No abstract

Ceramic fibers are essential components of new high‐temperature‐resistant lightweight materials. The production routes of ceramic filament fibers are complex and in most cases polymeric components or structures are key factors for fiber spinning. Either organic polymers are used as additives in the spinning dopes for oxide ceramic fibers or inorganic polymers are the precursors for the production of non‐oxide fibers. This paper gives an up‐to‐date overview about different ceramic fibers and the chemistry behind the fiber development and production.

Intrinsically conducting polymer fibers are prepared from P3HT by melt spinning. High crystallinity is achieved by drawing the fibers after the spinning process, applying a draw ratio of 1:2. DSC and XRD measurements confirm the continuous increase of crystalline phases with drawing. For comparison, poly(ethylene terephthalate) fibers are coated with P3HT and drawn as well. Again, the drawing of the coated fiber results in a significant increase in crystallinity of the P3HT coating. The high amount of crystalline phases is associated with a dramatic increase in conductivity (350 S · cm−1) after doping with FeCl3 in nitromethane.magnified image

The construction of electrochromic multilayers on textiles is described. Polyester foils are sputtered with a thin layer of translucent indium tin oxide (ITO). On these ITO layers, WO3 and polyaniline (PANI), respectively, are deposited electrochemically in a continuous process. Both the PANI‐ and WO3‐based materials are equipped with an ion‐conductive interface layer composed of lithium poly(styrene sulfonate). Electrochromic elements are made by laminating a PANI‐ and a WO3‐modified substrates together and by fixing the final material on textile substrates. Electrical control is realized by connecting a metallic fabric to each of the two electrochromic parts of the element. The electrochromic behavior of these materials can be switched reversibly within a few minutes.

Poly(4,4‐bis[(3,5‐diethoxybenzoyloxy)methyl]‐1,6‐heptadiyne) is synthesized via cyclopolymerization using modified Grubbs‐ and Schrock‐type initiators. Doping with either I2 or NO+ BF4− yields a conductive polymer with conductivity up to 1.4 × 10−2 S cm−1. The undoped amorphous conjugated polymer is spun into monofilament and multifilament fibers by a wet‐spinning process. Fibers are collected on bobbins with a draw down ratio of 12 resulting in fiber diameters under 60 μm, characterized by scanning electron microscopy. X‐ray diffraction data confirms that the amorphous structure of the polymer is preserved; no additional orientation of the polymer chains occurs during fiber spinning.magnified image