Phosphonic acid adhesion promoters

In a third procedure, an adhesion promoter of a 3-(ethyl-phosphonic-acid)thiop-hene was applied to the metal surface followed by an electrochemical film preparation [65]. The following procedure was used in this case Mild steel was mechanically polished, then the specimen were treated for 60 minutes in a solution of 3-(ethyl-phosphonic-acid)thiophene. Afterwards, a layer of poly(3-methylthiophene) was formed by electropolymerization in an electrolyte consisting of 0.1 mol 1 3-methylthiophene, 0.1 moll tetrabutyla-mmonium-hexafluorophosphate (N(Bu)4 PFg) in dichloromethane (CH2CI2). 

FUms on these materials can be formed if adhesion promoters are used. With adhesion promoters it is possible to deposit films of conducting polymers on insulators, semiconductors with highly polished surfaces, and corrosive metals. An adhesion promoter consists of an adhesion group, e.g., chloro- or hydroxy silane groups, phosphonic acid groups, which can bond to the surface of the soUd, spacer group, and a monomer molecule as a head group. 

Finally, a thiol-ene reaction was used with vinylphosphonate monomers using CTAs carrying hydrophobic chains, in order to improve the hydrophobic properties of metallic surfaces (Scheme 3.3). The phosphonic acid groups are used to promote adhesion of hydrophobic chains onto the... 

In this chapter, we have summarized three different strategies to use phosphonated copolymers as corrosion inhibitors to protect metals. In the first part, the blends of organophosphorus monomers copolymerized with MMA in a PVDF matrix showed relatively good efficiency. These studies also showed phosphonic acid groups as good adhesion/corrosion promoters, but... 

XPS data gave some indication that a bidentate bond forms between the alkylphosphonate molecules and the oxidized Cu surface. Such hydrophobic phosphonate SAMs could be useful as corrosion inhibitors in micro/nanoelectronic devices and/or as promoters for anti-wetting, low adhesion surfaces.The proposed type of bonding for SAM of a phosphonic acid molecule (OP) is illustrated in Fig. 11.3. It appears that chemisorption of phosphonates on oxidized Cu relies on the hydroxylation of the oxide layer and that the phosphonate undergoes a condensation reaction with surface-bound copper-hydroxyl (-Cu-OH) species to form copper-phosphonate andH20 as a byproduct R-PO-(OH)2+ -Cu-OH R - (OH)OP-O-Cu -+H2O. 

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