ISSN:
0449-2951
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
In a previous paper the end-to-end dimensions of semicrystalline macromolecules were computed by the Markoff chain method, by use of a normalized probability matrix with two probability parameters α and p. The values of these parameters that actually obtain may result from kinetic conditions (as in rapidly quenched specimens) or the values may in some cases be equilibrium values that can be determined by statistical mechanical considerations. In this paper we calculate the overall partition function Q of a semicrystalline macromolecule by a method similar to that employed by Zimm and Bragg for polypeptide chains. Q is computed in terms of segment partition functions fr, fh, and fk. By working out the consequences of this Ising-type model, we are able to relate α and p to fr, fh, and fk. In an appendix we show that the phenomenon of ceiling and floor temperatures in equilibrium polymerization can be regarded from the same mathematical point of view as the helix-coil transition. Moreover, the mathematical results from this approach can be correlated with the results previously obtained by Tobolsky and Eisenberg by direct application of the law of mass action.
Additional Material:
2 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1963.100010127