• Title/Summary/Keyword: film crystallinity

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Effect of Acrylic Acid on the Physical Properties of UV-cured Coating Films for Metal Coating (금속코팅용 광경화 코팅필름의 물성에 대한 아크릴산(Acrylic acid)의 영향)

  • Seo, Jong-Chul;Choi, Jun-Suk;Jang, Eui-Sung;Seo, Kwang-Won;Han, Hak-Soo
    • Korean Chemical Engineering Research
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    • v.49 no.1
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    • pp.75-82
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    • 2011
  • Five different composition UV-cured poly(urethane acrylate-co-acrylic acid) (PU-co-AA) films have been prepared by reacting isophorone diisocyanate(IPDI), polycaprolactone triol(PCLT), 2-hydroxyethyl acrylate(HEA), and different weight ratio trimethylolpropane triacrylate(TMPTA) and acrylic acid(AA) as diluents, and characterized using a Fourier transform infrared spectroscopy(FT-IR). The adhesion properties onto the stainless steel, morphology, mechanical hardness, and electrical property of UV-cured PU-co-AA films were investigated as a function of acrylic acid(AA) content. All the PU-co-AA films are structure-less and the molecular ordering and packing density decreased with increasing content of AA due to the flexible structure and -COOH side chains in AA. The crosscut test showed that PU-co-AA films without AA and with low content of AA showed 0% adhesion(0B) and the adhesion of PU-co-AA films in the range of 40-50% AA increased dramatically as the content of AA increases. The pull-off measurements showed that the adhesion force of PU-co-AA films to stainless steel substrate varied from 6 to 31 kgf /$cm^2$ and increased linearly with increasing AA content. The mechanical hardness also decreased as the content of AA increases. This may come from relatively linear and flexible structure in AA and low crystallinity in PU-co-AA films with higher content of AA. The higher AA-containing PU-co-AA films showed higher dielectric constant due to the increase of polarization by introducing AA monomer. In conclusion, the physical properties of UV-cured PU-co-AA films are strongly dependent upon the content of AA and the incorporation of AA in polyurethane acrylate is very useful way to increase the adhesion strength of UV-curable polymers on the stainless steel substrate.

Effects of 1 keV $Ar^+$ ion irradiation on Au films on glass (1 keV $Ar^+$ 이온의 조사가 유리기판위의 금 박막의 미치는 영향)

  • Jang, H. G.;Kim, H. S.;Han, S.;Choi, W. K.;Koh, S. K.;Jung, H. J.
    • Journal of the Korean Vacuum Society
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    • v.5 no.4
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    • pp.371-376
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    • 1996
  • Au films with a thickness around 1600 $\AA$ were deposited onto glass at room temperature by ion beam sputtering with a 5 cm cold-hollow ion gun at pressure $1\times 10^{-6}-1\times 10^{-5}$ Torr. Irradiation of the Au deposited samples was carried out at pressure of $7\times 10^{-6}$ Torr. For the sputter depositions, $Ar^+$ ion energy was 1 keV, and the current density at the substrate surface was 15 $\mu$A/$\textrm{cm}^2$. Effects of 1 keV $Ar^+$ ion dose($I_d$) between $1\times 10^{16}\; and\;2\times 10^{17}\;Ar^+\textrm{cm}^{-2}$on properties such as crystallinity, surface roughness and adhesion, etc. of the films have been investigated. The Au films sputtered by $Ar^+$ ion beam had only (111) plane and the X-ray intensity of the films decreased with increase of $I_d$. The thickness of Au films reduced with Id. $R_{ms}$ surface roughness of the films increased from 16 $\AA$ at as-deposited to 1118 $\AA$ at ion dose= $2\times 10^{17}\;Ar^+\textrm{cm}^{-2}$. Adhesion of Au film on sputtered at $I_d$= $2\times 10^{17}\;Ar^+\textrm{cm}^{-2}$ was 9 times greater than that of Au film with untreated, as determined by a scratch test.

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