✍ Scribed by Zoltán Demjén; Béla Pukánszky; Enikő Földes; József Nagy
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range, thus surface treatment is the obvious way to modify A study of eight silane coupling agents showed very different interaction.
effect of these compounds on the mechanical properties of PP/ Component adhesion and thus properties can be optimized CaCO 3 composites. The application of aminofunctional silane cou-only if the mechanism of interaction as well as the structure pling agents resulted in the reactive coupling of the two inactive and properties of the interphase are known. Surface coverage components leading to increased strength and decreased deformmust be optimized, too. Silane coupling agents do not adsorb ability. A detailed study of the interaction between CaCO 3 and in a single layer on the filler surface but form an interphase the various coupling agents was carried out in order to find an with chemisorbed and physisorbed layers (8-10). The role explanation for the strong coupling effect. The amount of coupling agent creating a monolayer coverage was determined by a dissolu-of the physisorbed layer in the reinforcement process is not tion method for each coupling agent. The obtained values changed known. Contradictory results are reported about its thickness between 0.3 and 1.0 wt% calculated for the CaCO 3 . An attempt and effect on the mechanical properties of the composites was made to determine the orientation of the adsorbed molecules (11). An optimum concentration seems to exist for each to the filler surface. Most of the coupling agents are oriented perpolymer/filler system, where mechanical properties reach a pendicularly to the surface with the exception of a methacryl funcmaximum value (7, 12). The structure and composition of tional silane compound. Possible interactions between hydrolyzed the interphase formed by the coupling agent continuously or condensed silane coupling agents and the filler were studied by change from the surface of the filler towards the polymer Fourier transform infrared spectroscopy using transmitting matrix (10, 13, 14). The subsequent layers of the silane (FTIR-TS) and diffuse reflectance (DRIFT) modes, as well as form a network structure, which obviously influences the gel permeation chromatography (GPC). The results showed that bulky organofunctional groups form a caged, polycyclic, low-mo-mechanical performance of the composite (8,(15)(16)(17). The lecular-weight structure on the surface, while silanes with smaller structure of the polysiloxane network can be affected by groups tend to condense into open, ladder type, high-molecularseveral factors like the conditions of the treatment (solvent, weight polysiloxane chains. Polymer/filler adhesion, however, dethe concentration of the solution, the pH of the aqueous pends primarily on the chemical character of the organofunctional slurry), the specific surface area of the filler, its chemical group. Aminofunctional silane coupling agents adhere well to the functionality, as well as the alkoxy-and organofunctionality filler surface and react also with the polymer. In the case of similar of the silane (18). If the silane contains long-chain alkyl functionality the size of the organofunctional group determines groups, low-molecular-weight polycyclic structures form; the strength of the adhesion. ᭧ 1997 Academic Press short chains favor the formation of an open, high-molecular-
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## Abstract The photelectron spectra of five different liquid silanes were measured. Their C 1s spectra and measured compositions were all consistent with the theoretical formula of these compounds. Subsequently, E‐glass fibers were exposed to dilute aqueous solutions of these silanes, and their ad