Photo-curing adhesives

Several systems may be important in the future as aerospace adhesives, electronic adhesives, high solid adhesives, hot melt adhesives, and photo-cured adhesives. We believe that future adhesives will be less likely to pollute the environments and will somehow save energy. 

In brief, photo-curing systems may offer interesting adhesive properties which have not been obtained with conventional adhesives. 

The potential of using extrinsic (fluorescent) probes for monitoring the initial stages of oxidation was explored for the photo-oxidation of a UV-cured aliphatic polyurethane-acrylate-based adhesive [68]. The two probes investigated were p-dimethylamino salicylic acid (p-DASA) and 2, 7 -difluorescein (Oregon Green... 

In the case of a photoresist, the ultimate definable feature size together with the ability of the material to withstand either chemical etchants or plasma environments determines the domain of utility. The feature size is in turn determined by the wavelength required for exposure, the sensitivity and contrast of the resist, and the dimensional stability of the material during exposure, development, and subsequent processing. Adhesion of the resist to the substrate is critical both for patterning and use, and adhesion can be affected by surface preparations, and by residual stresses developed during deposition and cure. While photo-imagable polyimides have been introduced, their principal intended application is as a component of the finished part, either as passivant or interlevel dielectric (see below). 

Inhomogeneities [137] and traveling waves of the initiator [138] have been investigated during the formation of PMMA, and the spatial variation and the dynamics of a photo-induced polymerization have been followed in another example [139]. The curing of adhesives [112], and the influence of embedded fibers on the loeal polymerization rates of epoxy resins [140, 141], have been investigated in a similar way. A related subjeet is the vulcanization process of elastomers (cf. Section 5.2.2). 

Keywords Acrylates Crosslinking Dual cure Epoxides Glass laminates Interpenetrating polymer networks Isocyanates Photo initiated cationic polymerisation Photoinitiators Photopolymerisation Pressure sensitive adhesives Release coatings Structural adhesives Thiol/polyene UV radiation curing Vinyl ethers. 

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