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Random fluorinated copolymers of tetrafluoroethylene: a study of the inclusion/exclusion of defects from the crystal by conformational and packing energy calculations
Author(s) -
Napolitano Roberto,
Pucciariello Rachele
Publication year - 1996
Publication title -
macromolecular theory and simulations
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.37
H-Index - 56
eISSN - 1521-3919
pISSN - 1022-1344
DOI - 10.1002/mats.1996.040050601
Subject(s) - tetrafluoroethylene , chlorotrifluoroethylene , polytetrafluoroethylene , copolymer , crystal (programming language) , materials science , crystal structure , crystallography , vinyl ether , lattice energy , polymer chemistry , phase (matter) , ether , chemistry , organic chemistry , composite material , polymer , computer science , programming language
A conformational analysis has been performed on the isolated chains of copolymers of tetrafluoroethylene with hexafluoropropene, chlorotrifluoroethylene or perfluoromethyl vinyl ether, in comparison with polytetrafluoroethylene. The lowest energy conformations in accordance with the chain repeating distance of polytetrafluoroethylene in the low temperature crystal phase have been used in packing energy calculations. The results of both conformational and packing energy calculations suggest that the Cl group is easily tolerated in the crystal phase. The —CF 3 group could also be tolerated in the crystal phase but at the cost of conformational and crystal lattice deformations. On the contrary, it can be concluded that the —OCF 3 group is excluded from the crystal phase because its presence should require high energy values and wide deformations in the unit cell parameters.