@article { ISI:000232341100010, title = {Photodegradation of ethylene/propylene/polar monomers co- and terpolymers. I - Prepared by group 4 catalyst systems}, journal = {Journal of Macromolecular Science-Pure and Applied Chemistry}, volume = {A42}, number = {9}, year = {2005}, month = {SEP}, pages = {1259-1270}, publisher = {TAYLOR \& FRANCIS INC}, type = {Article}, address = {325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA}, abstract = {

The photooxidative degradation behavior of polyethylene, its copolymers (propylene/polar monomers) and terpolymers, synthesized by a group 4 catalyst system, has been studied by Fourier transform infrared spectroscopy and confirmed with scanning elecrton microscopy for morphological changes. The kinetics of photodegradation has also been studied. Surface damage caused by polychromatic (\>= 290 nm) at 55 degrees C in air is presented in different micrographs. The rate of photodegradation is very fast in terpolymers containing polar monomers as compared with copolymers and polyethylene. Morphological study of these photodegraded samples showed a very good relation with photodegradation results.

}, keywords = {functional polyolefins, Photodegradation, UV irradiation}, issn = {1060-1325}, doi = {10.1080/10601320500189570}, author = {Fernandes, Susete N. and Correia, Sandra and Prasad, A. V. and Reddy, K. R. and Rana, S. and Lonkar, Sunil P. and Marques, Maria M. and Singh, R. P.} } @article { ISI:000245141300053, title = {Photodegradation of ethylene/propylene/polar monomers, Co-, and terpolymers. II. prepared by Ni catalyst systems}, journal = {Journal of Applied Polymer Science}, volume = {104}, number = {3}, year = {2007}, month = {MAY}, pages = {1783-1791}, publisher = {WILEY-BLACKWELL}, type = {Article}, address = {COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA}, abstract = {

The copolymers of ethylene/propylene as well as their terpolymers with polar monomers were prepared by Ni-catalyst systems and their photodegradation behavior was studied by Fourier transform infrared spectroscopy. The polar monomers used to synthesize co- and terpolymers of ethylene/propylene/polar monomer were 5-hexen-1-ol, 10-undecen-1-ol, acrylamide, methylmethacrylate, acrylonitrile, and methylvinyl ketone. The morphological changes of the irradiated samples were determined by scanning electron microscopy. The photodegradation kinetics has also been studied. The surface damage caused by polychromatic irradiation (lambda \>= 290 nm) at 55 degrees C in atmospheric air is presented in different micrographs. The rate of photo-oxidative degradation is very fast in terpolymers containing polar monomers as compared with copolymers and homopolymers. The morphological study of the photodegraded samples showed a very good correlation with the photodegraded results. (c) 2007 Wiley Periodicals, Inc.

}, keywords = {copolymerization, Ethylene, Photodegradation, polar monomers, propylene}, issn = {0021-8995}, doi = {10.1002/app.25828}, author = {Fernandes, Susete N. and Correia, Sandra and Matos, Ines and Marques, Maria M. and Rana, Sravendra and Kumar, Bijandra and Gupta, M. K. and Singh, R. P.} } @article { ISI:000319275700021, title = {Copolymerization of ethylene with unsaturated alcohols and methylmethacrylate using a silylated alpha-diimine nickel catalyst: molecular modeling and photodegradation studies}, journal = {Journal of Applied Polymer Science}, volume = {129}, number = {4}, year = {2013}, month = {AUG}, pages = {1820-1832}, publisher = {WILEY-BLACKWELL}, address = {111 RIVER ST, HOBOKEN 07030-5774, NJ USA}, abstract = {

In this article, the experimental results obtained in the copolymerization of ethylene with polar monomers using a silylated -diimine nickel catalyst are described and compared with those obtained with a non-silylate similar one. The results show that the introduction of a siliyl group in the para-position of the imine moiety turns the catalyst less sensitive toward polar functionalities. However, the reactivity observed in copolymerization reactions was found to be reduced both the global polymerization and incorporation rates. Molecular modeling calculation allowed us to understand both the preferred insertion mode and the intermediate product structures for E/MMA copolymerization. Photodegradation studies showed that the presence of polar groups in the copolymers increases their rate of oxidation and turn them more easily degradable. The stabilization performed by Tinuvin 770 showed that for long-exposure times, it is not very effective regardless it is only mixed or grafted to the copolymer. (c) 2012 Wiley Periodicals, Inc.

}, keywords = {ageing, copolymers, Degradation, grafting}, issn = {0021-8995}, doi = {10.1002/app.38889}, author = {Matos, Ines and Fernandes, Susete N. and Liu, Hua-Rong and Tevtia, Amit K. and Singh, R. P. and Manda, Lemos and Lemos, Francisco and Marques, Maria M.} }