Oriented Crystallization of Random Copolymers
Abstract
A new model for oriented crystallization of copolymers has been developed. It is based on a combination of (1) the Sanchez-Eby formulation for the free energy of melting of a crystal with an arbitrary level of inclusion of comonomeric defects and (2) the entropy of a polymer melt under an anisotropic stress field obtained through Ziabicki and Jarecki’s analysis. The melting temperature, nucleation rate and critical nucleus size have been calculated for model random copolyester systems. The predictions from the model have been shown to correspond to certain striking features of copolymer crystallization for example, rapid crystallization under stress of an otherwise "non-crystallizable" (under quiescent conditions) random copolymer. As a refinement of this model, specific primary structural features of the polymer are taken into account through the use of an RIS-based statistical-segment approach, which enables calculation of the free energy of deformation. Results from experimental studies of crystallization of a series of random copolyesters are discussed in the context of the above model.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 2000
- Bibcode:
- 2000APS..MARM19001S