Photochemical grafting

Abstract We review various methods for the photochemical grafting of organic polymers to various substrates including, organic films, membranes, planar gold, silicon wafers, glass, silica gel, silica nanoparticles, and polydimethylsiloxane micro-channels. An emphasis is placed on photoinitiated synthesis of polymer brushes from planar gold and silicon. 

Photochemical Graft Copolymerization onto Styrene-Butadiene Block Copolymer... 

Surface functionalisation of PE with succinic anhydride followed by derivatisation via ring opening reaction yielded surfaces with different functional groups [128]. The PE films were photochemically grafted with maleic anhydride in vapour phase in a reaction involving benzophenone and acetone at 60 °C for 5 h under UV irradiation with a 400 W mercury vapour lamp. The chemical transformation of PE film bearing succinic anhydride group is schematically presented in Scheme 8. 

The present report extends our work to the photografting of various monomers, using several photo-initiators, onto wood cellu-losic materials. Moreover, it gives the possibility to discuss some problems related to the photochemical grafting. 

Copolymers of 2,3-butanedione-2-< -methacryloyl-oxime with MMA [poly (BOMA-co-MMA)], containing different amounts (7-30 mol%) of side-chain O-acyloxime moieties, have also been used [75] as macro-initiators for the photochemical grafting of styrene and acrylamide in benzene and dioxane solution, respectively,... 

Photochemical grafting of monomers/molecules onto substrates continues to show interest in terms of improving property requirements. Dyes have been effectively photografted onto polypropylene and nylon 6 films using 1,2-diphenyl-2,2-dimethoxyethanone while methacrylic acid and acrylamide have been successfully photografted onto polypropylene sheets using benzophenone as a sensitiser in order to modify the surface of the polymer from a hydrophobic to a hydrophilic one. A styrene-2,2,6,6-tetramethyl-4-piperidinyl... 

Based on the membrane surface properties and the HA properties, various researchers have attempted to change the membrane surface characteristics by surface modification. Different techniques have been performed, such as ion beam irradiation, plasma treatment, redox-initiated graft polymerization, photochemical grafting, and interfacial polymerization (IP). In this chapter, two surface modification techniques, IP and photochemical grafting, are discussed by means of experimental examples. The surface characteristics of the unmodified membrane and the modified membranes are studied and their relationships with irreversible fouling and NF performance are reported. 

The radical addition of 2-mercaptoethanol onto oleic acid, from rapeseed oil, has been done by the photochemical generation of radicals without any photoinitiator (20). The 2-mercaptoethanol is photochemically grafted onto vinyl groups of rapeseed oil by a thiol-ene addition to yield polyols. The higher the content of polyunsaturated fatty chains, the lower the rate of 2-mercaptoethanol grafting was found. 

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