Spinning fume

Materials that are corrosion resistant to the expected cathodic polarization qualify as impressed current cathodes. Austenitic CrNi steels are used with strong acids. The oleum (i.e., fuming sulfuric acid) and concentrated sulfuric acid tanks used in sulfonating alkanes and in the neutralization of sulfonic acids are anodi-cally protected using platinized brass as cathodes [15]. Lead cathodes are used to protect titanium heat exchangers in rayon spinning baths [16]. 

Nucleating agents, such as fumed silica and kaolin, are usually added to the spin mix to facilitate spin agent flashing and to obtain uniform small size cells (12). 

All-p-phenylene oxadiazole/N-methyl hydrazide copolymers have yielded high performance fibers with tenacities of 18-21 gpd and moduli above 300 gpd through an unconventional polycondensation reaction of terephthalic acid, dimethyl terephthalate and hydrazine sulfate in fuming sulfuric acid and subsequent "reaction spinning" into aqueous acid. 

Fibers (6) of p-phenylene oxadiazole/N-methyl hydrazide copolymers were prepared by polymerization of terephthalic acid (TA), dimethyl terephthalate (DMT) and hydrazine sulfate in fuming sulfuric acid (Oleum) and "reaction spinning" of the resulting polymer solution into aqueous sulfuric acid. Replacement of some of the dimethyl terephthalate used with dimethyl isophthalate (DMI) allowed the preparation of p-/m-phenylene oxadiazole/ N-methyl hydrazide copolymers. In the polymerization, a p-/m-phenylene oxadiazole polymer is formed which is methylated during the reaction ... 

During the polymerization of aromatic diacids and diesters with hydrazine in fuming sulfuric acid, aromatic oxadiazole units are formed first which are subsequently methylated by monomethyl sulfate or its homologues (derived from reaction of the diester with H2SO4) forming an aromatic N-methyl oxadiazolium polymer. This polymer is hydrolyzed during the spinning operation to the fiber polymer, i.e., p-/m-phenylene oxadiazole/N-methyl hydrazide copolymer. 

Hazardous Decomp. Prods. On decomp., emits toxic fumes of NO, NEPA Health 1, Flammability 2, Reactivity 0 Storage Store In cool, dry, well-ventilated area, out of direct sunlight Uses Solvent for llqs., gases. In vinyl resins, acetylene, butadiene, acid gases, paints, paint strippers, cleaners, zinc electroplating, acrylic fiber spinning, pharmaceuticals mfg. of polyacrylic fibers, butadiene. 

Toxicology LD50 (oral, rat) 4150 mg/kg, (IV, rat) 390 mg/kg poison by IV route mod. toxic by ing. irritating to skin and eyes TSCA listed Hazardous Decomp. Prods. Heated to decomp., emits acrid smoke and irritating fumes Uses Surfactant, thickener, emulsifier, vise, control agent, lubricant, solubilizer for personal care prods. emulsion polymerization surfactant textile spin finishes emulsifier for antibiotic gels... 

Properties Liq. fumes in air m.w. 99.18 dens. 0.867 (0 C) b.p. 132-134 C flash pt. 48.2 F Precaution Very dangerous fire hazard Hazardous Decomp. Prods. Heated to decomp., emits toxic fumes of NOx Uses Intermediate for pharmaceuticals catalyst surface treatment agent for copper in printed circuit boards stabilizer for polyvinyl alcohol spinning sol ns. template for molecular sieves... 

---