ABSTRACT
Isocyanurate silane was adsorbed onto E-glass fibers from toluene and ethanol in order to gain a better understanding of the surface processes at the silane-glass interface of composite materials. Use of DRIFT (diffuse reflectance infrared Fourier transform spectroscopy), XPS (X-ray photoelectron spectroscopy), and TGA (thermogravimetric analysis) techniques allowed for the qualitative and quantitative determination of such surface processes. The degree of chemisorption of the silane to the glass surface was investigated by using a sequential washing procedure with solvents characterized by solubility parameters differing from each other. All the analyzing techniques indicated that coupling between the glass and the silane occurred. However, the structure of the silane film depends considerably on the solvent and on the subsequent washing procedure. Copyright 2000 Academic Press.
ABSTRACT
An isocyanurate silane coupling agent effectively attaches to E-glass fibers both from aqueous or CCl4 solution. SEM revealed remarkably different glass surface topographies that were solvent dependent. Application of the coupling agent from CCl4 solution gave rise to unprecendented polymeric bridges between adjacent parallel fibers. The existence of such large bridging structures has only recently been postulated, and it was not thought that such theoretical projections would ever be observed, as polymeric bridging structures typically should collapse in the absence of solvent. Copyright 1997 Academic Press. Copyright 1997Academic Press
ABSTRACT
The adsorption of isocyanurate silane on E-glass fibers has been investigated by scanning electron microscopy, diffuse reflectance Fourier transform infrared spectroscopy (DRIFT), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). The strength of the silane-glass interaction has been related to the extent of removal of the adsorbed species after washing with a range of solvents. The DRIFT and TGA methods both support the conclusion that tetrahydrofuran and acetone, used as washing liquids, adsorb onto the polymerized silane surface. Dichloromethane efficiently removes most of the physisorbed silane, while methanol is less efficient, but promotes a reorientation of the silane. The adsorption and the orientation of the silane is clearly dependent on the relative affinity for the solvent on the one hand and for the glass fiber surface on the other. The XPS N/O ratio and N 1s signal defined both the silane removal and its reorientation on the fiber surface. The morphology of the treated fibers was studied by scanning electron microscopy. Copyright 1997 Academic Press.
