Spin of polyacrylonitrile

R. Moreton and W. Watt, The spinning of polyacrylonitrile fibres In clean room conditions for the production of carbon fibres, Carbon, 12, 543-554 (1974). 

Moreton R, Spinning of polyacrylonitrile precursor fibres with reference to the properties of carbon fibres, 3" Conference, Industrial Carbons and Graphite, SCI, London, 1970. 

Fig. 11-35 Relative solvent concentration vs LIVl for dry spinning of polyacrylonitrile in dimethylformamide each curve at temperature in with an extrusion temperature of llO C L, overall spinning length of 6.45 m air velocity of 2 m/s Vl and Rl are taken-up velocity and radius [52].

Eleikkila, P Harlin A Electro spinning of polyacrylonitrile (PAN) solution effect of conductive additive and filler on the process. Express Polymer Letters 2009, 3, 437-445. 

In the case of solvent spinning, ie, secondary acetate, polyacrylonitrile, and poly(vinyl chloride), the FWA is added to the polymer solution. An exception is gel-whitening of polyacrylonitrile, where the wet tow is treated after spinning in a washbath containing FWA. 

More than 95% of current carbon fiber production for advanced composite appHcations is based on the thermal conversion of polyacrylonitrile (PAN) or pitch precursors to carbon or graphite fibers. Generally, the conversion of PAN or pitch precursor to carbon fiber involves similar process steps fiber formation, ie, spinning, stabilization to thermoset the fiber, carbonization—graphitization, surface treatment, and sizing. Schematic process flow diagrams are shown in Eigure 4. However, specific process details differ. 

Hollow-fiber permeators, 26 22 Hollow fibers, 13 389-390 cellulose ester, 26 19 cellulosic, 26 18-20 ion-exchange, 26 15 mechanical considerations and dimensions for, 26 5-7 natural polymer, 26 23 polyacrylonitrile, 26 23 polyamide, 26 21-22 post-treatment of, 26 13-14 preparation of, 26 3 production of, 19 757 with sorbent walls, 26 26 technology of, 26 27 wet spinning of, 25 816, 817-818 Hollow-fiber spinning processes, 26 7-12 Hollow fiber spinning technology,... 

P.Br.22 presents medium to slightly reddish shades. It is used for the spin dyeing especially of polyacrylonitrile and viscose. 

Dyes with 3-aminopyrazole or its derivatives [107] as diazo component dye polyacrylonitrile yellow, e g. 46. The tetrafluoroborate of this dye is used for spin dyeing polyacrylonitrile [108]. 

Polyacrylonitrile, which is a semicrystalline polymer, can be used for many engineering applications, such as fiber spinning or for housing and package applications. A peculiarity of polyacrylonitrile is that it is insoluble in its monomer. This makes it very difficult to homopolymerize acrylonitrile in an emulsion polymerization process since nucleated polymer particles cannot grow by monomer swelling. 

No such relationship was observed in the case of polyethylene mixtures with butyl rubber (Fig. 6). We came to the conclusion that the activity of polyacrylonitrile as a filler can be connected with EDA interactions between electrons of double bonds and -C E N groups. No such complex type has so far been detected in polymer mixtures. In the given instance an EDA complex could appear only at the interphase boundary and its concentration would be quite low. However, certain symptoms of its existence have been observed. PAN added in the amount of 30 phr raised the cis-1,4-poly-butadiene Tg towards higher temperature region by 4-15 K. This was observed by means of thermomechanical analysis under dynamic as well as under static conditions (Figs. 7 and 8). The presence of the immobilized layer of PB on the PAN domains was also established in studies carried out by the method of pulse NMR. In the mixtures of PB with PAN there appeared additional compliances of the relaxation time T2 "spin-spin" (Fig. 9), as well as relaxation time T "spin-network" (Fig. 10). This indicates that part of the elastomer has... 

The plant will house all the facilities necessary for raw material preparation and storage, batch polymerization processing (conversion of acrylonitrile monomer into polyacrylonitrile), the spinning of the polymerized product into yarn, all further processing and drying necessary to form the PAN precursor, collection of the precursor on bobbins, and the final pyrolization process that forms the carbon fiber product. 

The third is a fiber with an easy fibrillation. The fiber is spun by gelation-spinning of a mixture of PVA and another polymer, such as polyacrylonitrile, which is soluble in dimethyl sulfoxide. Phase-separated fibers are produced the continuous phase consists of PVA, and the noncontinuous phase consists of polyacrylonitrile. The fiber can be fibrillated with physical strengths such as milling in rubber, stirring in water, and jet-streamed water, to result in fibrillated fibers with diameters less than 1 pm (0.01 den). 

Yusof N, Ismail AF (2012) Post spinning and pyrolysis processes of polyacrylonitrile (PAN)-based carbon fiber and activated carbon fiber a review. J Anal Appl Pyrol 93 1-13... 

Grobe V, Mann G, Structure formation of polyacrylonitrile solutions into aqueous spinning baths, Faserforsch Textiltech, 19, 49-55, 1968. 

Tsai JS, Effect of drawing ratio during spinning and oxidation on the properties of polyacrylonitrile precursor and resulting carbon-fiber, J Mater Sci Lett, 11(3), 140-142, 1992. 

The most important methods for the preparation of polyacrylonitrile are solution polymerization and suspension polymerization. The former method is particularly convenient, since when a solvent for the polymer is used, the resulting solution may be utilized directly for fibre spinning. Concentrated aqueous solutions of inorganic salts such as calcium thiocyanate, sodium perchlorate and zinc chloride make suitable solvents suitable organic solvents include dimethylacet amide, dime thy Iformamide and dimethylsulphoxide. Emulsion polymerization suffers from the disadvantage that the monomer has appreciable water-solubility and the formation of polymer in the aqueous phase can lead to coagulation of the latex. This tendency is reduced by the addition of ethylene dichloride to the system. 

Chen JC (1998) Modification of polyacrylonitrile (PAN) precursor fiber via post-spinning plasticization and stretching. PhD Thesis, The Pennsylvania State University, University Park, PA, USA... 

---