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Approaches to conjugated polymers via solid state polymerization
Author(s) -
Sandman Daniel J.,
Kim IkBum,
Njus Jeffrey M.,
Lee DongChan,
Cholli Ashok L.,
Sahoo Sangrama
Publication year - 2003
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.200390043
Subject(s) - polydiacetylenes , diacetylene , thermochromism , polymerization , polyacetylene , materials science , polymer , photochemistry , polymer chemistry , phase transition , conjugated system , chemical engineering , polybutadiene , organic chemistry , chemistry , copolymer , thermodynamics , physics , engineering , composite material
Topochemical solid state polymerization is a method of obtaining fully crystalline macromolecules. Herein, approaches to conjugated polymers via new solid state polymerizations and the properties of materials, especially polydiacetylenes(PDA), obtained via solid state polymerization are discussed. Our attempts to polymerize cyanoalkynes and to define the thermal reaction product of a dicyanodiazepine are presented. Certain PDA exhibit absorption, likely charge‐transfer, at energies below the exciton. Nanocrystals of PDA‐DCH react with liquid bromine to give the mixed polyacetylene PDA‐DCHBr 6 whose visible spectrum exhibits structure not observed in spectra of bulk crystals of PDA‐DCHBr 6 . The thermochromic PDA of the dialkylurethanes of 5,7‐dodecadiyn‐1,12‐diol were studied by variable temperature solid state 13 C nmr. The upfield shift of the acetylene carbons as the temperature is raised above that of the thermochromic phase transition indicates the role of mechanical strains in achieving thermochromism.