Polyfethylene terephthalate structure

Copolymers, Block Polymers, and Graft Polymers. When more than one monomer is involved, monomer-based names are more complex. Some common polymers have been given names based on an apparent structure, as with polyfethylene terephthalate) A better system has been approved by the lUPAC. With this method, the arrangement of the monomeric units is introduced through use of an italicized connective placed between the names of the monomers. For monomer names represented by A, B, and C, the various types of arrangements are shown in Table 1. 

In addition, the surface should be free of contaminating particles and occlusions that would interfere with the information retrieval process. A typical ablative-mode optical disk has the structure shown in Figme 16.14. The substrate is an optically transparent material such as polycarbonate, PMMA, polyfethylene terephthalate), or polyfvinyl chloride) topped by a subbing layer to provide an optically smooth surface for the recording layer. A metal reflector (typically aluminum) is then incorporated next to a transparent dielectric medium such as poly(a-methyl styrene) and, finally, the absorbing layer where the information pits are created is added. The latter can be a metal-polymer composite (silver particles in a gel) or a dye molecule dispersed in a polymer matrix such as squaryllium dyes, which act as infrared absorbers for GaAs lasers, typically... 

Fig. 10 Molecular formulas and semicrystaUine structure differences of polyfethylene terephthalate), PTT, and polyfbutylene terephthalate)...

Details of the structure of fibers grown from the melt have been derived from an X-ray fiber analysis for the example of polyfethylene terephthalate) [23-25]. The basic X-ray scattering technique is summarized in Appendix 16. The fuU-pattem fiber analysis used in this analysis, the Rietveld method, is given in [26]. The triclinic crystal structure of polyfethylene terephthalate) is illustrated in Fig. 5.68. The unit cell... 

In addition to the nucleating agents discussed in Section 18.4, many other materials have been found to be effective. Whilst the nylons may be self-nucleating, particularly if there is some unmelted crystal structure, seeding with higher melting point polymers can be effective. Thus nylon 66 and polyfethylene terephthalate) are reported to be especially attractive for nylon 6. 

Figure 2.4 Crystal structure of polyfethylene terephthalate). Carbon atoms are shown in gray, oxygen atoms in dark and hydrogen atoms in white colors.

Polyfethylene terephthalate) is a colourless rigid substance. Because of its structural regularity, the polymer readily crystallizes and the physical pro-... 

Fakirov, S. and T. Gogeva, Poly(Ether/Ester)s based on polyftetramethylene terephthalate) and polyfethylene glycol), 3. Effect of thermal treatment and drawing on the structure of the poly(ether/ester)s. Die Makromolekulare Chemie, 191(10) p. 2341.1990. 

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