7 сентября, 2015 
Malyar A separate class of acrylic adhesives, not always listed with this family of materials, is the systems that will cure via exposure to light of various wavelengths. Of most interest are the ultraviolet (UV) radiation (below 300 nm wavelength) and, to some extent, the visible range (400 to 700 nm wavelength). These types of adhesives obviously are of utility in bonding substrates that are transparent in the UV and visible regions which is typical of many clear plastics and glass.
To achieve UV cure requires a specific type of initiator called a photoinitiator. These materials are added to the formulations and result in the formation of free radicals when exposed to UV or visible light. Representative compounds that are sensitive to UV light, particularly of 200-300 nm wavelength, are the benzoin ethers, benzophenones, and similar compounds. These and a compound that can activate in the visible region are shown in Fig. 7. When these photoinitiators are exposed to the correct wavelength of light they dissociate into smaller segments to form free radical-containing molecular fragments that ultimately result in a cure much like other acrylic adhesives.
Compositionally, photoinitiated acrylics are much like the formulations already reported in this chapter, but it should be noted that these use special photoinitiators in place of redox or other forms of generating free radicals. The only significant difference is found in the use of acrylate, rather than methacrylate, as the carrier monomer. The acrylates are much more prone to UV initiation and propagation than the methacrylates and are consequently the better choice for the formulators.
Company literature from several adhesive suppliers is currently available that lists UV curable and visible light curing acrylic adhesives as part of their product package. This type of acrylic adhesive is being used successfully in polycarbonate lens bonding.
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