Priming layers and coupling agents

As with adhesives, so with primers. The number of candidate products is enormous in order to fulfil any combination of the following requirements  

Siloxane or silane coupling agents are so termed because they possess a dual reactivity, and are hybrids of silica and of organic materials related to resins. There remains, however, some debate as to the factors affecting the mechanisms by which these materials 

One of the most promising innovations in recent years is the development of hydrophobic Sacrificial Pretreatment Technology (SPT), in conjunction with hydrophobic cold-cure epoxies, to enable underwater bonding(70,83). The energetically-favourable conditions for bonding are established underwater by the application of a water-repellant preferred contaminant to a cleaned or blasted steel 

---