Irradiation acrylated epoxy systems

Acrylated epoxy systems undergo significant changes in thermomechanical properties on standing at room teinperature. Other studies have shown that free radicals are very long-lived in UV-cured systems kept under inert atmospheres, amd that polymerization can continue for extended periods due to the low mobility of the residual unsaturated species at higher conversions. In this study, however, the films were exposed to air immediately after irradiation, which should effectively quench the residue free radicals. 

Silicone acrylates (Fig. 5) are again lower molecular weight base polymers that contain multiple functional groups. As in epoxy systems, the ratio of PDMS to functional material governs properties of release, anchorage, transfer, cure speed, etc. Radiation induced radical cure can be initiated with either exposure of photo initiators and sensitizers to UV light [22,46,71 ] or by electron beam irradiation of the sample. 

UV-curing adhesives are available in a number of chemical systems, most of which are polymer based. These systems include acrylics and acrylates, epoxies, polyurethanes, polyesters, silicones, and vinyl and vinyl esters. The most common UV-curable adhesive is the acrylics. Specially modified acrylic and epoxy adhesives can be cured rapidly by UV radiation. In the case of epoxy adhesives, the adhesives can be pre-irradiated after application to the substrate before closing the bond line. These adhesive systems are offered by most major suppliers. ... 

---