Silane coupling agent adhesive

F. D. Swanson and S. J. Price, "Chemistry of Urethane Adhesives With Silane Coupling Agents", Adhesives Age, 23, June 1973. 

Fig. 22. Adhesion rating based on flexural sti engths of laminates of poly(styrene) with glass treated with various silane coupling agents vs. solubility parameter of the organo-functional group of the coupling agent. From ref. [117], by permission.

The adhesion promotion of an organic matrix to an inorganic substrate using a silane has been studied to model the structure of the created interphase [64-66]. The polymer/silane interphase is influenced by the solubility parameter of both the silane coupling agent and the polymer. More interdiffusion occurs when the solubility parameters of the polymer and the silane closely match together. It is believed that this model can be applied to silicone adhesive/solid substrate system. 

Jones, F.R., Interfacial aspects of glass fibre reinforced plastics. In Jones, F.R. (Ed.), Interfacial Phenomena in Composite Materials. Butterworths, London, 1989, pp. 25-32. Chaudhury, M.K., Gentle, T.M. and Plueddemann, E., Adhesion mechanism of poly(vinyl chloride) to silane primed metal surfaces. J. Adhes. Sci. Technol, 1(1), 29-38 (1987). Gellman, A.J., Naasz, B.M., Schmidt, R.G., Chaudhury, M.K, and Gentle, T.M., Secondary neutral mass spectrometry studies of germanium-silane coupling agent-polymer interphases. J. Adhes. Sci. Technol., 4(7), 597-601 (1990). 

Various additives and fillers may be employed. Calcium carbonate, talc, carbon black, titanium dioxide, and wollastonite are commonly used as fillers. Plasticizers are often utilized also. Plasticizers may reduce viscosity and may help adhesion to certain substrates. Thixotropes such as fumed silica, structured clays, precipitated silica, PVC powder, etc. can be added. Adhesion promoters, such as silane coupling agents, may also be used in the formulation [69]. 

Other aspects of interfacial science and chemistry are examined by Owen and Wool. The former chapter deals with a widely used chemistry to join disparate surfaces, that of silane coupling agents. The latter chapter describes the phenomenon of diffusion at interfaces, which, when it occurs, can yield strong and durable adhesive bonds. Brown s chapter describes the micromechanics at the interface when certain types of diffusive adhesive bonds are broken. The section on surfaces ends with Dillingham s discussion of what can be done to prime surfaces for adhesive bonding. 

The formation of these polar groups contributes increased adhesion. Observation of disappearing vinyl groups in the silane coupling agent and of the formation of polystyrene in the silica by FTIR analysis (Fig. 15) have confirmed the occurrence of a reaction between the polymer and the silane coupling agent [77]. 

Ethylene-vinyl acetate Fetterman [37] reinforced compounded ethylene-vinyl acetate (EVA) copolymer by using short hbers and found that silane coupling agents were effective at establishing improved hber-matrix adhesion. Das et al. [38] prepared carbon fiber-filled conductive composites based on EVA and studied the electromagnetic interference shielding effectiveness of the composites. 

Liquid rubbers In order to improve the flexibihty of short glass fiber-reinforced epoxy composites, Kaynak et al. [53] modified the epoxy resin matrix with hydroxyl-terminated polybutadiene (HTPB) liquid mbber. A silane coupling agent was also used to improve the interfacial adhesion between glass fibers and epoxy matrix. However, Humpidge et al. [54] reported some unique processing problems for the resulting pasty mixmres when short textile fibers were incorporated in a hquid mbber medium. 

Injecting epoxy, furan, or furan-formaldehyde resins into poorly consolidated formations to consolidate them was a common sand control practice for thin highly productive formations (44-46). Organic solvents (46) and silane coupling agents (47) are used to promote adhesion of the resin to the rock surface. Excess resin is flushed deeper into the formation to minimize resin hardening in the flow channels since this would reduce formation permeability. 

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