Surface modifiers glass fibers

A further illustration of IGC as a source of data for acid/base characterization of polymers and of solid constituents of complex polymer systems, is given by Osmont and Schreiber (49), who rate the inherent acid/base interaction potentials of glass fiber surfaces and of polymers by a comparative index, based on the Drago acid/base concepts (SO). The interaction index is conveniently measured by IGC and is shown to differentiate clearly among untreated and variously silane-modified glass fiber surfaces. Conventional methods are used to determine adsorption isotherms for fiber-polymer pairs, and the IGC data ate used to demonstrate the relationship between acid/base interactions and the quantity of polymer retained at fiber surfaces. 

In addition to electrochemical polymerization, reactive monomers can be polymerized onto surfaces by using radio frequency (rf) plasma polymerization [194-197]. In this technique an electric discharge through the vapor forms a reactive plasma that chemically modifies the surface. Examples of applications of rf plasma-polymerized surfaces include the formation of (C2F4) films on fiber optic sensors for detection of volatile organics [198] and the formation of alkylamine surfaces on glass fibers by plasma treatment for subsequent chemical modification [199]. 

K Tsutsumi, Y Abe. Determination of dispersive and nondispersive components of the surface free energy of glass fibers. CoUoid Polymer Sci 267 637-642, 1989. K Tsutsumi, T Ohsuga. Surface characterization of modified glass fibers by inverse gas chromatography. Colloid Polymer Sci 268 38-44, 1990. 

The hand lay-up or spray-up process, used universally for the production of laminar composites incorporating glass fiber reinforcement, is most efficient for the manufacture of large parts, such as boats, bathtubs, tanks, architectural shapes, and recreational accessories. Resins intended for spray-up processes are usually modified with thixotropic additives, such as fumed siHca (1%), to reduce the risk of drainage when appHed over large vertical mold surfaces. Molds are also made from ERP for short-mn products usually surfaced with a tooling gel coat to provide consistent surface quaHty and appearance. 

There are several major areas of interfacial phenomena to which infrared spectroscopy has been applied that are not treated extensively in this volume. Most of these areas have established bodies of literature of their own. In many of these areas, the replacement of dispersive spectrometers by FT instruments has resulted in continued improvement in sensitivity, and in the interpretation of phenomena at the molecular level. Among these areas are the characterization of polymer surfaces with ATR (127-129) and diffuse reflectance (130) sampling techniques transmission IR studies of the surfaces of powdered samples with adsorbed gases (131-136) alumina(137.138). silica (139). and catalyst (140) surfaces diffuse reflectance studies of organo- modified mineral and glass fiber surfaces (141-143) metal overlayer enhanced ATR (144) and spectroelectrochemistry (145-149). 

DNA extraction and purification were traditionally accomplished using organic extraction and ultracentrifugation-based procedures, which are both time-consuming and not easily transferable to the microscale. Newer methods employ solid-phase extraction (SPE) on silica surfaces, glass fibers, modified magnetic beads, and ion-exchange resins—techniques that save time and are also more amenable to chip applications. 

Inverse Gas Chromatography (IGC) was applied to E-glass fiber surfaces modified by various silane coupling agents. Using homologous series of alcohol (acid) and amine (base) vapor... 

A layer with a high specific surface area could be developed on woven glass fiber supports by leaching the nonsilica components out of commercial fabrics in acidic solution [54,62], This treatment created mesoporosity and specific surface areas between 5 and 275 m2 g, depending on the temperature and the contact time with HCI solution. In some cases, the surface of porous glass fibers was modified by titania, zirconia, or alumina to increase the thermomechanical stability and to vary the surface reactivity. The modification was made by impregnation of the porous glass fibers with aqueous solutions of the appropriate salts and subsequent calcinations in air. 

Polysilicate. [DuPont] Polysilicate binder for refractory, ceramic, metal, inorg. fiber, catalyst support, inorg. paint systems, zinc coatings findustrial applic. glass surface modifier. 

Recent investigations [42] incorporate fluoresceinamine into an N.TV -methylenebisacryl-amide copolymer covalently attached to a glass fiber whose surface is modified by plasma deposition followed by acrylamide photopolymerization. The sensor displays a reversible... 

Gas chromatography studies of surface modified silicas provided new insight concerning the adsorption properties of new stationary phases [129]. Inverse gas chromatography (IGC) can be a useful tool to determine the adsorption properties of low surface area solids. The work done by Bakaeva et al. [130] is a good example of IGC use to study low-surface-area-silica glasses. In the cited paper Bakaeva et al. employed IGC to analyze the adsorption of butanol and hexane on E-glass fiber. 

With regard to PET fraction, the potential applications are strongly dependent on its purity (as discussed earlier). Applications like films, fibers, or straps are not recommended when a high concentration of impurities are present In this case, the PET fraction can be employed for structural applications as an engineering polymer with the addition of other components like glass fibers, impact modifiers, and/or nucleating systems. However, reuse of the PET fraction implies that the amount of residual PVC must be kept below 50 ppm to avoid undesirable polymer degradation that results in poor surface appearance and loss of mechanical properties of the manufactured products. 

Another commonly used surface modification method of the reinforcing fibers consists in the treatment with aminoalkylsilanes, for example y-aminopropyltriethoxysilane. Glass fibers, which have been sized in this manner, are incorporated in numerous PPE-containing compositions. In addition, it is always necessary to modify the composition of the thermoplastic matrix to bond the fibers to the matrix. In addition to glass fibers, carbon fibers, e.g., epoxy resin-sized carbon fibers have been used for reinforcement. ... 

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