• Polymer(Korea)
• /
• 제27권2호
• /
• pp.152-158
• /
• 2003

Two commercial processing methods have been used to produce poly(methyl methacrylate) (PMMA) marbles; cell molding method and belt molding method. Cell molding method has low productivity and belt molding method has high equipment cost as well as high production cost. A new production method far PMMA marbles using plastic films as molds was studied in this investigation to overcome the shortcomings of cell molding and belt molding method. As plastic film molds for producing PMMA marbles, poly(vinyl acetate) film was used. A methyl methacrylate compound, which has good processability in film molding and shows good mechanical properties after curing, was prepared and used to produce PMMA marbles by film molding method. Properties of the PMMA marbles produced by film molding method were similar to, or higher than, those of commercial PMMA marbles produced by cell molding and belt molding method respectively. The film molding method is considered to have high possibility in commercial application.

• Polymer(Korea)
• /
• 제34권2호
• /
• pp.97-103
• /
• 2010

PMMA was grafted on MWCNT surface in order to prepare conducting film composed of 6FDAbased polyimide/MWCNT. The electrical conductivity of 6FDA-based polyimide/PMMA-g-MWCNT was investigated as a function of PMMA-g-MWCNT content. Dispersion of MWCNT in 6FDA-based polyimide composite film was better than the pristine MWCNT due to the interaction force between PMMA and 6FDA-based polyimide. Electrical conductivity was interpreted by percolation threshold theory. As a result, 6FDA-6FpDA/PMMA-g-MWCNT which have high critical exponents and low critical concentration showed better dispersion than polyimide composite material that contains DABA(diamino benzoic acid).

• Composites Research
• /
• 제30권5호
• /
• pp.288-296
• /
• 2017

The focus of this study is to experimentally investigate the heat dissipation characteristics of poly (methyl methacrylate) (PMMA) composite films with phase change materials (PCM) to resolve heat build-up problems encountered in various electronic devices. In this study, two different types of phase change materials were used to fabricate the composite films by compression molding method and PCM paste sealing method then compared. It was observed in this study that the heat dissipation capability of PCM/PMMA composite films was remarkably enhanced by applying graphite sheet or graphene film into the composite due to their high thermal conductivity. These PCM/ PMMA composite films were attached on the hot spot inside smart phone and tested its surface temperature change according to time. The heat dissipation capability of PCM/PMMA composite film incorporated smart phone was increased 154% and hybrid PCM/PMMA composite film incorporated smart phone was increased 286% over the reference, respectively.

• Journal of the Microelectronics and Packaging Society
• /
• 제12권2호
• /
• pp.181-186
• /
• 2005

We fabricated thin films of polystyrene-block-poly(methyl methacrylate)(PS -b-PMMA) on the self-assembled monolayers(SAM) of 3-(p-methoxyphenyl)propyltrichlorosilane(MPTS) on silicon wafers. Cylindrical nanodomains of PMMA or PS were oriented perpendicular to the surface of silicon wafers due to the neutral affinity of the SAM to PS and PMMA blocks. By selective removal of the PMMA block with UV irradiation and washing, nanoporous films and nanorod assemblies were produced. The nanoporous film can be used for a nanolithographical mask.

• Polymer(Korea)
• /
• 제27권2호
• /
• pp.142-151
• /
• 2003

PMMA panels are made by two fabrication methods; cell molding and belt molding processes. But these methods have disadvantages in productivity and cost. So plastic processing engineers are very interested in developing a new production method for PMU panels using plastic films as molds because the new method can reduce production cost of belt molding method as well as can improve productivity of cell molding method. To give a solution for developing such a new molding method, the effects of melthyl methacrylate compound composition and curing reaction condition on the processability and mechanical strength of PMMA panels were investigated in this study. Poly(vinyl acetate) film was used as molds in producing PMMA panels. To determine an MMA compound showing good processability and good mechanical properties after curing, ingredients and their compositions were optimized step by step. Acrylic acid, as a coupling agent and a modifier, played an important role in increasing mechanical strength of PMMA panels.

• Composites Research
• /
• 제17권4호
• /
• pp.47-52
• /
• 2004

This paper established the procedure to fabricate the MWNT/PMMA nanocomposite by using together with injection molding and film casting processes. The fabrication process made it possible for MWNTs to be well dispersed in the PMMA matrix and also it could maintain the well-dispersed state effectively. And the mechanical material properties and SEM images of the fractural surface were observed. Moreover, a surfactant was used to disperse MWNTs more effectively and mechanical material properties were also investigated.

• Journal of the Korean Vacuum Society
• /
• 제16권3호
• /
• pp.221-226
• /
• 2007

DBR (distributed Bragg reflectors) PSi (porous silicon) composite films displaying dual optical properties, both optical reflectivity and photoluminescence had been developed. DBR PSi samples were prepared by electrochemical etch of heavily doped $p^{++}-type$ silicon wafers (boron doped, polished on the <100> face, resistivity of $0.8-1.2m{\Omega}-cm$, Siltronix, Inc.). Free-standing DBR PSi films were treated with PMMA (polymethyl methacrylate) to produce flexible, stable composite materials in which the PSi matrix is covered with PMMA containing photoluminescent polysiloles. Optical characteristics of DBR PSi/polysilole-impregnated PMMA composite materials exhibit both their photonic reflectivity at 565 nm and photoluminescence at 510 nm, simultaneously. A possible application of this materials will be discussed.

• Proceedings of the Optical Society of Korea Conference
• /
• 한국광학회 2003년도 하계학술발표회
• /
• pp.172-173
• /
• 2003

아조색소를 함유하는 폴리머필름은 Photonics분야에서 그 응용가능성 때문에 집중적인 연구의 대상이 되었다. 부피폴리머필름에서의 아조벤젠유도체의 trans-cis isomerization은 편광홀로그램, optical channel waveguide, reversable optical memory에서 이용되었다. 특히 최근에는 DRl／PMMA의 비공명영역에서 부피홀로그램에서 고회절효율과 Degenerate Four Wave Mixing에서 높은 반사율을 얻어내는 보고가 있었다. (중략)

• Tribology and Lubricants
• /
• 제25권2호
• /
• pp.86-95
• /
• 2009

Adhesion tests were carried out in order to investigate the effect of temperature on the adhesion behavior between a PMMA film and a fused silica lens in the micro scale. For the tests, a microtribometer system was specially designed and constructed. The pull-off forces on the PMMA film were measured under atmospheric condition as the temperature of the PMMA film was increased from 300 K to 443 K and decreased to 300 K. The contact area between the PMMA film and the lens was observed during the test. The adhesion behavior was changed with the change of the PMMA surface state as the temperature increased. In glassy state below 363 K, the pull-off force did not change with the increase of temperature. In rubbery state from 383 K to 413 K, the pull-off force increased greatly as the temperature increased. In addition, the area of contact was enlarged. In viscous state above 423 K, the fingering instability was observed in the area of contact when the PMMA film contacted with the lens. It was also found that the adhesion behavior can be varied with the thermal history of the PMMA film. The residual solvent in the PMMA film could emerge to the PMMA surface due to the heating and reduced the pull-off force.

• Korean Chemical Engineering Research
• /
• 제47권4호
• /
• pp.476-480
• /
• 2009

A polymer composite electrolyte of a blend of poly(methyl methacrylate)(PMMA) and poly(ethylene oxide) (PEO) as a host polymer, the ethylene carbonate as a solvent, and $LiClO_4$ as a salt was studied. The crystallinity of the polymer electrolytes was evaluated using differential scanning calorimeter(DSC). The ionic conductivity of the polymer electrolytes was measured by frequency response analyzer(FRA) method. The effect of PEO/PMMA blend ratios on the ionic conduction in these electrolytes was investigated. The electrolyte films showed a phase separation due to immiscibility of the PMMA with the PEO. The PMMA-rich phase and the PEO-rich phase were produced during a film casting. The ionic conductivity of blend electrolyte was dependent on the content of PMMA and showed the highest value at 20 wt.%. However, when PMMA content exceeds 20 wt.%, the ionic conductivity was decreased due to the slow ionic transport through the PMMA-rich phase.