Polymer synthesis, photochemical

A. Miyashita, S. Nakano, M. Hirano, and H. Nohira, Negative photochromic polymers. Synthesis and photochemical properties of poly(methyl methacrylate) having spirobenzoselenazolinobenzo-pyran side groups, Chem. Lett., 1993, 501-504. 

N-Benzyl and iV-alkoxy pyridinium salts are suitable thermal and photochemical initiators for cationic polymerization, respectively. Attractive features of these salts are the concept of latency, easy synthetic procedures, their chemical stability and ease of handling owing to their low hygroscopicity. Besides their use as initiators, the applications of these salts in polymer synthesis are of interest. As shown in this article, a wide range of block and graft copolymer built from monomers with different chemical natures are accessible through their latency. 

A. Miyashita, H. Hirano, S. Nakano, and H. Nohira, Diode-laser susceptible photochromic polymers Synthesis and photochemical properties ofpoly(methyl methacrylate) with spiroben-zothiopyrans as side-groups, J. Mater. Chem. 3, 221-222 (1993). 

Neckers, D.C. (1988) Properties of Polymeric Rose Bengals - Polymers as Photochemical Reagents, in Synthesis and Separations Using Functional Polymers (eds D.C. Sherrington and P. Hodge), John Wiley Sons, Inc., New York, pp. 209-26. 

Park et al, reported the synthesis and application of terpolymer bearing cyclic carbonate and cinnamoyl groups. The syntheses of photopolymer with pendant cinnamic ester and cyclic carbonate groups was achieved by the addition reaction of poly(glycidyl methacrylate-co-styrene) with CO2 and then with cinnamoyl chloride. Quaternary ammonium salts showed good catalytic activity for this synthesis. Photochemical reaction experiments revealed that terpolymer with cinnamate and cyclic carbonate groups has good photosensitivity, even in the absence of sensitizer. In order to expand the application of the obtained terpolymer, polymer blends with poly(methyl methacrylate) were also prepared. 

On the other hand, compounds that can be described as trapped or masked disilenes can be viewed as potential monomers for polymer synthesis. The trapped or masked disilene can be liberated from its adduct by chemical or photochemical process. However, even if moderately buUq substituents are present on silicon in such compounds, the liberated disilene combines to afford the thermodynamically favorable cyclized products. Thus, the masked disilene containing isopropyl substituents on silicon affords the cyclotetrasilane [zPr2Si]4 (see Eq. 7.7) [49]. 

Jung, O.-S., and Pierpont, C. G., Photochemical polymers. Synthesis and characterization of a polymeric pyrazine-bridged cobalt semiquinonate-catecholate complex, J. Am. Chem. Soc., 116, 2229-2230 (1994). 

MOR 15] Morris J., Telitel S., Fairfull-Smith K.E. et al, Novel polymer synthesis methodologies using combinations of thermally- and photochemically-induced nitroxide mediated polymerization . Polymer Chemistry, 2015. 

YAG 97] Yagci Y., Endo T., N-benzyl and N-alkoxy pyridinium salts as thermal and photochemical initiators for cationic polymerization , Polymer Synthesis/Polymer Catalysis, Springer, Berhn Heidelberg, vol. 127, pp. 59-86, 1997. 

Paal-Knorr synthesis, 4, 118, 329 Pariser-Parr-Pople approach, 4, 157 PE spectroscopy, 4, 24, 188-189 photoaddition reactions with aliphatic aldehydes and ketones, 4, 232 photochemical reactions, 4, 67, 201-205 with aliphatic carbonyl compounds, 4, 268 with dimethyl acetylenedicarboxylate, 4, 268 Piloty synthesis, 4, 345 Piloty-Robinson synthesis, 4, 110-111 polymers, 273-274, 295, 301, 302 applications, 4, 376 polymethylation, 4, 224 N-protected, 4, 238 palladation, 4, 83 protonation, 4, 46, 47, 206 pyridazine synthesis from, 3, 52 pyridine complexes NMR, 4, 165... 

There are additional factors that may reduce functionality which are specific to the various polymerization processes and the particular chemistries used for end group transformation. These are mentioned in the following sections. This section also details methods for removing dormant chain ends from polymers formed by NMP, ATRP and RAFT. This is sometimes necessary since the dormant chain-end often constitutes a weak link that can lead to impaired thermal or photochemical stability (Sections 8.2.1 and 8.2.2). Block copolymers, which may be considered as a form of end-functional polymer, and the use of end-functional polymers in the synthesis of block copolymers are considered in Section 9.8. The use of end functional polymers in forming star and graft polymers is dealt with in Sections 9.9.2 and 9.10.3 respectively. 

The TT-electron system-substituted organodisilanes such as aryl-, alkenyl-, and alkynyldisilanes are photoactive under ultraviolet irradiation, and their photochemical behavior has been extensively studied (1). However, much less interest has been shown in the photochemistry of polymers bearing TT-electron substituted disilanyl units (2-4). In this paper, we report the synthesis and photochemical behavior of polysiloxanes involving phenyl(trimethylsilyl)-siloxy units and silicon polymers in which the alternate arrangement of a disilanylene unit and a phenylene group is found regularly in the polymer backbone. We also describe lithographic applications of a double-layer system of the latter polymers. 

Apart from the traditional organic and combinatorial/high-throughput synthesis protocols covered in this book, more recent applications of microwave chemistry include biochemical processes such as high-speed polymerase chain reaction (PCR) [2], rapid enzyme-mediated protein mapping [3], and general enzyme-mediated organic transformations (biocatalysis) [4], Furthermore, microwaves have been used in conjunction with electrochemical [5] and photochemical processes [6], and are also heavily employed in polymer chemistry [7] and material science applications [8], such as in the fabrication and modification of carbon nanotubes or nanowires [9]. 

The successful assembly of organic compounds on a solid support represents only part of the challenge in SPOS. After completion of synthetic sequence, the compounds must be cleaved from linkers attached to polymer by a chemical or photochemical reaction, for example, treatment of a polymer-bound compound with acids, bases, nucleophiles, redox reagents, and even photons. Acid-labile linker and amine-cleavable Marshall linker are two major classes of hnkers used in combinatorial synthesis. 

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. 

Novel Synthesis and Photochemical Reaction of the Polymers with Pendant Photosensitive and Photosensitizer Groups... 

This article reports on the synthesis of photosensitive polymers with pendant cinnamic ester moieties and suitable photosensitizer groups by cationic copolymerizations of 2-(cinnamoyloxy)ethyl vinyl ether (CEVE) (12) with other vinyl ethers containing photosensitizer groups, and by cationic polymerization of 2-chloroethyl vinyl ether (CVE) followed by substitution reactions of the resulting poly (2-chloroethyl vinyl ether) (PCVE) with salts of photosensitizer compounds and potassium cinnamate using a phase transfer catalyst in an aprotic polar solvent. The photochemical reactivity of the obtained polymers was also investigated. 

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