Copolymer photophysical processes

Photophysical Processes in PET and Model Compounds. The photophysical processes in many polymer, copolymer, and polymer-additive mixtures have been studied (17. 18. 19). However, until recently, few investigations have been made concerning the photo-physical processes available to the aromatic esters in either monomeric or polymeric form. 

Photophysical Processes and Photodegradation of Poly(ethylene terephthalate-co-2,6-naphtha1enedi carboxyl ate) Copolymers. We have recently reported the photophysical processes and the photo-degradative behavior of Doly(ethylene terephthalate-co-2,6-naphthalenedicarboxyl ate), PET-2,6-ND, copolymer yarns containing 0.5 - 4.0 mole percent 2,6-naphthalenedicarboxyl ate, 2,6-ND (1) and the parent naphthalenedicarboxyl ate monomer, Figure 3 and 4. 

Photophysical Processes in Pol,y(ethy1eneterephthalate-co-4,4 -biphenyldicarboxyl ate) (PET-co-4,4 -BPDC). The absorption and luminescence properties of PET are summarized above. At room temperature the absorption spectrum of PET-co-4,4 -BPDC copolymers, with concentrations of 4,4 -BPDC ranging from 0.5 -5.0 mole percent, showed UV absorption spectra similar to that of PET in HFIP. The corrected fluorescence spectra of the copolymers in HFIP exhibited excitation maxima at 255 and 290 nm. The emission spectrum displayed emission from the terephthalate portion of the polymer, when excited by 255 nm radiation, and emission from the 4,4 -biphenyldicarboxylate portion of the polymer when excited with 290 nm radiation. 

Photophysical Processes in PET-4,4 -SD Copolymers. PET-4,4 -SD copolymers have UV absorption spectra similar to that of PET homopolymer in HFIP solution. Band maxima were exhibited at about 290, 245, and 191 nm in all the polymers. 

Photochemical and photophysical processes in cellulose and related compounds have received considerable attention during the last decades, resulting in research work concerned with the improvement of cellulosic materials via physical and chemical modifications. One method was to apply a copolymer between the cellulose and a synthetic polymer which are generally grafted by free radical reactions. 

Phillips, D., Roberts, A. J., Soutar, I. Transient decay studies of photophysical processes in aromatic polymers, III. Concentration dependence of excimer formation in copolymers of acenaphthylene and methyl methacrylate. Eur. Polym. J. 17,101 (1981)... 

The photo-oxidative degradation of polypropylene and stabilization by hindered amines has been reviewed. A study has appeared of the effect of P-carotene on the photoreactivity of anthracene in hexane solution and a kinetic scheme has been proposed to account for the photochemical and photophysical processes that occur on irradiation at 365 nm. Quenching rate constants have been determined between /S-carotene and singlet oxygen. Some characteristics have been communicated of the sensitized photo-oxidation of abietic acid contained in a vinyl butyl ether-butyl methacrylate-methacrylic acid copolymer. At 400 nm... 

R.B. Fox, T.R. Price, R.F. Cozzens, and J.R. McDonald, Photophysical processes in polymers. IV. Excimer formation in vinylaromatic polymers and copolymers, J. Chem. Phys. 57, 534 (1972). C. David, W. Demarteau, and G. Geuskens, Energy transfer in polymers II Solid polyvinyl naphthalene benzophenone system and copolymers vinylnaphthalene yinylbenzophenone, Eur. Polym. J. 6, 1397 (1970). 

A. Rivaton, B. Mailhot, S. Robu, M. Lounad, P. Bussiere, and J.-L. Gardette. Photophysical processes and photochemical reactions involved in poly(M-vinylcarbazole) and in copolymers with carbazole units. Polym. Degrad. Stabil, 91(3) 565-572, March 2006. 

Fox RB, Price TR, Cozzens RF, and McDonald JR. Photophysical processes in polymers. IV. Excimer formation in vinylaromatic polymers and copolymers. J. Chem. Phys. 1972 57 534-541. 

The largest body of experimental work on the photochemistry of solid polymers relates to the study of the photolysis of homo- and copolymers of vinyl ketones. In early work, Guillet and Norrish (20) and Wissbrun (21) showed that polymeric ketones such as poly(methylvinyl ketone) and poly(methylisopropenyl ketone) underwent the same classical photochemical reactions as their low-molecular-weight analogs. The photophysical and photochemical processes which occur are summarized below ... 

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