Liquid crystalline main chain polymers with a poly(p-phenylene-terephthalate ) backbone. 7. Thermal expansion of oriented films of the polyester with dodecyloxy side chains
article
The linear thermal expansion coefficients of oriented films of poly(p-phenylene-2,5-di-dodecyloxy-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 main-chain 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 (A and Lf) and α=-1.2×10-5K-1(B) are found in highly oriented films. Measurements on undrawn films are in accordance with the molecular laminate model.
Topics
TNO Identifier
232438
ISSN
08876266
Source
Journal of Polymer Science. Pt.B: polymer physics, 32(5), pp. 851-857.
Collation
7 p.
Pages
851-857
Files
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