Poly aramid-6-polyester elastomers

This section summerizes syntheses and properties of aramid elastomers with 

A novel synthetic route to aramid-b-polyester elastomers 

One of the possible applications of the thermoplastic aramid elastomers is in the production of melt spinnable elastic fibers [41,48,86]. Strong elastic fibers 

Elastomer Shore A hardness (point) Shore D hardness (point) Tensile strength (MPa) Elongation at break (%) Permanent set (%) 

Therefore, these materials are attracting research interest, especially in designing novel elastomers with unique combinations of aramid and soft segments, and in improving the synthetic routes and the structure analyses. So far, the phase and crystal structures of these materials have not been fully described and understood. Consequently, the understanding of the microstructures would be a key of great importance to enhance the unique properties of thermoplastic aramid elastomers. 

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Textile fibers (cotton, silk, wool, hair, rayon, nylon, polyester, aramid, etc.) Structural materials (lumber, composites, poly(oxymethylene), PVC, nylon, etc.) Rastios (polyethylene, polypropylene, polytetrafluoroethylene, polyoxide, etc.) Adhesives (glues, epoxies, polyvinyl alcohol, synthetic rubber, segmented polyurethanes, etc.) Biological materials (the basic molecules, carbohydrates, proteins, and DNA)... 

Flexible linear macromolecules make up, as mentioned before, the newest class of molecules and are the molecules most important to man. Their number is practically unlimited. For examples, almost all textile fibers are flexible macromolecules, from cotton, silk, wool, hair, and rayon to nylon, polyesters, and aramid. Many structural materials are also flexible macromolecules, such as lumber, compmsites, polyoxyethylene, poly(vinyl chloride), and nylon. Because of the ease of melting, many flexible macromolecules have earned the name plastics, such as polyethylene, polypropylene, polytetra-fluoroethylene, and polyoxides. Many adhesives such as glues, epoxides, poly-(vinyl alcohol), cyanoacrylic polyesters, and ethylene-vinyl alcohol copolymers are based on flexible macromolecules. The unique combination of viscosity and elasticity in the liquid state makes many flexible macromolecules useful as elastomers, of which natural and synthetic robbers and segmented polyurethanes are best known. Class 2 also includes the biolo cal macromolecules carbohydrates, proteins, and DNA. The biological macromolecules alone are practically unlimited in number, as documented by the variety of forms of life. 

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