Processing/structure/properties polymer fibers

The development of high performance polymers, such as high modulus fibers and supertough polymer blends, has accelerated in recent years as a direct result of increased knowledge of process-structure-property relationships. Highly oriented... 

FigyibV 1-12 Processing/structure/properties/performance topic timelines for (a) steels, (b) glass-ceramics, (c) polymer fibers, and (d) silicon semiconductors. 

Figure 15.27 Schematic diagram that summarizes the elements of processing, structure, properties, and performance for polymer fibers, which includes components of materials engineering.

Processing/Structure/Properties/Performance correlations and summary concept maps for four materials (steels, glass-ceramics, polymer fibers, and silicon semiconductors), which integrate important concepts from chapter to chapter... 

In the course of his studies of the dyeing process, he became deeply interested in the structure of natural fibers, and most of his efforts were directed toward this new field of research, with the help of able associates, among them R. Brill, M. Dunkel, G. von Susich, and E. Valkd. His investigation of various aspects of the problem utilized physical means (for example, x-ray diffraction, optical properties, and viscosity) and the purely chemical approach. A young scientist, H. Mark, who later became an authority in the field of high polymers, was appointed head of the physical chemistry laboratory. 

Chapter 14 provides the basic principles of polymer science, and addresses the importance of this subject. This chapter aims to give a broad and imified description of the subject matter—describing the polymerization reactions, structures, properties, and applications of commercially important polymers, including those used as plastics, fibers, and elastomers. This chapter focuses on synthetic polymers because of the great commercial importance of these materials. The chemical reactions by which polymer molecules are synthesized are addressed along with the process conditions that can be used to carry them out. This chapter also discusses topics on degradation, stability, and environmental issues associated with the use of polymers. 

The processing of ordered polymer (PBO and PBZT) films is based on pioneering work in polymer synthesis and fiber spinning by the U.S. Air Force and their contractors (3-5). Impressive success has been realized in rigid-rod polymer synthesis (6-7) and fiber spinning from anisotropic solutions (8-9). Structure-property relationships... 

Orientational order plays an important role in solid polymers. It is often induced by industrial processing, for example in fibers and injection- or compression-modulated parts. In polymers with liquid-crystalline properties of the melt or solution, the anisotropies generated by the flow pattern are particularly pronounced. In order to improve the mechanical properties of polymer fibers or films, the degree of orientation is intentionally enhanced by drawing. At the same time, anisotropy of mechanical properties can result in low tolerance to unfavourably directed loads. In many liquid-crystalline polymers, in the mesophase near the transition to the isotropic phase, electric or magnetic fields can induce macroscopic orientational order [1]. Natural polymers such as silk protein fibers, which are biosynthesized and spun under biological condition, also have good mechanical properties because of their ordered structure [2]. 

In Figure 11, the calculated stress at the freeze point is plotted versus the measured birefringence of as-spun fibers for several IV levels of PET. The three lines represent various other workers measurements of the stress-optical coefficient by various techniques, and are all in excellent agreement with the model calculations. This plot demonstrates the bridge between process conditions and polymer properties and developed structure as measured by birefringence. It is Interesting to note that this curve is essentially linear over the entire range of experimental conditions in spite of the fact that... 

Biagiotti, J., Puglia, D., and Kenny Jose, M. A Review on Natural Fibre-Based composites-Part I Structure, Processing and Properties of vegetable Fibres, J. Nat. Fibers, 1(2), 37-68, 2004 Italicized data from McGovern, J.N. Fibers, vegetable. In Polymers— Fibers and Textiles. A compendium. University of Wisconsin, Madison, WI, 1990. 

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