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- Coupling methods (2)
- Plasma modification (2)
- Adhesion promoting interlayers (1)
- Adhesion promotion (1)
- Attenuated total reflectance-Fourier transorm infrared spectroscopy (1)
- Carbon fiberepoxy resin laminates (1)
- Chemical conversion of functional groups (1)
- Chemical reduction of functional groups (1)
- Copolymers (1)
- Electrospray ionization (ESI) (1)
- Ionization mass spectrometry (1)
- Layer topography (1)
- Liquid adsorption chromatography (1)
- Liquid chromatography (1)
- MALDI (1)
- MALDI-TOF-MS (1)
- Matrix-assisted laser desorption (1)
- Metal-polymer interactions (1)
- Metal-polymer systems (1)
- Oxygen low-pressure plasma treatment of polymers (1)
- PET (1)
- Peel strength (1)
- Plasma (1)
- Plasma polymers with functional groups (1)
- Poly(ethylene terephthalate) (1)
- Polyethylene (1)
- Polypropylene (1)
- Spacers (1)
- Thin polymer layers (1)
- X-ray photoelectron spectroscopy (1)
- r.f. pulsed plasma (1)
Thin coatings of poly(acrylic acid) (PAA) and poly(hydroxyethylmethacrylate) (PHEMA) were deposited onto carbon fibers by means of the electrospray ionization (ESI) technique in ambient air. These high-molecular weight polymer layers were used as adhesion promoters in carbon fiberepoxy resin composites. Within the ESI process, the carbon fibers were completely enwrapped with polymer in the upper 10 plies of a carbon fiber roving. As identified with scanning electron microscopy also shadowed fibers in a bundle as well as backsides of fiber rovings were pinhole-free coated with polymers (electrophoretic effect'). Under the conditions used, the layers have a granular structure. Residual solvent was absent in the deposit. PAA and PHEMA films did not show any changes in composition and structure in comparison with the original polymers as analyzed by X-ray photo-electron spectroscopy and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Single-fiber pullout tests of coated fibers embedded in epoxy resin showed significantly increased interfacial shear strength. It is assumed that chemical bonds between carbon fiber poly(acrylic acid) and epoxy resin contribute significantly to the improved interactions.
The influence of different types of low and atmospheric pressure plasma on poly(ethylene terephthalate) (PET) has been studied in terms of changes in molar mass and molar mass distribution. Apart from a variation of plasma gases (oxygen, helium) different types of plasma (microwave, radio frequency, corona discharge) were used for the plasma surface modification. The changes in molar mass and types of functional end groups of lower molar mass products were investigated by means of matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOFMS), whereas the high-molar mass fraction was analyzed by means of size-exclusion chromatography (SEC). The formation of crosslinked products during exposure to a helium plasma, which emits preponderately energy-rich and intense ultraviolet radiation, was proved by means of thermal field-flow fractionation (ThFFF). This method combined with a multiangle laser light scattering (MALLS) detector allows detection of weakly crosslinked polymers and microgels. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1639-1648, 1998
Polymer surfaces can be finished with functional groups upon exposure to a plasma. Species of the plasma gas are attached at surface carbon atoms, forming functional groups of different composition. To produce a modified polymer surface with a high density and homogeneity of hydroxyl groups only, the oxygen-plasma-formed oxygen functional groups were chemically reduced by diborane and LiAlH4 with yields of 10 to 11 OH groups per 100 carbon atoms in the 3 to 5 nm near-surface layer as detected by X-ray photoelectron spectroscopy (XPS). The identification of hydroxyl groups was performed by means of attenuated total reflectanceFourier transform infrared spectroscopy and XPS.