Nascent fibers

Figure 3 Surface view of the fiber severed after the run through a guide In the coagulation hath. The apparent damage Is a result of excessive friction of the nascent fiber with the guide, (and Is shown In Figure 2 as two stipes on the fiber surface).

Figure 4 Cross-section of nascent fiber after 1 second coagulation period. (The fiber was severed 15 cm under the spinneret In the coagulation bath).

Nascent fiber in a dry-jet wet-spinning process with a reasonable air-gap distance. (Short-range and random chain structure)... 

Using a 25 wt% EB/NMP/HPMI solution, we also spun a batch of fiber into a 20 wt% NMP aqueous bath. The PANI fibers were processed using coagulation bath temperature of 20°C with a take-up speed on the first godet of 10 m/min. Typically, in the water bath, the nascent fiber formed within a few minutes. In order to remove any residual solvent (NMP and HPMI) from the as-spun fiber, we usually kept the fibers in a water bath for 24 h. However, for the same dope solution, which was spun into the... 

In the preparation of these concentrated PANI-AMPSA/DCAA solutions according to the procedures reported by Monkman and coworkers [59-61], it was noticed that the high-molecular-weight EB powders, which had been dried in the vacuum oven (water content <0.5 wt%), had difficulty wetting upon addition to the DCAA solvent. This problem could be overcome by the addition of a trace amount of water to the EB powder before it was dissolved in the DCAA solvent. However, there was a finite water limit. Above 30 wt% water in EB powder, the nascent fiber flattened and fell apart in the coagulation bath. Furthermore, it was found that fiber with good mechanical properties could only be spun if the water content in the EB powders was between 2 and 10 wt%. Thus, with appropriate mixing conditions, PANI-AMPSA/DCAA dope solutions with a total solids content between 4.5 and 14 wt% may be prepared... 

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