Copolymer containing ketone groups

The photolysis of copolymers containing ketone groups has both academic and practical interest since the way in which the polymeric environment affects the photochemical pathways leads to an understanding of the photodegradation of polymers in which the ketone group is present as an adventitious or intended impurity. Copolymers with vinyl ketones also provide a practical means for preparing plastics with controlled lifetimes as a means of combatting litter problems (1.-3). 

A similar variation in the quantum yield of the Norrish type I process is illustrated in Figure 3 for solid copolymers of ethylene containing three different ketone structures. The ketone groups in the backbone of the polymer chain in ethylene- copolymers show much lower quantum yields than those from the secondary or tertiary structures induced by copolymerization of methyl vinyl ketone and methyl isopropenyl ketone with ethylene. (See Table I, structures I, II and III.) In the latter two cases, the Norrish type I cleavage produces a small radical and a polymer radical, and it seems likely that the small radical has a much greater probability of escaping the cage than when the radicals produced are both polymeric, as in the case of structure I. 

Various copolymers and terpolymers poly(ketone)s containing functional groups (phenolic or phenyl ether substrates) were prepared using ]Pd(dppp)(CH3CN)2] (BF4)2 as the catalyst precursor [124, 125]. Using the same catalytic system meso-genic 1-alkenes were also copolymerized [126]. 

The aliphatic aldehydes and ketones have a weak absorption with a maximum between 270 and 290 nm and a tail which spreads into the region beyond 300 nm. This absorption is attributed to a forbidden (nit ) transition, in which an electron in a nonbonding orbital localized on the oxygen atom is promoted to a delocalized antibonding it orbital distributed over all the carbonyl groups (13). Similar absorption was found for polyolefins containing carbonyl groups in their chain such as ethylene-carbon monoxide copolymer (1 % of CO) (14). 

Photodegradable resins are prepared from a mixture of a copolymer of an unsaturated ketone-group-containing compound with a radical polymerizing monomer and a copolymer of > 1 compound of formula shown... 

In a previous section it was demonstrated that a substantial reduction in quantum yields was observed when the ketone group was included in the backbone of a polyester chain. A similar variation in the quantum yield of the Norrish type-I process is illustrated in Fig. 7 for solid copolymers of ethylene containing... 

Y. Gao, G.P. Robertson, M.D. Guiver, S.D. Mikhailenko, X. Li, S. Kaliaguine, Synthesis of poly(arylene ether ether ketone ketone) copolymers containing pendant sulfonic acid groups bonded to naphthalene as proton exchange membrane materials. Macromolecules 2004, 37(18), 6748-6754. 

By asymmetric reduction of ketone groups in various copolymers Masuda and Stille obtained a copolymer containing either S or R secondary alcohol groups they used a polymeric catalyst containing rhodium and optically active alcohols. 

The synthesis of telehelic methylmethacrylate and styrene oligomers with fruorophenyl ketone end groups is accomplished by the ozonolysis of copolymers containing 4-flurophenyl butadiene units [126],... 

Besides the use of dihalo sulfonated monomers, the Guiver group introduced several commercial sulfonated bisphenol monomers to prepare SPEK polymers. For example, sodium 6,7-dihydroxy-2-naphthalenesulfonate (DFINS) was purchased from Rintech, Inc. and recrystallized before use. The sulfonated poly(arylene ether ether ketone ketone) copolymer containing pendant sulfonic acid groups was... 

---