ISSN:
0032-3888
Schlagwort(e):
Chemistry
;
Chemical Engineering
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
,
Maschinenbau
,
Physik
Notizen:
The strain-induced crystallization phenomenon of a crosslinked polymer network was studied using statistical, thermodynamics. The basic approach was essentially that used by Flory (1), but in this work Flory's assumption of only a single crystalline phase (the extended-chain crystalline structure with chain parallel to stretch direction) was abandoned. The dimension of the crystalline vector-which is assumed to be parallel to the stretch direction and the percent crystallinity is taken as two independent variables instead of being treated as one single variable. A single variable treatment is inherent in the assumption of a single extended-chain crystallite. By use of the present approach, either the folded-chain crystallite or the extended-chain one is found to be thermodynamically stable depending on temperature, stretch ratio and molecular weight. The retractive force of a crystallized polymer network has been calculated. It is shown theoretically that the formation of an extended-chain crystallite will cause the retractive force to decrease, and that the formation of a folded-chain crystallite will cause the retractive force to increase in a reversible crystallization process.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/pen.760190604
