Structure and properties of p-phenylenevinylene-p-xylylene copolymers prepared by vapor-deposition polymerization

Autor: V. G. Klimenko, S. A. Zav’yalov, Sergey N. Chvalun, P. V. Morozov, E. I. Grigor’ev
Rok vydání: 2012
Předmět:
Zdroj: Polymer Science Series A. 54:330-342
ISSN: 1555-6107
0965-545X
DOI: 10.1134/s0965545x12050070
Popis: Films based on the p-phenylenevinylene-p-xylylene precursor are prepared via vapor-deposition polymerization during the pyrolysis of α, α′-dichloro-p-xylene on a copper grid in vacuum at substrate temperatures −196, 25, and 50°C. Subsequent annealing of the precursor at 250°C yields the final material: the copolymer of p-phenylenevinylene and p-xylylene. The structure, surface morphology, and optical properties of the copolymer are studied at different substrate temperatures and copper amounts in the pyrolysis zone. It is found that p-phenylenevinylene units mostly occur in trans configurations. The thermal treatment of the precursor is accompanied by an increase in the mean-square surface roughness and a decrease in roughness coefficient α from 0.84 ± 0.05 to 0.79 ± 0.05. As the content of copper in the pyrolysis zone increases, the concentration of p-xylylene fragments in the copolymer tends to increase; the band gap increases from −2.5 to 3.1 eV. Depending on synthesis conditions, the copolymer is characterized by a shift of the fluorescence spectrum maximum that achieves 150 nm in the visible spectral region.
Databáze: OpenAIRE
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