ISSN:
0887-6266
Keywords:
rigid rod polymer
;
thermotropic
;
aromatic polyester
;
oriented film
;
thermal expansion
;
crystal structure
;
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The linear thermal expansion coefficients of oriented films of poly(p-phenylene-2,5-didodecyloxy-terephthalate) in the three structures B, A, and Lf are reported. The results are interpreted in terms of a molecular laminate model in which the rigid main-chain layers are separated by the aliphatic side chains. In a film oriented unidirectionally the rigid mainchain layers provide a negative contribution to the thermal expansion coefficient, while the side chains supply a positive contribution. Therefore, the resulting expansion coefficient α depends on the details of the main- and side-chain packing and low-temperature values between α = +0.3 × 10-5 K-1 (A and Lf and α = -1.2 × 10-5 K-1 (B) are found in highly oriented films. Measurements on undrawn films are in accordance with the molecular laminate model. © 1994 John Wiley & Sons, Inc.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/polb.1994.090320508
