Structural, Spectroscopic, Electronic and Optical Properties of Novel Platinum Doped (PMMA/ZrO2) and (PMMA/Al2O3) Nanocomposites for Electronics Devices

Angham Hazim,Hayder M. Abduljalil,Ahmed Hashim 한국전기전자재료학회 2020 Transactions on Electrical and Electronic Material Vol.21 No.6

This work reports a theoretical study to investigate the electronic structure and optimized geometry for pure PMMA and PMMA doped with ZrO 2 , Al 2 O 3 and Pt nanoparticles for electronics devices. The studied structures are initially relaxed by employing the hybrid functional three parameter Lee–Yang–Parr B3LYP density functional theory at Gaussian 09 package of programs and Gaussian view 5.0.8 program. The PMMA is origin molecule before adding nanoparticles, also this work includes calculations of the electronic properties which contain total energy, energy of highest occupied molecular orbital, energy of lowest unoccupied molecular orbital, energy gap, ionization potential, electronic affi nity, hardness, softness, electronegativity and electrophilic index. The geometrical optimization of PMMA has been found in good agreement with the experimental data due to its relaxed geometrical parameters. The electronic variables, such as, I E , E A , , S, H and ω are computed by the orbital vertical (Koopmans theorem), the nanocomposites studied need small energy to become cation due to ionization potential is smaller than original PMMA, but the electronic affi nity are larger than the original PMMA. So, the hardness for nanocomposites was lowering values as compared with PMMA, therefore all the new molecules are softer, and this reduces the resistance of a species to lose electrons, and the total energy of the studied PMMA was decreased with added nanoparticles to the pure PMMA, total energy is a refl ection of, binding energy of each sheet. The results showed that the nanoparticles added to PMMA reduces the energy gap. All nanoparticles constructed in this work have energy gap lower than that of original PMMA and the (PMMA–ZrO 2 –Pt) nanocomposites have the lowest value of energy gap. These results refer to construct new structures with new electronic properties to use it for modern electronics fields.

First Principles Calculations of Electronic, Structural and Optical Properties of (PMMA–ZrO2 –Au) and (PMMA–Al 2O3 –Au) Nanocomposites for Optoelectronics Applications

Angham Hazim,Hayder M. Abduljalil,Ahmed Hashim 한국전기전자재료학회 2021 Transactions on Electrical and Electronic Material Vol.22 No.2

This study focuses on the quantum mechanical treatment of the geometrical optimization and the electronic structure problems of a nanomaterial PMMA and nanocomposites. The hybrid functional B3LYP/6-31G level of DFT is used to investigate four molecules divided into two groups, they are PMMA as an original basis molecule and (PMMA–Au), (PMMA–Al 2 O 3 –Au), (PMMA–ZrO 2 –Au) nanocomposites as the two group. The DFT calculations have been performed using Gaussian 09 package of programs. The geometrical optimization included both bonds in °A and angles in deg. The calculated electronic properties included the total energy, HOMO and LUMO energies, energy gap, ionization energy, electron affi nity, electronegativity, electrochemical hardness, electronic softness and Electrophilic index. The geometrical optimization of PMMA and nanocomposites has been found in good agreement with the experimental data because of its relaxed geometrical parameters. One of the important results was obtain in this study, is the decreasing of the energy gap. This states that these nanocomposites arethe nearest to semiconductor due to the both HOMO and LUMO levels become more adjacent. These consequences mention to construct new structures with new electronic properties. All nanocomposites need small energy to become cationdue to ionization potential is decrease with addition nanoparticles to the pure PMMA, but the electronic affinity is an increase with with addition nanoparticles to the pure PMMA. The total ground state energy of the PMMA have largest value of total energy compared for other nanocomposites, where E T decreased with addition nanoparticles to pure PMMA. The hardness decrease with addition nanoparticles to the pure PMMA, therefore all the nanocomposites are softer, and this reduces the resistance of a species to lose electrons. Good relax for the structures of the studied PMMA was obtained theoretically, in which, the angles C–C, C=O and C–H in pure PMMA are remain in the same ranges for other nanocomposites. In general, most of the studied nonocomposites direct electronic transition from the valence to conduction band with wave length lies in the range of solar spectrum. The obtained results showed that the (PMMA–ZrO 2 –Au) and (PMMA–Al 2 O 3 –Au) nanocomposites have huge applications in electronics and photo-electronics fi elds.

색조 화장품의 색상에 있어서 Polymethylmethacrylate (PMMA)의 효과

이영아 ( Young A Lee ),김주섭 ( Ju Seub Kim ) 대한화장품학회 2006 대한화장품학회지 Vol.32 No.3

본 연구는 분체를 주성분으로 하는 색조 화장품 제조시 최근 개발된 구상입자의 PMMA를 첨가한 경우와 첨가하지 않은 경우로 나누어 적색계의 착색안료를 넣어 볼연지로 제조한 후 PMMA가 색상변화에 어떠한 영향을 미치는지 비교 분석하는데 그 목적을 둔다. 이러한 연구목적을 달성하기 위해 분체를 주성분으로 하는 파우더 원료에 관해 문헌 고찰을 하였다. 또한 분체안료 Talc, Mica, OMC Talc As, Mica As에 PMMA를 첨가한 경우와 첨가하지 않은 경우로 처방하여 직접 제조한 후, spectrophotometer와 설문조사, digital camera로 촬영하여 비교 평가하였고 SEM을 이용하여 미립자를 비교 분석하였다. 분석결과 PMMA를 첨가하여 제조시 색상이 좀 더 선명하고 짙게 표현되며 촉감도 부드럽게 발리는 것으로 나타났다. 이는 전체 PMMA 비표면적이 커서 oil을 고르게 흡수하기 때문에 색상이 짙고 선명하게 표현되는 결과를 얻을 수 있었다. 그러나 천연안료 Mica는 silicon 처리한 합성안료 Mica As와는 반대의 결과가 나타남에 따라 펄감으로 인해 난반사가 일어날 수 있음을 알 수 있었다. 본 연구 결과 색조 화장품 제조시 구상 미립자 PMMA를 첨가하면 부드럽게 발리는 촉감뿐만 아니라 색상 표현이 좀 더 선명하게 나타나게 해 제품의 색상 표현을 개선할 수 있을 것으로 사료된다. This study is intended to analyze the impact of PMMA on color changes comparatively by making 2 types of cheek color items with red-color pigments: one containing PMMA, which is one of the recently developed circular polymers and used when producing color make-up items that have aero powder as the chief ingredient, and the other without it. To accomplish the purpose, we have reviewed literature on raw materials that have aero powder as the chief ingredient. Also, after making compounds of PMMA and pigments lot aero powder, such as Talc, Mica, OMC Talc As, Mica As, we examined them compared to those without PMMA using spectrophotometer, a questionnaire survey, and Digital camera. Besides, the particles were analyzed using SEM. As a result of the analysis, cosmetics containing PMMA represent more vivid and rich colors, putting on one's face softly. Since the entire specific surface area of PMMA is large enough to absorb oil evenly, it yields vivid and rich colors. But, Mica, one of natural pigments, shows a result as opposed to that of Mica As, one of silicon-compounded pigments, suggesting that pearl effect may possibly causes defused reflection. Based on these findings, it is expected that cosmetics will have more vivid colors, or improved color presentation, as well as the softer sense of touch when a circular polymer of PMMa is added to the manufacturing process of color make-up items.

Barrier Techniques for Spinal Cord Protection from Thermal Injury in Polymethylmethacrylate Reconstruction of Vertebral Body : Experimental and Theoretical Analyses

박춘근,지철,황장회,권성오,성재훈,최승진,이상원,박성찬,조경석,박춘근,강준기,Park, Choon Keun,Ji, Chul,Hwang, Jang Hoe,Kwun, Sung Oh,Sung, Jae Hoon,Choi, Seung Jin,Lee, Sang Won,Park, Sung Chan,Cho, Kyeung Suok,Park, Chun Kun,Yuan, Ha The Korean Neurosurgical Society 2001 Journal of Korean neurosurgical society Vol.30 No.3

Polymethylmethacrylate(PMMA)는 척추 전적출술후에 척추를 재건하기 위해 사용되지만 액체 형태의 PMMA가 응고하면서 발생되는 열은 척수 신경의 열 손상 가능성을 가지고 있다. 이 연구의 목적은 이미 응고된 PMMA sheet가 척수 신경을 보호하는 방어 벽으로서의 열 차단 역할을 할 수 있는지 또한 열손상으로부터 신경을 보호하기 위해 필요한 방어벽의 최소한의 두께를 탐구하는 데 있다. 실험실에서 제 12번째 흉추체 전 적출후의 상태와 동일한 크기와 모양의 정육면체의 용기를 제작하였다. 60ml의 액체형 PMMA를 용기 안에 주입하여 응고하는 PMMA중심부와 세 가지 다른 두께의(제 1 군 : 0mm, 제 2 군 : 5mm, 제 3 군 : 8mm) 이미 응고된 PMMA sheet의 하부(척수의 전면을 의미)에서 온도를 측정하였다. 또한 이 결과에 대한 위의 세 가지 군에 대해 열역학적 분석도 시행하였다. 응고하는 PMMA 덩이의 중심부에서의 온도는 18회의 실험 동안 매우 일정하여($106.8{\pm}3.9^{\circ}C$)이 실험 모델의 재현성을 보여주고 있었다. 방어 벽이 없는 군(제 1 군)에서 척수 신경 전면의 최고 온도가 $60.3^{\circ}C$이었으나 5mm군 (제 2 군)과 8mm군(제 3 군)에서는 각각 $47.3^{\circ}C$와 $43.3^{\circ}C$로 이미 응고된 PMMA는 통계적으로 유의한(p<0.00005) 온도 차단 효과를 보였다. 최고 온도에 도달하기까지의 계산된 시간은 실제 실험치 보다 35%이내의 오차를 보였으나 최고 온도에 대한 열역학적인 계산치는 실제 실험에서 나타난 수치의 1%이내의 오차를 보였다. 이상의 열역학적인 자료를 토대로 볼 때, PMMA를 이용한 척추의 재건술에서 PMMA 방어벽은 척수의 열손상을 방지하는 효과가 있으며, 이 실험에서 가정한 척수의 열손상 역치인 $39^{\circ}C$이하로 척수 온도를 유지하기 위해 필요한 PMMA방어벽의 두께는 10mm정도로 계산되었다. PMMA 방어벽의 임상 적용에 대해서는 추가적인 임상 실험이 필요하다고 사료된다. Objective : Polymethylmethacrylate(PMMA) is often used to reconstruct the spine after total corpectomy, but the exothermic curing of liquid PMMA poses a risk of thermal injury to the spinal cord. The purposes of this study are to analyze the heat blocking effect of pre-polymerized PMMA sheet in the corpectomy model and to establish the minimal thickness of PMMA sheet to protect the spinal cord from the thermal injury during PMMA cementation of vertebral body. Materials & Methods : An experimental fixture was fabricated with dimensions similar to those of a T12 corpectomy defect. Sixty milliliters of liquid PMMA were poured into the fixture, and temperature recordings were obtained at the center of the curing PMMA mass and on the undersurface(representing the spinal cord surface) of a prepolymerized PMMA sheet of variable thickness(group 1 : 0mm, group 2 : 5mm, or group 3 : 8mm). Six replicates were tested for each barrier thickness group. Results : Consistent temperatures($106.8{\pm}3.9^{\circ}C$) at center of the curing PMMA mass in eighteen experiments confirmed the reproducibility of the experimental fixture. Peak temperatures on the spinal cord surface were $47.3^{\circ}C$ in group 2, and $43.3^{\circ}C$ in group 3, compared with $60.0^{\circ}C$ in group 1(p<0.00005). So pre-polymerized PMMA provided statistically significant protection from heat transfer. The difference of peak temperature between theoretical and experimental value was less than 1%, while the predicted time was within 35% of experimental values. The data from the theoretical model indicate that a 10mm barrier of PMMA should protect the spinal cord from temperatures greater than $39^{\circ}C$(the threshold for thermal injury in the spinal cord). Conclusion : These results suggest that pre-polymerized PMMA sheet of 10mm thickness may protect the spinal cord from the thermal injury during PMMA reconstruction of vertebral body.

O2/SF6/CH4 플라즈마를 이용한 플렉시블 Polycarbonate와 PMMA의 건식 식각

주영우,박연현,노호섭,김재권,이제원 한국진공학회 2009 Applied Science and Convergence Technology Vol.18 No.2

There has been a rapid progress for flexible polymer-based MEMS(Microelectromechanical Systems) technology. Polycarbonate (PC) and Poly Methyl Methacrylate (PMMA), so-called acrylic, have many advantages for optical, non-toxic and micro-device application. We studied dry etching of PC and PMMA as a function of % gas ratio in the O2/SF6/CH4 ternary plasma. A photoresist pattern was defined on the polymer samples with a mask using a conventional lithography. Plasma etching was done at 100 W RIE chuck power and 10 sccm total gas flow rate. The etch rates of PMMA were typically 2 times higher than those of PC in the whole experimental range. The result would be related to higher melting point of PC compared to that of PMMA. The highest etch rates of PMMA and PC were found in the O2/SF6 discharges among O2/SF6, O2/CH4 and SF6/CH4 and O2/SF6/CH4 plasma composition (PC: ~350 nm/min at 5 sccm O2/5 sccm SF6, PMMA: ~570 nm/min at 2.5 sccm O2/7.5 sccm SF6). PC has smoother surface morphology than PMMA after etching in the O2/SF6/CH4 discharges. The surface roughness of PC was in the range of 1.9~3.88 nm. However, that of PMMA was 17.3~26.1 nm. 현재 플렉시블 폴리머를 이용한 MEMS (Microelectromechanical Systems) 기술이 빠르게 발전하고 있다. 그 중에서 Polycarbonate (PC), Poly Methyl Methacrylate (PMMA)와 같은 플렉시블 폴리머 재료는 광학적 특성이 우수하고 인체 친화적이며 미세 패턴 제조 공정이 용이하다는 등의 많은 장점을 가지고 있다. 본 연구는 반응성 이온 식각 기술을 이용하여 O2, SF6 그리고 CH4의 삼성분계 가스의 혼합 비율에 따른 PC와 PMMA의 건식 식각 결과 및 특성 평가에 관한 것이다. 준비한 각각의 기판에 포토리소그래피 방법으로 마스크를 형성하여 샘플을 만들었다. RF 척 파워를 100 W, 총 가스 유량을 10 sccm 으로 고정시켜 플라즈마 식각 실험을 실시하였다. 그 결과에 의하면 전체적으로 PMMA의 식각율이 PC보다는 약 2배 정도 높았다. 그 결과는 PC는 PMMA 보다 상대적으로 높은 녹는점을 가지고 있다는 사실과 관계가 있다고 생각한다. 또한 O2/SF6/CH4의 삼성분계 가스와 SF6/CH4, O2/SF6, O2/CH4로 나누었을 때 O2/SF6의 혼합 가스에서 PMMA와 PC의 식각 속도가 가장 높았다 (PC: 5 sccm O2/5 sccm SF6에서 약 350 nm/min, PMMA: 2.5 sccm O2/7.5 sccm SF6에서 약 570 nm/min). SEM을 활용하여 식각된 표면을 분석한 결과 PC는 PMMA보다 상대적으로 식각 표면이 더 매끈하였다. 또한 표면 거칠기 분석 결과 PC의 표면 거칠기는 1.9~3.88 nm이었지만 PMMA의 표면 거칠기는 17.3~26.1 nm로 현저하게 높았음을 확인할 수 있었다.

O₂/SF₆/CH₄ 플라즈마를 이용한 플렉시블 Polycarbonate와 PMMA의 건식 식각

주영우(Y. W. Joo),박연현(Y. H. Park),노호섭(H. S. Noh),김재권(J. K. Kim),이제원(J. W. Lee) 한국진공학회(ASCT) 2009 Applied Science and Convergence Technology Vol.18 No.2

현재 플렉시블 폴리머를 이용한 MEMS (Microelectromechanical Systems) 기술이 빠르게 발전하고 있다. 그 중에서 Polycarbonate (PC), Poly Methyl Methacrylate (PMMA)와 같은 플렉시블 폴리머 재료는 광학적 특성이 우수하고 인체 친화적이며 미세 패턴 제조 공정이 용이하다는 등의 많은 장점을 가지고 있다. 본 연구는 반응성 이온 식각 기술을 이용하여 O₂, SF? 그리고 CH₄의 삼성분계 가스의 혼합 비율에 따른 PC와 PMMA의 건식 식각 결과 및 특성 평가에 관한 것이다. 준비한 각각의 기판에 포토리소그래피 방법으로 마스크를 형성하여 샘플을 만들었다. RF 척 파워를 100 W, 총 가스 유량을 10 sccm으로 고정시켜 플라즈마 식각 실험을 실시하였다. 그 결과에 의하면 전체적으로 PMMA의 식각율이 PC보다는 약 2배 정도 높았다. 그 결과는 PC는 PMMA 보다 상대적으로 높은 녹는점을 가지고 있다는 사실과 관계가 있다고 생각한다. 또한 O²/SF?/CH₄의 삼성분계 가스와 SF?/CH₄, O₂/SF?, O₂/CH₄로 나누었을 때 O₂/SF?의 혼합 가스에서 PMMA와 PC의 식각 속도가 가장 높았다 (PC: 5 sccm O₂/5 sccm SF6에서 약 350 nm/min, PMMA: 2.5 sccm O₂/7.5 sccm SF6에서 약 570 ㎚/min). SEM을 활용하여 식각된 표면을 분석한 결과 PC는 PMMA보다 상대적으로 식각 표면이 더 매끈하였다. 또한 표면 거칠기 분석결과 PC의 표면 거칠기는 1.9~3.88 ㎚이었지만 PMMA의 표면 거칠기는 17.3~26.1 ㎚로 현저하게 높았음을 확인할 수 있었다. There has been a rapid progress for flexible polymer-based MEMS(Microelectromechanical Systems) technology. Polycarbonate (PC) and Poly Methyl Methacrylate (PMMA), so-called acrylic, have many advantages for optical, non-toxic and micro-device application. We studied dry etching of PC and PMMA as a function of % gas ratio in the O₂/SF?/CH₄ ternary plasma. A photoresist pattern was defined on the polymer samples with a mask using a conventional lithography. Plasma etching was done at 100 W RIE chuck power and 10 sccm total gas flow rate. The etch rates of PMMA were typically 2 times higher than those of PC in the whole experimental range. The result would be related to higher melting point of PC compared to that of PMMA. The highest etch rates of PMMA and PC were found in the O₂/SF? discharges among O₂/SF?, O₂/CH₄ and SF6/CH4 and O₂/SF?/CH₄ plasma composition (PC: ~350 ㎚/min at 5 sccm O₂/5 sccm SF?, PMMA: ~570 nm/min at 2.5 sccm O₂/7.5 sccm SF6). PC has smoother surface morphology than PMMA after etching in the O₂/SF?/CH₄ discharges. The surface roughness of PC was in the range of 1.9~3.88 ㎚. However, that of PMMA was 17.3~26.1 ㎚.

유방촬영 시 피폭선량을 줄이기 위한 압박대 재질의 PC, PMMA, Carbon에 대한 연구

홍동희(Dong Hee Hong),정홍량(Hong Ryang Jung) 대한방사선과학회(구 대한방사선기술학회) 2015 방사선기술과학 Vol.38 No.2

유방의 피폭선량을 줄이기 위해 압박대의 재질을 연구하였으며, 재질로는 PC, PMMA, Carbon을 이용한 방사선 투과성 및 선질 등을 측정하였고, 영상을 통한 화질도 분석하여 다음과 같은 결론을 얻었다. Unfors Xi dosimetry 사용 시 방사선 투과율은 압박대를 제거 후 측정한 결과 8.353 m㏉가 나왔으며, PC 6.308m㏉, PMMA 6.223 m㏉, Carbon 7.218 m㏉가 측정되었다. 반가층은 PC 0.375㎜Al, PMMA 0.370㎜Al, Carbon0.360 ㎜Al으로 Carbon, PC, PMMA 순으로 높은 선질과 투과도를 보였다. InLight/OSL NanoDotTM dosimeters 사용 시 압박대를 제거 후 선량계를 위치시켜 측정한 결과 중심부위에서 1.143m㏉, 가장자리에서 12.56 m㏉, PC 중심부위에서 8.990 m㏉, 가장자리에서 10.291 m㏉, PMMA 중심부위에서 8.391 m㏉, 가장자리에서 9.654 m㏉, Carbon 중심부위에서 9.581 m㏉, 가장자리에서 11.313 m㏉가 측정되어 Carbon, PC, PMMA순으로 높은 투과도를 보였다. Image J에서 Pixel 평균값은 압박대를 제거한 후 976.655, PC 831.032, PMMA 819.069, Carbon 897.118로 Carbon, PC, PMMA순으로 높게 측정되었다. This study was designed the band material in order to reduce the exposure pressure of the breast and the material was measured of Radiolucent and radiation properties with a radiation materials of PC, PMMA, Carbon. Also the image quality by image analysis to obtain the following results are below: Unfors Xi dosimetry using radiation transmittance when the results of 8.353m㏉ is measured after re-moval of the cuff, the PC 6.308m㏉, PMMA 6.223m㏉, Carbon 7.218m㏉ were measured respectively. Semi-layer PC 0.375㎜Al, PMMA 0.370㎜Al, with Carbon 0.360㎜Al Carbon, PC, PMMA was higher radiation properties and transparency in order. InLight / OSL NanoDotTM dosimeter was used in the cuff and then removed by placing the dosimeter measured results center on 1.143m㏉, at the edge 12.56m㏉, on the central PC 8.990m㏉, at the edge 10.291m㏉, PMMA center on 8.391m㏉ , the edge 9.654m㏉, on Carbon center 9.581m㏉, 11.313 m㏉ were measured at the edge of Carbon, PC, PMMA showed a high permeability in order. Image Pixel average J is then removed from the cuff 976.655, PC 831.032, PMMA 819.069, Carbon 897.118 Carbon, PC, PMMA was measured by high order.

고압상태의 다양한 용매 내에서 Poly(methylmethacrylate) (PMMA)의 상거동

김제일(Je Il Kim),유기풍(Ki-Pung Yoo),임종성(Jong Sung Lim) 한국청정기술학회 2007 청정기술 Vol.13 No.1

본 연구에서는 variable volume view cell이 장착된 상평형 장치를 사용하여 고압 상태의 다양한 용매 내에서 고분자인 Poly(methylmethacrylate) (PMMA)의 구름점(cloud point)를 측정하였다. 이때 사용된 용매는 chlorodifluoromethane (HCFC-22), dimethylether (DME), 1,1,1-trifluoroethane (HFC-143a), 1,1-difluoroethane (HFC-152a), 1,1,1,2-tetrafluoroethane (HFC-134a) 이였으며, 이들 용대에 CO₂를 첨가한 HCFC-22|CO₂와 DME|CO₂의 이성분계 혼합용매에서 CO₂의 조성 변화가 PMMA의 상거동에 미치는 영향을 살펴보았다. 실험 결과 PMMA는 HCFC-22에서는 340K, 5㎫ 정도의 가장 낮은 온도 압력 조건에서부터 잘 용해되었으며 DME에서는 300K, 28㎫ 정도의 비교적 낮은 온도 압력 범위에서 잘 용해되었으나, 그 밖의 불소화합물인 HFC-143a, HFC-152a, HFC-134a에서는 423,15K, 160㎫의 높은 온도 및 압력 범위에서도 전혀 용해가 일어나지 않았다. 또한, PMMA+HCFC-22 혼합물에 CO₂를 첨가한 PMMA+HCFC-22+CO₂계의 경우는 LCST (lower critical solution temperature)의 상거동을 보였으나 PMMA+DME 혼합물에 CO₂를 첨가한 PMMA+DME+CO₂계의 경우는 UCST (upper critical solution temperature)의 상거동을 보였다. CO₂ 혼합용매 내에서 cloud point 압력은 동일한 온도에서 첨가되는 CO₂의 양에 비례하여 급격히 높아지는 것을 관찰할 수 있었고, 이로부터 PMMA를 SAS (supercritical antisolvent) 법에 의해 미세입자화 할 경우 CO₂가 DME와 HCFC-22에 대한 역용매로 사용될 수 있다는 것을 확인할 수 있었다. 또한 CO₂의 농도를 변화시킴으로써 PMMA의 cloud point를 자유롭게 조절할 수 있다는 것을 알 수 있었다. We measured cloud points of Poly(methylmethacrylate) (PMMA) in various solvents using the high-pressure variable volume view cell apparatus. The solvents used for dissolving PMMA were chlorodifluoromethane (HCFC-22), dimethylether (DME), 1,1,1-trifluoroethane (HFC-143a), 1,1-difluoroethane (HFC-152a) and 1,1,1,2-tetrafluoroethane (HFC-134a), and the effect of CO₂ concentration on the phase behavior of PMMA+HCFC-22+CO₂ system and PMMA+DME+CO₂ system was observed. PMMAwas dissolved well in HCFC-22 from about 340 K, 5㎫ and in DME from about 300 K, 28㎫.However, PMMA was not dissolved at all up to 423.15 K, 160㎫ in the other fluorine compound such as HFC-143a, HFC-152a and HFC-134a. PMMA+HCFC-22, PMMA+HCFC-22+CO₂, and PMMA+DME systems exhibit the lower critical solution temperature (LCST) behavior, however, PMMA+DME+CO₂ system exhibits the upper critical solution temperature (VCST) behavior. In the CO₂ mixture, the cloud point pressure of PMMA was increased dramatically proportional to the amount of CO₂ added, and from this result, it was known that CO₂ could be used as an anti solvent for fabricating PMMA nano-panicles. And the cloud point of PMMA could be controlled by changing the concentration of CO₂.

PLA/PMMA/PBAT 블렌드의 상용성 및 조성에 의한 특성 연구

한지연,차주희,안승재,전한용,Han, Ji-Yeon,Cha, Ju-Hee,Ahn, Seung-Jae,Jeon, Han-Yong 한국섬유공학회 2015 한국섬유공학회지 Vol.52 No.4

The viscoelastic behavior and tensile properties of PLA blends and PLA/PMMA/PBAT blends were measured, and an image analysis was performed, to examine the compatibility of PLA, PBAT, and PMMA. PLA/PMMA blends were found to exhibit a high level of compatibility for all compositions. The thermal stability, modulus, and tensile strength of these blends increased with PMMA content. Also, the glass transition temperature and tensile strength of PLA/PMMA blends varied between the values for neat PLA and PMMA, indicating a high degree of compatibility. On the other hand, ternary blends of PLA, PMMA, and PBAT exhibited a low modulus than PLA/PMMA blends; their compatibility improved with PMMA content because of PMMA acting as a compatibilizer for PLA/PBAT blends.

Highly Conductive Poly(methyl methacrylate) (PMMA)-Reduced Graphene Oxide Composite Prepared by Self-Assembly of PMMA Latex and Graphene Oxide through Electrostatic Interaction

Pham, Viet Hung,Dang, Thanh Truong,Hur, Seung Hyun,Kim, Eui Jung,Chung, Jin Suk American Chemical Society 2012 ACS APPLIED MATERIALS & INTERFACES Vol.4 No.5

<P>We report a simple, environmentally friendly approach for preparing highly conductive poly(methyl methacrylate)–reduced graphene oxide (PMMA-RGO) composites by self-assembly of positively charged PMMA latex particles and negatively charged graphene oxide sheets through electrostatic interactions, followed by hydrazine reduction. The PMMA latex was prepared by surfactant-free emulsion polymerization using a cationic free radical initiator, which created the positive charges on the surface of the PMMA particle. By mixing PMMA latex with a graphene oxide dispersion, positively charged PMMA particles easily assembled with negatively charged graphene oxide sheets through electrostatic interaction. The obtained PMMA-RGO exhibited excellent electrical properties with a percolation threshold as low as 0.16 vol % and an electrical conductivity of 64 S/m at only 2.7 vol %. Moreover, the thermomechanical properties of PMMA-RGO were also significantly improved. The storage modulus of PMMA-RGO increased by about 30% at 4.0 wt % RGO at room temperature while the glass transition temperature of PMMA-RGO increased 15 °C at only 0.5 wt % RGO.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2012/aamick.2012.4.issue-5/am300297j/production/images/medium/am-2012-00297j_0004.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am300297j'>ACS Electronic Supporting Info</A></P>