ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
Elastic neutron-scattering data from all-hydrogen and selectively deuterated poly(p-phenylene vinylene) (PPV) samples from 296≤T≤616 K are reported. These data, in combination with structure factor refinements, support a nonplanar structural model of the phenylene rings. Increased temperature is accompanied by a gradual rise in both the degree of nonplanarity and in the associated displacements from this mean position. There is also measurable anisotropy in the equatorial thermal expansion coefficients combined with a small 2° drop in the polymer chain setting angle, thereby indicating only a weak approach toward a high-temperature rotator phase. This is in contrast to the pronounced variations seen in polyacetylene and polyethylene, which lack local ring torsional degrees of freedom.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.464616
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