Browsing by Author "Hsieh, K. H."

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Composites of UHMWPE fiber reinforced PU/epoxy grafted interpenetrating polymer networks
(2007-03-01)
Lin, S. P.
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Han, J. L.
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Yeh, J. T.
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Chang, F. C.
;
Hsieh, K. H.
Several polyurethane-modified epoxy resins (PU/DGEBA-g-IPNs) were synthesized and characterized through a series tests, including differential scanning calorimetry and mechanical property measurements, such as tensile, Izod, bending and shear strengths were investigated in the study. The PU/DGEBA-g-IPNs and neat DGEBA as matrices for UHMWPE fiber-reinforced and aramid fiber-reinforced composites were prepared for comparison of their mechanical properties. The degree of plasma treatment, the polyurethane content, and the type of polyol in the polyurethane within the matrix of the composite were investigated through mechanical and bulletproof testing. (c) 2006 Elsevier Ltd. All rights reserved.
Glass transition temperatures of epoxy modified with pendent nano-organic rigid-rod compounds
(2007-11-01)
Lin, S. P.
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Han, J. L.
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Chen, R. Z.
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Yeh, J. T.
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Chang, F. C.
Pendent nanoscale organic rigid-rod compounds are molecular fiber-like materials that can be used to reinforce the polymer matrix. In this study, 4,4'-diphenylmethane diisocyanate (MDI) was used to covalently connect a number of organic rigid-rod compounds [4'-hydroxyphenyl-4-hydroxy-benzoate (HPHB), phenyl 4-hydroxybenzoate (HPB), 4,4'-isopropylidenediphenol (BSPA), and 2-naphthol (NPT)] to the secondary hydroxyl groups of the epoxy resin. These reactions were monitored using Fourier transform infrared (FTIR) spectroscopy; the products were characterized using nuclear magnetic resonance (NMR) spectroscopy. The glass transition temperatures of the organic rigid-rod compounds modified epoxy resins were investigated through differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). Thermogravimetric analysis (TGA) was used to detect the values of Td and the thermal stabilities of the polymers.
Surface modification and physical properties of various UHMWPE-fiber-reinforced modified epoxy composites
(2007-04-05)
Lin, S. P.
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Han, J. L.
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Yeh, J. T.
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Chang, F. C.
;
Hsieh, K. H.
Two surface modification methods-plasma surface treatment and chemical agent treatment-were used to investigate their effects on the surface properties of ultrahigh-molecular-weight polyethylene (UHMWPE) fibers. In the analyses, performed using electron spectroscopy for chemical analysis, changes in weight, and scanning electron microscope observations, demonstrated that the two fiber-surface-modified composites formed between UHMWPE fiber and epoxy matrix exhibited improved interfacial adhesion and slight improvements in tensile strengths, but notable decreases in elongation, relative to those properties of the composites reinforced with the untreated UHMWPE fibers. In addition, three kinds of epoxy resins-neat DGEBA, poly-urethane-crosslinked DGEBA, and BHHBP-DGEBA-were used as resin matrices to examine the tensile and elongation properties of their UHMWPE fiber-reinforced composites. From stress/strain measurements and scanning electron microscope observations, the resin matrix improved the tensile strength apparently, but did not affect the elongation. (c) 2007 Wiley Periodicals, Inc.
Volume shrinkages and mechanical properties of various fiber-reinforced hydroxyethyl methacrylate-polyurethane/unsaturated polyester composites
(2008-03-01)
Lin, S. P.
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Shen, J. H.
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Han, J. L.
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Lee, Y. J.
;
Liao, K. H.
In this study, two kinds of hydroxyethyl methacrylate-polyurethane (HEMA-PU) were used as volume shrinkage modifiers, and several hydroxyethyl methacrylate-polyurethane modified unsaturated polyester (HEMA-PU/St./UP) resins crosslinked with styrene were synthesized and characterized using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and in terms of their mechanical properties, including their tensile strengths and lzod impact energies. The properties of the HEMA-PU-modified St./UP and St./UP were compared for potential applications as matrices for glass fiber-, aramid fiber-, and UHMWPE fiber-reinforced composites. The effects of the HEMA-PU content and the type of polyol in the HEMA-PU resin matrices of the composites were investigated through testing of their mechanical properties, bulletproof testing, and observations of their morphologies. (c) 2007 Elsevier Ltd. All rights reserved.