCP.