ABSTRACT
The origins of commercial anaerobic products can be traced to work done by Burnett and Nordlander at General Electric Corporation in the 1940s. When diacrylate or dimethacrylate monomers based on diethylene glycol or high homologs were heated at 60–80 degree Celsius for some hours while being bubbled with air, oxygen, or ozone, they were converted to materials capable of spontaneously polymerizing at room temperature to form crosslinked polymers possessing adhesive properties. When the anaerobic adhesive was placed on a transition-metal surface under conditions which precluded further contact with oxygen, there was a rapid generation of free radicals; the dissolved oxygen was quickly consumed; polymerization proceeded at a commercially acceptable rate. Anaerobic adhesives (retaining compounds) are now widely used to replace or augment press fits. Typically, a heavy press fit will give shear strength of 4 MPa, whereas the anaerobic retaining compounds can readily give 20 MPa.
