Coupling agent organofunctional groups

The organofunctional group (R) in the coupling agent causes the reaction with the polymer. This could be a copolymerization and/or the formation of an interpenetrating network. This curing reaction of a silane-treated substrate enhances the wetting by the resin (Table 9). 

Fig. 5.3. Functions of a coupling agent (a) hydrolysis of organosilane to corresponding silanol (b) hydrogen bonding between hydroxyl groups of silanol and glass surface (c) polysiloxane bonded to glass surface (d) organofunctional R-group reacted with polymer. After Hull (1981).

Silane coupling agents the role of the organofunctional group... 

Silane coupling agents have the structure R—Si—X3, where R represents an organofunctional group and X is generally alkoxy. They are generally applied from water solutions or from organic solvent-water mixtures. In the presence of water, hydrolysis occurs step-wise to form alkoxysilanols, and eventually silane triols. Condensation of the silanols to siloxanes also occurs. Reactions shown schematically below ... 

The examples summarized above are but indicative of the increasing body of evidence in support of the chemical bonding theory, and of the role of the silane organofunctional group in the formation of covalent bonds at the coupling agent/ matrix interphase by reaction or by co-polymerization with the formation of an interpenetrating polymer network. 

Adsorption of alkoxysilanes onto cellulose fibers also holds promise for modification of the cellulose surface. The basic formula of the silane-coupling agents used has an organofunctional group on one side of the chain and an alkoxy group on the other. Abdelmouleh studied the adsorption of several prehydrolyzed alkox-... 

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