Premium
The modeling of molecular motions in crystalline polymers
Author(s) -
Boyd Richard H.
Publication year - 1976
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760160516
Subject(s) - polymer , molecular dynamics , work (physics) , chain (unit) , materials science , energetics , molecular mechanics , chemical physics , statistical physics , dielectric , computational chemistry , thermodynamics , physics , chemistry , quantum mechanics , optoelectronics , composite material
Regions in which the mechanical and dielectric properties of polymers change rapidly with temperature (transitions or relaxations) are supposed to be due to the onset of certain types of molecular motions. A precise description of these various molecular motions would be invaluable in the areas, of structure vs property relationships and the tailoring of polymers to end‐uses. However, our knowledge concerning these motions is quite limited and qualitative at best. The biggest stumbling block has been an inability to test the consequences of proposed mechanisms in terms of experimentally observed quantities. The problem in many cases has not been a lack of adequate theory but rather an insufficiency of knowledge, appropriate for input into the theory, concerning the energetics of chain motions. However, in the past few years there has been considerable progress in studying chain energetics by means of conformational energy calculations (molecular mechanics). In the present paper, this work on crystalline polymers will be reviewed and some recent calculations which illustrate the present state of the art are discussed.