Polymers spinning

Tetrathiafulvalene (TTE) has also been used in electrochromic devices. TTE-based polymers spin-coated onto transparent electrode surfaces form stable thin films with reproducible electrochromic properties (100). The slow response of these devices has been attributed to the rate of ion movement through the polymer matrix. 

Dry Spinning. On a worldwide basis, about 90% of all spandex fibers are produced by various adaptations of dry spinning (15,16). The solution dry spinning process is illustrated in Figure 5. The polymer spinning solution is metered at a constant temperature by a precision gear pump... 

Fig. 6. Schematic of dry-jet wet spinning employing tube-in-orifice spinneret A, bore injection medium (liquid, gas, or suspended soHds) B, pump C, spinneret D, polymer spinning solution E, micrometer ( -lm) "dope" filter F, coagulation or cooling bath G, quench bath and H, collection spool.

Fig. 20. A hoUow-fiber solution-spinning system. The fiber is spun into a coagulation bath, where the polymer spinning solution precipitates forming the...

Schaefer, J. and Stejskal, E.O. (1975) Carbon-13 nuclear magnetic resonance of polymers spinning at the magic angle. J. Am. Chem. Soc., 98,... 

Fig. 12.1.1 Dependence of order parameter, S. of the secondary polymer, spin-labeled poly (methyl methacrylate) (PMMA) and polystyrene (PST), bound to poly(maleic anhydride—styrene )-grafted silica on hexane content in ethyl acetate-hexane cosolvent. Numbers in parentheses are number average molecular weight of the secondary polymer. (From Ref. 48.)...

Polymer processing 100-400 polymer spinning polymer filtration polymer extrusion... 

Figure 12.13 shows the Xe spectra of a iPP/EP blend obtained with single pulse excitation and with => 129Xe cross-polarisation at -33 °C [13]. In the cross-polarisation spectrum only the Xe line from Xe in iPP is observed, because the dipolar interaction between the polymer spins and the 129Xe spins due to the Xe mobility is too weak in EP. Also the cross-polarisation signal of iPP disappears at temperatures higher than the Tg of iPP. 

Spinning of PCS, often with the use of an organic-polymer spinning aid such as poly (ethylene oxide), followed by curing and high-temperature pyrolysis gives black silicon-carbide-like fibers. 

Currently it is discussed in the literature that for large conjugated polymers spin-statistics might not be applicable however, this discussion is irrelevant for triplet emitters with high ISC rates (compare [67-74]). 

The negative first normal stress difference under a medium shear rate, characterized by liquid crystalline polymers, makes the material avoid the Barus effect—a typical property of conventional polymer melt or concentrated solution, i.e., when a polymer spins out from a hole, or capillary, or slit, their diameter or thickness will be greater than the mold size. The liquid crystalline polymers with the spin expansion effect have an advantage in material processing. This phenomenon is verified by the Ericksen-Leslie theory. On the contrary, the first normal stress difference for the normal polymers is always positive. 

Acetonitrile is used as a solvent for polymers, spinning fibers, casting and molding plastics, and HPLC analyses for extraction of butadiene and other olefins from hydrocarbon streams in dyeing and coating textiles and as a stabilizer for chlorinated solvents. It occurs in coal tar and forms as a by-product when acrylonitrile is made. 

I 9 Technical developments related to photochemical processes in polymers SPIN - COATING... 

An AFM study of the topology of polymer spin-coated depositions of Glu-containing ELPs, from acid and basic solutions, on a Si hydrophobic substrate at temperatures below Tt has shown that in acidic conditions, the polymer deposition just shows a flat surface without particular topological features (Fig. 10a). 

Company Fiber Polymer Spin Method Cure Method Pyrolysis " Ceramic Composition... 

Spin coat NLO polymer Spin coat photoresist... 

Second exposure (A,) Expose photoresist (UV, mask) Wet process photoresist Plasma etch Strip photoresist Spin coat NLO polymer Spin coat top cladding layer... 

R)-21 gives very well resolved H and - C NMR spectra that are consistent with the polymer structure. The methylene chloride solution of R)-ll shows a UV absorption maximum at = 328 nm. This absorption is shifted only slightly in the solid state. Thin films of the polymer spin coated on glass slides show absorption at = 324 nm. Strong emission is observed for the methylene chloride solution of the polymer at Ag j = 388 and 407 nm when excited at 328 nm. The NMR, UV, and fluorescence spectra of rac-22 are almost the same as those of (/ )-22. 

Figure I. Electrospiming set-up (I power source 2 polymer spin-dope solutions 3 collection target 4 ground) (Reproducedfrom reference 11. Copyright 2002 American Chemical Society.)...

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