Photoinitiators-Multicomponent

Okimato and coworkers [51] have introduced a new multicomponent photoinitiating system composed of the metal-ion-amine CCU for the polymerization of MMA (A > 300 nm). The most active system is FeS04-7H20/... 

In another type of multicomponent photoinitiating system, Okimato and colleage [52] have investigated the Fe -salt/saccharide (SH) system for the photoinitiation... 

Iwai and coworkers [56] have introduced a novel type of multicomponent photoinitiating system for water-soluble monomer (acrylamide, acrylic acid, acrylonitrile, etc). 

This review highlights recent studies of synthetic, covalently linked multicomponent molecular devices which mimic aspects of photosynthetic electron transfer. After an introduction to the topic, some of the salient features of natural bacterial photosynthetic reaction centers are described. Elementary electron transfer theory is briefly discussed in order to provide a framework for the discussion which follows. Early work with covalently linked photosynthetic models is then mentioned, with references to recent reviews. The bulk of the discussion concerns current progress with various triad (three-part) molecules. Finally, some even more complex multicomponent molecules are examined. The discussion will endeavor to point out aspects of photoinitiated electron transfer which are unique to the multicomponent species, and some of the considerations important to the design, synthesis and photochemical study of such molecules. 

Photocrosslinking 61-77 Photoinitiators 63 f., 69 Physical aging 132 Plasticity at the crack tip 135 Plastic zone 135 Poisson distribution 21 Polyaddition, irreversible step 18 Polyamines, addition to polyepoxides 25 f. Polycarboxylic acids 47 Polyepoxides and polyamines 25 f. Polyepoxy-polyamine systems, multicomponent 36... 

In this part, we will present an overview of the radical photoinitiating systems mentioned in the literature. They are classified as one-component (or type I system), two-component (type II systems), and multicomponent photoinitiating systems. According to the chemical structures and the composition of the system, they exhibit a photosensitivity under polychromatic UV lights or UV/visible lights or under laser exposure. Typical absorption spectra of relevant compounds are given in Fig. 10.3. 

Multicomponent Photoinitiating Systems Many multicomponent photoinitiating systems have been proposed so far in order to improve the efficiency of the radical production they are very often used in the design of high-speed photopolymers [222-224]. 

In this chapter, visible light-induced radical polymerization reactions in the 380-800 nm range are reviewed. The role of the absorbing species (dye) and the complete multicomponent photoinitiating systems (PISs) (dye and additives) are then emphasized. The original works on the dye-based PISs that have been proposed over the years are also outlined. However, this chapter is mainly focused on the latest developments, in the 2010-2014 period, and the actual trends of research, in particular the novel perspectives of applications under soft irradiation conditions. 

A variation of UV-NIL developed initially for semiconductor fabrication is known as SFIL and utilizes resist formulations based on UV-initiated free radical generation. The multicomponent resist for SFIL is comprised of an acrylate, a crosslinking diacrylate, a silicon-containing acrylate, and corresponding photoinitiator and surfactant. The resist is commonly... 

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