Local Mechanism of Phenyl Ring π-Flips in Glassy Polycarbonate
1997; American Chemical Society; Volume: 30; Issue: 6 Linguagem: Inglês
10.1021/ma9611432
ISSN1520-5835
AutoresDuane R. Whitney, Robert Yaris,
Tópico(s)Protein Structure and Dynamics
ResumoIn order to obtain the mechanism for the infrequent phenyl ring π-flips in glassy polycarbonate, a generalized Langevin dynamics simulation was performed on a reduced model consisting of a flipping ring and its keeper ring. The frequency of π-flips and activation energy for π-flips obtained from the simulation are in agreement with experiment. A phenyl ring π-flip occurs when there is an increase in the separation distance between the ring and its nearest neighbor ring on another chain, accompanied by, and in synchrony with, an increase in its rotational kinetic energy.
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