DURABILITY OF ADHESIVE-BONDED JOINTS EMPLOYING ORGANOSILANE COUPLING AGENTS

One of the major problem areas that continues to confront the use of structural adhesives in engineering applications concerns the effects of atmospheric moisture which, under certain circumstances, can seriously impede the load-bearing capacity of a bonded component. Various approaches can be used in an attempt to alleviate moisture-related problems, one being the use of organosilanes, particularly when employed as pre-bond primers. Since experience has shown that organosilanes perform best in dilute solution, a great deal of the research conducted in the authors' laboratory, much of which is presented here, has been concerned with the study of organosilane solutions as primers. Experimental parameters shown to be of importance include the nature of the solvent employed, the solution age and pH, and the conditions under which the silane film is subsequently dried. The results suggest that failure to study experimental parameters such as these could provide no significant improvements in adhesive joint durability and thus provide a misleading impression of the beneficial qualities of organosilane coupling agents. © 1990.