• 폴리머
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• 제29권1호
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• pp.19-24
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• 2005

폴리프로필렌(PP)을 포함한 고분자 블렌드에 상용화제를 첨가하여 이축압출기를 통해 시편을 제조하였으며, universal testing machine(UTM), lzod 충격 시험기를 사용하여 물성을 측정하였다. PP/acrylonitrile-butadiene-styrene(ABS) 블렌드의 경우, PP-g-styrene acrylonitrile(PP-g-SAN) 상용화제의 첨가에 의해 기계적 물성이 증가하였으며, ethylene-ethyl acrylate-maleic anhydride(E-EA-MAH-g-SAN) 상용화제의 첨가에 의해서 연성이 증가하는 결과를 나타내었다. PP/ABS/polycarbonate(PC)/Nylon-6,6 블렌드의 경우, ethylene glycidylmethacrylate(E-GMA) 상용화제를 0.5 phr 첨가함에 따라 충격강도가 증가하는 결과를 나타내었다. PP/ABS/PC/Nylon-6,6/poly(methyl methacrylate)(PMMA)/poly(oxymethylene)(POM)/poly(vinyl acetate)(PVC)/poly(butylenes terephthalate)(PBT) 블렌드에서 PP-g-SAN 같은 물리적 상용화제와 E-GMA 와 E-EA-MAH-g-SAN 같은 반응상용화제의 복합적인 작용으로 인해 블렌드의 기계적 물성이 증가된 결과를 나타내었다.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2009년도 학술논문요약집
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• pp.84-85
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• 2009

New approaches for detecting, preventing and remedying environmental damage are important for protection of the environment. Procedures must be developed and implemented to reduce the amount of waste produced in chemical processes, to detect the presence and/or concentration of contaminants and decontaminate fouled environments. Contamination can be classified into three general types: airborne, surface and structural. The most dangerous type is airborne contamination, because of the opportunity for inhalation and ingestion. The second most dangerous type is surface contamination. Surface contamination can be transferred to workers by casual contact and if disturbed can easily be made airborne. The decontamination of the surface in the nuclear facilities has been widely studied with particular emphasis on small and large surfaces. The amount of wastes being produced during decommissioning of nuclear facilities is much higher than the total wastes cumulated during operation. And, the process of decommissioning has a strong possibility of personal's exposure and emission to environment of the radioactive contaminants, requiring through monitoring and estimation of radiation and radioactivity. So, it is important to monitor the radioactive contamination level of the nuclear facilities for the determination of the decontamination method, the establishment of the decommissioning planning, and the worker's safety. But it is very difficult to measure the surface contamination of the floor and wall in the highly contaminated facilities. In this study, the poly(styrene-ethyl acrylate) [poly(St-EA)] core-shell composite polymer for measurement of the radioactive contamination was synthesized by the method of emulsion polymerization. The morphology of the poly(St-EA) composite emulsion particle was core-shell structure, with polystyrene (PS)as the core and poly(ethyl acrylate) (PEA) as the shell. Core-shell polymers of styrene (St)/ethyl acrylate (EA) pair were prepared by sequential emulsion polymerization in the presence of sodium dodecyl sulfate (SOS) as an emulsifier using ammonium persulfate (APS) as an initiator. The polymer was made by impregnating organic scintillators, 2,5-diphenyloxazole (PPO) and 1,4-bis[5-phenyl-2-oxazol]benzene (POPOP). Related tests and analysis confirmed the success in synthesis of composite polymer. The products are characterized by IT-IR spectroscopy, TGA that were used, respectively, to show the structure, the thermal stability of the prepared polymer. Two-phase particles with a core-shell structure were obtained in experiments where the estimated glass transition temperature and the morphologies of emulsion particles. Radiation pollution level the detection about under using examined the beta rays. The morphology of the poly(St-EA) composite polymer synthesized by the method of emulsion polymerization was a core-shell structure, as shown in Fig. 1. Core-shell materials consist of a core structural domain covered by a shell domain. Clearly, the entire surface of PS core was covered by PEA. The inner region was a PS core and the outer region was a PEA shell. The particle size distribution showed similar in the range 350-360 nm.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.332-332
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• 2006

Well difined sulfonated styrene and n-butyl acrylate (nBA) block copolymers were synthesized by CuBr catalyzed living radical polymerization followed by acification by thermolysis. Neopentyl styrene sulfonate (NSS) was polymerized with PnBA macroinitator precursor ($M_{n}=19,500,\;PDI\;<\;1.09$) and CuBr catalyst with N,N,N',N' -pentamethylethyleneamine (PMDETA) to give nBA-NSS block copolymer with narrow polydispersity ($M_{n}=29,900,\;PDI\;<\;1.15$). PNSS segments in the block copolymer were then acidified by thermolysis at $150^{\circ}C$ resulting in polystyrene segments with 100 % sulfonic acid groups.

• 공업화학
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• 제24권2호
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• pp.148-154
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• 2013

UV 경화형 아크릴 점착제는 세상에서 매우 다양한 형태로 이용되는데, 반도체 산업을 기반으로 하는 웨이퍼 제조공정에서도 이용되고 있다. 특히 반도체에 사용되는 웨이퍼가 더욱 얇아짐에 따라, UV 경화형 아크릴 점착제는 더욱 적절한 점착 성능을 요구 받고 있다. 본 연구는 2-EHA (2-ethyl hexyl acrylate), 2-EHMA (2-ethyl hexyl methacrylate), SM (styrene monomer), 2-HEA (2-hydroxy ethyl acrylate), acrylic acid 모노머를 이용하여 hydroxy기를 가진 아크릴 수지점착제를 합성한 후 MOI (methacryloyloxyethyl isocyanate)의 투입량 조절을 통한 경화 특성을 향상시킬 수 있는 부가반응을 시킨 이소시아네이트 변성 아크릴 수지 점착제를 제조하여, 적절한 접착 성능을 알아보고, 수산기 값의 정도와 UV 조사량의 차이에 따라 웨이퍼 제조의 최적화된 조건을 찾았다. 시험 결과 UV 경화형 점착제에서 수산기(Hydroxyl group, -OH)와 이소시아네이트기(isocyanate group, -NCO)의 1 : 1 당량비로 이소시아네이트 경화제를 사용할 경우 수산기값이 클수록, UV 조사 전 박리력이 감소하였다. UV 조사량이 증가할수록 높은 경화 특성 때문에 박리접착 강도는 낮아졌다.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2004년도 제30회 국제세미나
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• pp.19-42
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• 2004

Sizing properties in paper are generally developed through the application of both internal and surface sizes. Rosin, wax, and synthetic sizes including ASA, AKD, and stearic anhydride are and have been used to provide wet-end sizing to paper. In many cases, the use of some of these sizes leads to runnability problems that are inherent in the wet-end operation. Variability in furnish, fines, broke, filler, water chemistry, conductivity, and pH control impacts the wet-end operation. Size press chemicals including starch and polymers such as styrene-acrylic, styrene-maleic, and styrene acrylate emulsions are used in conjunction with internal sizes to improve the paper surface for printing and strength properties, porosity, and opacity improvement. This paper will discuss results from a new, proprietary formulation and process that allows application of sizing chemistry more totally at the size press with reduced emphasis on wet end sizing. Runnability issues are thus minimized at the wet-end, chemical usage is more efficient, and significant cost savings can be realized. Case histories will be presented illustrating the advantages of this new application in commercial trials.

• Macromolecular Research
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• 제17권8호
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• pp.557-562
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• 2009

The free radical polymerization of styrene was initiated with azobis(isobutyronitrile) in the presence of benzene sulfonyl chloride. Analysis of the terminal structures of the obtained polystyrene with $^1H$ NMR spectroscopy revealed the presence of a phenyl sulfonyl group at the ${\alpha}$-end and a chlorine atom at the ${\omega}$-end of each polystyrene chain. The terminal chlorine atom in the polystyrene chains was further confirmed through atom transfer radical polymerization (ATRP) of styrene and methyl acrylate using the obtained polystyrenes as macroinitiators and CuCl/2,2'-bipyridine as the catalyst system. GPC traces of the products obtained in ATRP at different reaction times were clearly shifted to higher molecular weight direction, indicating that nearly all the macroinitiator chains initiated ATRP of the second monomers. In addition, the number-average molecular weights of the polystyrenes increased directly proportional to the monomer conversions, and agreed well with the theoretical ones.

• 핵의학기술
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• 제21권2호
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• pp.65-73
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• 2017

Purpose 3D 프린팅 기술은 3D 스캔이나 모델링을 통하여 적측가공 방식으로 제작하는 기공기술로서 금형 없이 직접 생산이 가능하고 빠른 시간 내에 제작이 가능하여 최근 다양한 산업분야에서 본격적으로 적용되고 있다. 3D 프린팅 기술은 의료분야에 있어, 영상의학 및 방사선 치료분야에서 다양하게 활용되고 있지만 핵의학 분야에서는 관련 연구가 미비한 실정이다. 그러므로 본 연구는 기존에 적용되고 있는 핵의학분야 팬텀과 3D 프린팅 기술로 제작된 텀의 특성을 비교하고 적용 가능성을 평가하는데 목적을 두었다. Materials and Methods 방사선 투과도 변화측정 국제기준 팬텀인 알루미늄(Aluminum) 계단 쐐기(step wedge)를 기준($140mm{\times}62mm{\times}35mm$)으로 PMMA(Poly Methyl Meta Acrylate)와 ABS(Acrylonitrile Butadiene Styrene)재질로 각각 동일한 크기의 팬텀을 제작하였다. PMMA 팬텀은 핵의학 분야에서 주로 적용되는 팬텀의 성분과 동일한 소재로 제작하였고, ABS 팬텀 제작은 3D 프린팅 기술의 액체 기반형의 SLA(Stereo Lithography Apparatus)기법을 사용하여 제작하였다. 본 연구는 SPECT/CT장비 BrightView XCT(Philips Health Care, Cleveland, USA)를 이용하였다. 영상 획득은 Rectangular Flood phantom(Biodex, New York, USA) $^{99m}TcO_4$ 3, 6 mCi와 $^{57}Co$ lood phantom(adqual, New Hampshire, USA) $^{57}Co$ 20 mCi를 이용하여 Aluminum, PMMA, ABS 팬텀에 대해 60 min 리스트모드(List mode)로 획득하였다. 획득한 영상의 분석을 위해 관심영역(ROI)을 설정하여 각 팬텀의 단계별로 평가하였다. Results 방사선원의 종류 및 방사선량에 따라 ABS 팬텀의 계수치는 PMMA 팬텀의 계수치와 유사한 값을 나타내며, 두께의 증가에 따라 선형적으로 감소하였다. Aluminum, PMMA, ABS 팬텀의 선감약계수를 비교했을 때, Aluminum 팬텀의 선감약계수는 나머지 두 팬텀보다 수치가 높았고, PMMA, ABS 팬텀에서는 근사치의 선감약계수가 나타났다. Conclusion 3D 프린팅 기술로 제작된 ABS 팬텀을 기준으로 PMMA 팬텀은 두께가 증가함에 따른 계수치의 변화가 유사하게 선형적으로 감소하였고, 선감약계수도 근사치로 나타내었다. ABS 팬텀의 핵의학적 적용 가능성을 확인할 수 있었으며, 추후 연구를 통해 세부적인 교정치(correction value)를 적용한다면 활발한 적용이 가능하리라 사료된다.

• 대한방사선기술학회지:방사선기술과학
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• 제44권4호
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• pp.343-350
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• 2021

3D printing technology is an additive manufacturing technology produced through 3D scanning or modeling method. This technology can be produced in a short time without mold, which has recently been applied in earnest in various fields. In the medical field, 3D printing technology is used in various fields of radiology and radiation therapy, but related research is insufficient in the field of nuclear medicine. In this study, we compare the characteristics of traditional nuclear medicine phantom with 3D printing technology and evaluate its applicability in clinical trials. We manufactured the same size phantom of poly methyl meta acrylate(PMMA) and acrylonitrile butadiene styrene(ABS) based on the aluminum step wedge. We used BrightView XCT(Philips Health Care, Cleveland, USA) SPECT/CT. We acquired 60 min list mode for Aluminum, PMMA and ABS phantoms using Rectangular Flood Phantom (Biodex, New York, USA) ^99mTcO₄ 3 mCi(111 MBq), 6 mCi (222MBq) and ⁵⁷Co Flood phantom(adq, New Hampshire, USA). For the analysis of acquired images, the region of interest(ROI) were drawn and evaluated step by step for each phantom. Depending on the type of radioisotope and radiation dose, the counts of the ABS phantom was similar to that of the PMMA phantom. And as the step thickness increased, the counts decreased linearly. When comparing the linear attenuation coefficient of Aluminum, PMMA and ABS phantom, the linear attenuation coefficient of the aluminium phantom was higher than that of the others, and the PMMA and ABS phantom had similar the linear attenuation coefficient. Based on ABS phantom manufactured by 3D printing technology, as the thickness of the PMMA phantom increased, the counts and linear attenuation coefficient decreased linearly. It has been confirmed that ABS phantom is applicable in the clinical field of nuclear medicine. If the calibration factor is applied through further research, it is believed that practical application will be possible.

• Korean Chemical Engineering Research
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• 제60권2호
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• pp.295-299
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• 2022

본 논문에서는 범퍼 스키드 플레이트 및 아웃사이드미러 하우징 부품에 적용되는 polypropylene (PP)와 acrylonitrile styrene acrylate (ASA) 소재를 활용하여 무도장 메탈릭 소재 구현에 대해 연구하였다. 금속 효과를 극대화하기 위해 알루미늄 입자의 종류, 크기, 함량을 최적화하였고 웰드 라인을 은폐하기 위해 종횡비가 상이한 하이브리드 알루미늄 입자를 사용하였다. 또한 부품 표면에 발생되는 플로우 마크를 개선하기 위해 유동성을 제어하였으며 사출 해석을 수행하였다.

• 공업화학
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• 제7권4호
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• pp.757-767
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• 1996

폴리(알킬아크릴레이트-g-카프로락톤) 그라프트 공중합체를 합성하였으며, 이것을 폴리카보네이트(PC)/폴리(아크릴로니트릴-부타디엔-스티렌)(ABS) 블렌드의 상용화제로 사용하였다. PC나 ABS와 비상용성인 폴리 알킬아크릴 레이트 주사슬을 갖는 그라프트 공중합체를 사용하였으며 이것을 PC/ABS의 계면에 위치시키는 것을 목표로 하였다. 그라프트 공중합체를 1중량부 포함하는 블렌드물은 충격 강도는 물론 파단 인장 강도에서 아주 향상된 값을 보였으며, 1/8인치 시편에서의 충격 강도 향상이 두드러졌다. 전자현미경에 의한 형태학적인 분석 결과 그라프트 공중합체의 존재가 좀더 매끄러운 PC/ABS 계면을 형성하게 하는 것으로 나타났다.