• Title/Summary/Keyword: methyl methacrylate

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Photopolymerization of Methyl Methacrylate with p-X-$C_{6}H_{4}SiH_{3}$ (X = F, $CH_3$, $OCH_3$)

  • U, Hui Gwon;Kim, Bo Hye;Jo, Myeong Sik;Kim, Dae Yeong;Choe, Yeong Seop;Gwak, Yeong Chae;Ham, Hui Seok;Kim, Dong Pyo;Hwang, Taek Seong
    • Bulletin of the Korean Chemical Society
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    • v.22 no.12
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    • pp.1337-1340
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    • 2001
  • The bulk photopolymerization of methyl methacrylate (MMA) with para-substituted phenylsilanes such as F-C6H4SiH3 (1), H3C-C6H4SiH3 (2), and H3CO-C6H4SiH3 (3) was performed to produce poly(MMA)s containing the respective silyl moiety as an end group. For all the hydrosilanes, the polymerization yields and the polymer molecular weights decreased, whereas the TGA residue yields and the relative intensities of Si-H IR stretching bands increased as the relative silane concentration over MMA increased. The polymerization yields and polymer molecular weights of MMA with 1-3 increased in the order of 3 < 1 < 2. These hydrosilanes influence significantly upon the photopolymerization of MMA as both chain-initiation and chain-transfer agents.

Photopolymerization of Methyl Methacrylate with 1,4-$C_6H_4(SiH_{3-x}Me_x)_2$

  • U, Hui Gwon;O, Eun Mi;Park, Jong Hak;Kim, Bo Hye;Kim, Yong Nam;Yun, Chan Ho;Ham, Hui Suk
    • Bulletin of the Korean Chemical Society
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    • v.21 no.3
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    • pp.291-294
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    • 2000
  • The bulk photopolymerization of methyl methacrylate(MMA) with bis(silane)s such as 1,4-$C_6H_4(SiH_3)_2$ (1) and 1,4-$C_6H_4(SiH_2Me)_2$ (2) was performed to produce poly(MMA)s possessing the corresponding bis(silyl) moiety as an end group. For the bis(silane)s, while the polymerizaiton yields and the polymer molecular weights decreased, the TGA residue yields and the relative intensities of Si-H IR stretching bands increased as the relative bis(silane) concentration over MMA increased. The polymerizaion yield, polymer molecular weight, and TGA residue yield of MMA with 1 were found to be higher than those with 2. The bis(silane)s appears to influence significantly upon the photopolymerization of MMA as both chain initiation and chain transfer agents.

Phase separation Behavior of P(VDF-co-HFP)/PBA and P (VDF-co-HFP)/P(BA-co-BS) Blends (P(VDF-co-HFP)/PBA 및 P(VDF-co-HFP)/P(BA-co-Bs) 블렌드의 상분리 거동)

  • 홍성돈;김영호;김갑진
    • Proceedings of the Korean Fiber Society Conference
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    • 2003.10b
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    • pp.193-194
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    • 2003
  • 전기활성 고분자인 poly(vinylidene fluoride)(PVDF)를 전기 비활성 고분자와 블렌드시키는 경우 어떤 블렌드계에서는 용융 온도 이상에서 LCST(lower critical solution temperature) 상분리 거동을 나타내는데[1,2], 이때 외부 전장을 가해주면 이들의 상분리 거동에 영향을 미칠 수 있다[3]. PVDF와 블렌딩시켰을 때 LCST 상분리 거동을 나타내는 고분자로는 poly(methyl methacrylate), poly(ethyl methacrylate), poly(1,4-butylene adipate) (PBA) 등이 있다[l,3]. (중략)

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Residue Free Fabrication of Suspended 2D Nanosheets for in-situ TEM Nanomechanics

  • Sharbidre, Rakesh Sadanand;Byen, Ji Cheol;Yun, Gyeong Yeol;Ryu, Jae-Kyung;Lee, Chang Jun;Hong, Seong-Gu;Bramhe, Sachin;Kim, Taik Nam
    • Korean Journal of Materials Research
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    • v.28 no.11
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    • pp.627-632
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    • 2018
  • Two dimensional(2D) crystals, composed of a single layer or a few atomic layers extracted from layered materials are attracting researchers' interest due to promising applications in the nanoelectromechanical systems. Worldwide researchers are preparing devices with suspended 2D materials to study their physical and electrical properties. However, during the fabrication process of 2D flakes on a target substrate, contamination occurs, which makes the measurement data less reliable. We propose a dry transfer method using poly-methyl methacrylate(PMMA) for the 2D flakes to transfer onto the targeted substrate. The PMMA is then removed from the device by an N-Methyl-2-pyrrolidone solution and a critical point dryer, which makes the suspended 2D flakes residue free. Our method provides a clean, reliable and controllable way of fabricating micrometer-sized suspended 2D nanosheets.

Preparation of Alkyl Acrylate and Functional Monomer Multi Core-Shell Composite Particles (알킬 아크릴레이트와 관능성 단량체계 다중 Core-Shell 복합입자의 제조)

  • Choi, Sung-Il;Cho, Dae-Hoon;Seul, Soo-Duk
    • Journal of Adhesion and Interface
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    • v.14 no.1
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    • pp.1-12
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    • 2013
  • Multi core-shell composite particles were prepared by the water-born emulsion polymerization of various core monomers such as methyl methacrylate (MMA), ethyl methacrylate (EMA) and shell monomers such as MMA, EMA, 2-hydroxyl ethyl methacrylate (2-HEMA), glycidyl methacrylate (GMA) and methacrylic acid (MAA) in the presence of different concentrations of sodium dodecyl benzene sulfonate (SDBS). The following conclusions are drawn from the conversion, particle size and distribution, average molecular weight, molecular structure, glass transition temperature with DSC, contact angle after plasma treatment, tensile strength and isothermal decomposition kinetics. In the case of the concentration of 0.02 wt% SDBS, the conversion of MMA core-(EMA/GMA) shell composite particles was excellent as 98.5%. In the case of the concentration of 0.03 wt% SDBS, the particle size of EMA core-(MMA/GMA) shell composite particles was high as $0.48{\mu}m$. We confirmed that 3 points of glass transition temperatures appear for multi core-shell composite particles compared to 1~2 points of glass transition temperatures appear for general copolymer particles. Overall, the adhesion strength of shell composite particles was in the order of EMA/MAA > EMA/2-HEMA > EMA/GMA.

Influences of changes in the Thermal Properties on Pyrolysis of Solid Combustibles (열물성의 변화가 고체 가연물의 열분해에 미치는 영향)

  • Hong, Ter-Ki;Lee, Jong Won;Park, Seul-Hyun
    • Fire Science and Engineering
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    • v.31 no.3
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    • pp.41-48
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    • 2017
  • In order to investigate the influence of changes in the thermal properties of solid combustibles on thermal decomposition, a series of solid pyrolysis experiments were performed using a cone calorimeter specified in KS F ISO 5660-1. In the present study, Poly Methyl Methacrylate (PMMA) which does not produce Char during pyrolysis process was used as solid fuel. Results obtained from cone calorimeter experiments were compared to ones obtained from numerical analysis of Fire Dynamics Simulator (FDS) 1D pyrolysis model adopted with thermal properties of solid fuel as input parameters. Comparisons between experimentally calculated and model-predicted mass loss rate were then made to elucidate the effect of changes in the thermal properties on pyrolysis of PMMA.