• 공업화학
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• 제10권6호
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• pp.923-928
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• 1999

침전중합에 의하여 polycarbonate(PC)/polypyrrole(PPy) 전도성 복합체를 제조하였다. 이때 산화제로서 $FeCl_3$를 단량체로서 pyrrole를 용매로서 chloroform을 사용하였다. PPy의 함량이 증가함에 따라 전기전도도는 증가하였으며 기계적 물성은 감소하였다. PPy의 함량이 25 wt %일때 전기전도도는 0.23 S/cm까지 향상되었다. 전도성 복합체의 대기중의 산화안정성, 전기전도도의 온도의존성, 몰포로지, 그리고 기계적 물성 등을 측정 분석하였다.

• 원예과학기술지
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• 제35권1호
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• pp.79-87
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• 2017

We examined the effect of two greenhouse covering materials (glass or solid polycarbonate sheets) on the light environment and growth of tomato and cucumber plants. Spectral analysis showed that polycarbonate sheets entirely blocked radiation in both the UV - B (300 - 320 nm) and UV - A (320 - 400 nm) ranges, whereas glass transmitted UV - A and was only opaque to UV - B. The transmittance of photosynthetically active radiation (400 - 700 nm) and near infrared radiation (700 - 1100 nm) was higher in polycarbonate than glass. Air and soil temperatures were not significantly different between greenhouses covered with either material. The growth of cucumber plants was slightly affected by covering materials, whereas no significant changes in growth parameters were observed for tomato plants. The color parameters of tomato fruits were affected by the cover material, whereas cucumber fruits showed similar coloration in both glass and polycarbonate greenhouses.

• 공업화학
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• 제10권2호
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• pp.287-292
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• 1999

Polycarbonate (PC)를 matrix로 사용하여 전도성 고분자인 polyaniline (PANI)과의 복합체를 블렌딩 방법에 의하여 제조하였다. 용매로는 chloroform을 사용하였으며 PANI는 전하수송을 가능하게 하고 유기용매에 잘 용해될 수 있도록 camphorsulfonic acid (CSA) 혹은 dodecylbenzenesulfonic acid (DBSA)와 같은 알킬 벤젠 술폰산으로 양성화시켰다. 또한, 전도성 복합체의 전기전도성은 압축성형이 아닌 solution casting법에 의하여 향상시켰다. 아울러 양성화제 유무, PANI의 함량 또는 온도에 따라 전기전도도, 몰포로지 및 인장강도 등을 측정 분석하였다. PANI 착체의 함량이 많을수록 전기전도도는 증가하였으며 알킬사슬이 긴 DBSA로 양성화된 25 wt % PANI 착체의 전도성 복합체의 전기전도도는 3.18 S/cm까지 향상되었다.

• 한국기계가공학회지
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• 제20권4호
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• pp.106-112
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• 2021

Thermoplastic microfluidic devices are used in BioMEMS for medical and biotechnology applications, such as gene extraction, DNA analysis, and virus detection. In this research, a simple fabrication protocol with a commercially available pneumatic hot press is proposed and demonstrated for polycarbonate microfluidic devices. Microfluidic channels with a width of 200 ㎛ and a height of 10 ㎛ were designed and machined onto a brass plate as a mold insert using a CNC milling machine. The resulting microfluidic channels on the mold insert were assessed and found to have an actual width of 198 ㎛ and a height of 10 ± 0.25 ㎛. The microfluidic channels were replicated on a polycarbonate sheet using the proposed replication technique at 146℃ for 20 minutes under a constant load of 2400 kgf. The devices were then naturally cooled to 100℃ while maintaining the same pressure. It was found that the microchannels were successfully replicated in the polycarbonate, with a width of 198 ㎛ and a height of 10.07 ㎛. The proposed replication technique thus offers the rapid mass production of high-quality microfluidic devices at a low cost with a process that, unlike conventional photolithography systems, does not require expensive equipment.

• Elastomers and Composites
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• 제55권1호
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• pp.20-25
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• 2020

The effect of the isocyanate index (NCO index) on the particle size and particle size distribution of a waterborne polyurethane dispersion (WPUD) with polycarbonate-diol was determined. The WPUDs were prepared using a conventional acetone process with polycarbonate-polyol (M_n = 2028), 4,4'-methylenebis(cyclohexyl isocyanate) (H₁₂MDI), 2,2-bis(hydroxymethyl) propionic acid (DMPA), and dibutyltin dilaurate catalyst. At NCO index values below 1.5, the number average particle diameter of the WPUDs significantly increased with the NCO index, whereas the particle diameter slightly varied at higher NCO indexes. The dependency of the WPUD viscosity on the NCO index exhibited similar behavior to that of the particle size. The relative values of the full width at half maximum of the WPUD particle distribution curves at various NCO indexes were not influenced by the NCO index.

• 한국안전학회지
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• 제11권3호
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• pp.3-9
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• 1996

Dynamic fracture characteristics of Polycarbonate WL-RDCB specimen were investigated. The dynamic crack propagation velocities in these specimens were measured by using both high speed camera system and silver paint grid method developed and justified in the INHA Fracture Mechanics Laboratory. The measured crack propagation velocities were fed into the INSAMCR code(a dynamic finite element code which has been developed in the INBA Fracture Mechanics Laboratory) to extract the dynamic stress intensity factors. It has been confirmed that both dynamic crack arrest toughness and the static crack arrest toughness depend on both the geometry and the dynamic crack propagation velocity of specimens. The maximum dynamic crack propagation velocity of Polycarbonate WL-RDCB specimen was found to be dependent on the material property, geometry and the type of loading. The dynamic cracks in these Polycarbonate WL-RDCB specimens seemed to propagate in a successive manner, involving distinguished 'propagation-arrest-propagation-arrest' steps on the microsecond time scale. It was also found that the relat-ionship between dynamic stress intensity factor and dynamic crack propagation velocities might be represented by the typical '$\Gamma$'shape.

• Journal of Korean Vacuum Science & Technology
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• 제2권2호
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• pp.101-106
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• 1998

The poor wear and scratch properties of polycarbonate have limited its application in many fields. In order to improve the wear and scratch properties of polycarbonate we have deposited diamond like carbon (DLC) coatings. The diamond like carbon coatings were made using a high frequency ion beam gun by introducing H2 and CH4 gases. The coatings were characterized with Raman spectroscopy, scanning electron microscope, ellipsometer, microscratch tester and hazemeter. Polymeric hard coating was applied onto the polycarbonate substrate before depositing a DLC coating to investigate the effect of interlayer on the system's failure mode.

• Elastomers and Composites
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• 제39권4호
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• pp.324-329
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• 2004

인계난연제가 함유된 Polycarbonate (PC)/Acrylonitrile-Butadiene-Styrene (ABS) 블렌드에서 사출온도가 상승될 경우 모폴로지 변화와 크레이즈 (Craze) 발생 정도 및 기계적 강도와의 상관관계에 대하여 연구하였다. 사출온도가 상승될 경우 분산상의 합체현상(Coalescence)이 나타났으며 파괴시편에서 크레이즈가 많이 발생하였음을 관찰하였다. 또한 급격한 충격강도의 저하가 발생하였다. 소량의 상용화제를 첨가한 경우 합체현상이 억제됨을 관찰하였으며 크레이즈도 많이 줄여 들었음을 관찰하였다.

• 한국표면공학회지
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• 제55권6호
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• pp.383-389
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• 2022

Natural(outdoor) and accelerated(artificial) weathering tests were performed to investigate their influence on polycarbonate. The polycarbonate materials were prepared of various formulations divided into three batches, with existing, development materials1, development materials2, containing mixture of UV additives. Weathering tests were carried out as outdoor weathering(Seosan, South Korea) and accelerated weathering(xenon-arc), and the results analysis were evaluated based on yellow-index(YI), scanning electron microscope(SEM/EDS), energy dispersive x-ray spectroscopy(XRD), and gel permeation chromatography(GPC). Among the three materials, processing method development materials1 with UV stabilizer was excellent in weathering. This study can provide basic data for standardization of development and performance evaluation on livestock barn roof.

• Bulletin of the Korean Chemical Society
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• 제33권11호
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• pp.3899-3902
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• 2012