Abstract
Early in the development of polymer science, Prof. H. Mark suggested that the tensile modulus of polymers should correlate with both the chemical and physical structures of the macromolecule. It was further recognized that maximum property levels would be achieved when all of the molecular chain backbone bonds of the polymer were lined up in the direction of measurement. Such an extended chain morphology has been demonstrated with gel spun polyethylene and with nematogenic polyamides and polyesters. Only main-chain liquid crystalline polymers (LCPs) exhibiting nematic behavior in the fluid state have found fiber applications. All of the LCPs are composed of stiff, highly aromatic monomers and are characterized by domains of high local orientation in the solid state (orientation function >0.95). If processed into fibers, the locally oriented domains are transformed into a single domain of high global molecular orientation parallel to the fiber direction. The thermal analysis literature, associated with lyotropic and thermotropic LCP fibers, is not extensive and work through the first decade of the 21st century and is well summarized in the books edited by Turi and by Menczel and Prime. In this chapter, the materials science of LCP fibers is reviewed, the recent application of TA techniques to LCP fibers is summarized, and the utility and impact of thermal analysis techniques in the understanding of LCP process–structure–property relations are discussed in detail.
Original language | English (US) |
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Title of host publication | Thermal Analysis of Textiles and Fibers |
Publisher | Elsevier |
Pages | 325-334 |
Number of pages | 10 |
ISBN (Electronic) | 9780081005729 |
ISBN (Print) | 9780081005811 |
DOIs | |
State | Published - Jan 1 2020 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- General Engineering
- General Materials Science
Keywords
- Polymer
- domain
- fiber application
- lag-shear model
- process-structure-property relationships
- tensile modulus
- thermal analysis