ISSN:
0022-3832
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The rate of spherulite growth has been measured for various polymers. Several authors have developed the theory for the rate with emphasis on its temperature dependence but without reference to its absolute value. In this paper, a theory of the absolute rate of growth is put forward on the basis of the perfect crystal growth mechanism of Volmer-Frenkel and the absolute reaction rate theory of Eyring. The linear rate of growth, G is given by \documentclass{article}\pagestyle{empty}\begin{document}$ G=(4kT/d_1 d_3 \eta L)[1 - \exp \{ - \frac{{H_m T}}{{RT_m ^\circ T}}\}]\exp \{ - 1/18\frac{{H_m T_m ^\circ}}{{RTT}}\} $\end{document} For typical polymers, this equation is approximated by \documentclass{article}\pagestyle{empty}\begin{document}$ G=(4kT/d_1 d_3 \eta L)\exp \{ - 1/18\frac{{H_m T_m ^\circ}}{{RTT}}\} $\end{document} where d1 is the diameter of the polymer molecular, d3 the length of the segment, ηL the local viscosity near the crystal surface, ΔHm the heat of fusion for a mole of segments, Tm° the equilibrium melting temperatures, and ΔT = Tm° - T. The glass temperature for the local viscosity is assumed to be lower by δTg than that for usual viscosity, and the equilibrium melting temperature Tm° is assumed to be 5° higher than the apparent melting point Tm. The values of G calculated by this theory show good agreement with observed values for polyethylene succinate and nylon 6.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1960.1204213924
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