ISSN:
0025-116X
Schlagwort(e):
Chemistry
;
Polymer and Materials Science
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
,
Physik
Notizen:
Poly(2,5,8,11,14,17,20,23-octaoxapentacosyl methacrylate)-block-poly(4-vinylpyridine) semicomb polymers were synthesized using anionic living polymerization techniques. The polymers are white, powdery materials and were characterized by 1H and 13C nuclear magnetic resonance spectroscopy and gel-permeation chromatography. The polymers display monomodal molecular weight distributions which are relatively narrow. The block copolymers show microphase separation as indicated by the presence of two glass transition temperatures (Tg), a soft (oxyethylene) phase Tg is observed between -60°C and -45°C and a hard (4-vinylpyridine) phase Tg is observed between 135°C and 150°C. The soft oxyethylene phase has been doped with LiClO4 to obtain ionic conductors with electrical conductivities around 5 · 10-6 S · cm-1 at 25°C and the hard 4-vinylpyridine phase has been complexed with 7,7,8,8-tetracyano-1,4-quinodimethane (TCNQ, 2,5-cyclohexadiene-1,4-diylidenedimalonitrile) to obtain electronic conductivities around 10-6 S · cm-1 at 25°C. The mixed (electronic and ionic) conductivities are intermediate between the ionic and electronic conductivities. Higher electronic conductivities (≈ 10-5 S · cm-1 at 30°C) are obtained for the polycation TCNQ-/TCNQ0 complexes.
Zusätzliches Material:
3 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/macp.1991.021921219
Permalink