Metal-based photoinitiators

In situ incorporation of metal based nanoparticles using the newly developed photoinitiating systems... 

IV. OTHER PHOTOINITIATING SYSTEMS BASED ON METAL COMPLEXES... 

The block copolymer produced by Bamford s metal carbonyl/halide-terminated polymers photoinitiating systems are, therefore, more versatile than those based on anionic polymerization, since a wide range of monomers may be incorporated into the block. Although the mean block length is controllable through the parameters that normally determine the mean kinetic chain length in a free radical polymerization, the molecular weight distributions are, of course, much broader than with ionic polymerization and the polymers are, therefore, less well defined,... 

The main requirements of a solvent to be utilized in SRN1 reactions are that (1) it should dissolve both the organic substrate and the ionic alkali metal salt of the nucleophile (2) it should not have hydrogen atoms that can be readily abstracted by aryl radicals (3) there must not be protons that can be ionized by the bases or the basic nucleophiles and radical anions involved in the reaction and (4) it should not undergo ET reactions with the various intermediates of the reaction. In addition to these requirements, the solvent should not absorb significantly in the wavelength range normally used in photoinitiated reactions (300-400 nm). 

XPS has been employed for many years to characterize the surface acid-base properties of catalysts and metal oxides by various methodologies including Fermi level monitoring. We have shown since the early 1990s the potential of XPS in characterizing acid-base properties of conventional polymers using the molecular probe technique. This approach has recently found application in characterizing commercial resins, photoinitiators, and plasma-treated polymers in relation to metallization. 

Chem. Descrip. Benzophenone (50%), 4-methylbenzophenone (50%) Uses Photoinitiator for systems based on acrylic oligomers and monomers, overprint varnishes, clear lacquers for wood, plastic, paper, metal, and optical fiber substrates, flooring coatings, printing inl , adhesives Features High sol. and compat. with various curable systems Properties Colorless to It. yel. clear vise, liq. faint char, odor sol. in most common org. soivs., monomers, prepolymers insol. in water Use Level 0.2-8%... 

CAS 10287-53-3 EINECS/ELINCS 233-634-3 Uses Synergist to improve effectiveness and efficiency of photoinitiators used in UV-curable acrylate-based adhesives, printing inks, photoresist, wood varnishes, and metal coatings Properties Wh. to off-wh. crystalline solid sweet odor m.w. 193.25 m.p. 61-64 C 0.2% max. moisture Toxicology TSCA listed... 

The higher adhesive ability of glycidyl methacrylate when glued to a metal and glass surface has been shown in the study of photoinitiated polymerization kinetics. This result initiated a search for new glue compositions, recipes and techniques. As a possible technique gluing of non-transparent surfaces based on the postpolymerization effect (so-called dark process of the polymerization) has been proposed [13,14],... 

Visible light photoinitiators based on metal salts and complexes have been explored (3,10,12). Some systems generate ionic active centers imless... 

There are, however, several highly reactive vinyl monomers such as 2-(trifluoromethyl) acrylates and 2-cyanoacrylates that undergo anionic polymerizations in the presence of even weak bases. The photoinitiated anionic polymerizations of these monomers have been achieved using a number of photosensitive metal complexes. For example, the irradiation of alkali salts containing the trans-[Cr(NH3)2(NCS)4] anion at wavelengths in the range of 350-532 nm releases the thiocyanate anion (SCN"). As depicted in Scheme 34, the thiocyanate anion is capable of initiating the anionic chain polymerization of ethyl 2-cyanoacrylate. ... 

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