ISSN:
0021-8995
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
The polymer-polymer solution of poly(vinyl chloride) and poly-ε-caprolactone yields an excellent system for studying the crystallization kinetics of a crystallizable component from a polymer-polymer solution. Unlike previous studies of isotactic-atactic polystyrene solutions for which the glass transition temperature is invariant with composition, this system exhibits a marked dependence of Tg on the composition. The experimental data dE⅓(modulus)/dt (psi⅓/min) were obtained over a composition range of 40 to 70 wt-% poly-ε-caprolactone. With the appropriate modification of the spherulitic growth rate equation, the expression \documentclass{article}\pagestyle{empty}\begin{document}$ \frac{dE^{{1 \mathord{\left/{\vphantom {1 3}} \right.\kern-\nulldelimiterspace} 3}}}{dt}=k'\left( {1 - C_d } \right)_e \frac{-\Delta F_{WLF}}{RT},\left( \Delta F_{WLF}=\frac{4120T}{51.6+T-T_g}\right)$\end{document} approximated a reasonable fit of the experimental data. This demonstrates a marked dependence of the crystallization rate on concentration. Secondary observations of this investigation show a slower crystallization rate for high molecular weight poly-ε-caprolactone and a slow secondary crystallization step. Both homopolymer poly-ε-caprolactone and poly-ε-caprolactone in the poly-ε-caprolactone/poly(vinyl chloride) solution show a slow (relative to the nucleation-controlled step) crystallization stage considered to involve a slow diffusion mechanism.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/app.1973.070171205
