Explosive polymerization

Tetrafluoroethylene undergoes addition reactions typical of an olefin. It bums in air to form carbon tetrafluoride, carbonyl fluoride, and carbon dioxide (24). Under controlled conditions, oxygenation produces an epoxide (25) or an explosive polymeric peroxide (24). Trifluorovinyl ethers,... 

Chemical Reactivity - Reactivity with Water Mild reaction, non-hazardous Reactivity with Common Materials Contact with silver or aluminum may cause polymerization Stability During Transport Stable unless heated under pressure Neutralizing Agents for Acids and Caustics Flush with water Polymerization Explosive polymerization can occur when in contact with acids Inhibitor of Polymerization None used. 

Chemical Reactivity - Reactivity with Water No reaction Reactivity with Common Materials No reaction Stability During Transport Stable Neutralizing Agents for Acids and Caustics Not pertinent Polymerization Heat may cause an explosive polymerization. Strong ultraviolet light can also initiate polymerization Inhibitor of Polymerization Hydroquinone and its methyl ether, in presence of air. ... 

Traces of oxygen in nitrogen used for inerting can react with some products, such as butadiene and acrolein, and cause explosive polymerization. In one case, unknown to the acrolein plant, a trace of oxygen was deliberately added to the nitrogen supply at the request of another plant. 

The effect of monomer concentration was studied using n-pentane solvent and maintaining the total volume of isobutylene plus n-pentane constant. Methyl halide concentration was kept constant so as to maintain constant medium polarity. Attempts were made to keep conversions below 20%. At -30 °C, due to almost explosive polymerizations, conversions could only be maintained below 40%. 

These monomers polymerize readily in presence of light, heat or catalysts (such as benzoyl peroxide) and must always be stored or shipped with inhibitor present to avoid spontaneous and explosive polymerization. 

Addition of 98—100% formic acid may explosively polymerize the alcohol (Ref 5a). 

Halogenated compounds such as carbon tetrachloride and chloroform have particularly high chain-transfer constants. However, these compounds must be used with extreme caution as explosive polymerizations have been observed. 

Alkoxyalkyl Hydroperoxides. These compounds (1, X — OR R — H) have been prepared by the ozonization of certain unsaturated compounds in alcohol solvents. Alkoxyalkyl hydroperoxides are more commonly called ether hydroperoxides. They form readily by the autoxidation of most ethers containing cr-hydrogens, e.g., dioxane. tetrahydrofuran, diethyl ether, diisopropyl ether, di-n-butyl ether, and diisoamyl ether. From certain ethers, e.g., diethyl ether, the initially formed ether hydroperoxide can yield alcohol on standing, or with acid treatment form dangerously shock-sensitive and explosive polymeric peroxides. 

This group covers polymeric peroxides of indeterminate structure rather than polyfunctional macromolecules of known structure. These usually arise from autoxidation of susceptible monomers and are of very limited stability or explosive. Polymeric peroxide species described as hazardous include those derived from butadiene (highly explosive) isoprene, dimethylbutadiene (both strongly explosive) 1,5-p-menthadiene, 1,3-cyclohexadiene (both explode at 110°C) methyl methacrylate, vinyl acetate, styrene (all explode above 40°C) diethyl ether (extremely explosive even below 100°C ) and 1,1-diphenylethylene, cyclo-pentadiene (both explode on heating). 

Caution HCN is a highly toxic, volatile liquid (bp 27 °C) that is also susceptible to explosive polymerization in the presence of base catalysts. It should be handled only in a well-ventilated fume hood and by teams of at least two technically qualified persons who have received appropriate medical training for treating HCN poisoning. Sensible precautions include having available proper first aid equipment and HCN monitors. Uninhibited HCN should be stored at a temperature below its melting point (-13 °C). Excess HCN maybe disposed by addition to aqueous sodium hypochlorite, which converts the cyanide to cyanate. 

The polymerization of tubulin has many similarities to that of actin. The protomer is the tubulin heterodimer. Each subunit in the heterodimer can bind a nucleotide in this case it is GTP. There is a lag period associated with nucleation. Once sufficient nuclei are available, explosive polymerization can proceed from both ends of the nuclei. Calcium ions and low temperature (4°C) inhibit polymerization, while magnesium ions and high temperature (37°C) stimulate it. As with actin, the microtubule is polar, and polymerization proceeds about three times more quickly from the plus end than the minus end. Polymerization is accompanied by hydrolysis of GTP, on the /3-tubulin only, at or soon after the addition of the a//3 protomer to the filament. GTP caps can therefore exist at both ends of the filament with the cap likely to be larger, on average, at the plus end than at the minus end. 

Synonyms and trade names cyanoethylene, 2-propenenitrile, vinyl cyanide Use and exposure Acrylonitrile is a colorless, man-made liquid with a sharp, onion- or garlic-like odor. It can be dissolved in water and evaporates quickly. Acrylonitrile is used principally as a monomer in the manufacture of synthetic polymers, polyacrylonitriles, acrylic fibers, and other chemicals such as plastics and synthetic rubber. A mixture of acrylonitrile and carbon tetrachloride was used as a pesticide in the past. - Acrylonitrile is highly flammable and toxic. It undergoes explosive polymerization. The... 

No mononuclear alkyne complexes containing PF3 have been reported to date but a number of complexes of the type [Rh2(PF3)6(alkyne)] listed in Table IX have been obtained by heating a solution of [Rh2(PF3)8] in n-hexane under reflux in an inert atmosphere with an equimolar amount of the alkyne (method A). Care must be taken in the case of MeC02C=CC02Me and HC=CC02Me since reactions occur below room temperature to give the red complexes [Rh2(PF3)5(alkyne)2] (see Section IX), while explosive polymerization of the alkyne occurs above room temperature. The [Rh2(PF3)5(alkyne)2] compounds have been assigned a metallocyclo-pentadiene structure. 

Serum and bile thiocyanates are raised. See also HYDROCYANIC ACID. Unstable and easily oxidized. Explosive polymerization may occur on storage with silver nitrate. Potentially explosive reactions with benzyltrimethylammonium hydroxide + pyrrole, tetrahydrocarbazole + benzyltrimethylammonium hydroxide. Violent reactions with strong acids (e.g., nitric or sulfuric), strong bases, azoisobutyronitrile, dibenzoyl peroxide, di-tert-butylperoxide, or bromine. 

O2) or (CIF3 + water). Potentially explosive polymerization reaction with ethylene. Incompatible with 1,1-dichloroethylene oxygen. When heated to decomposition it emits toxic fumes of F and CL. See also CHLORINATED HYDROCARBONS, ALIPHATIC and FLUORIDES. 

SAFETY PROFILE Poison by ingestion, inhalation, and intraperitoneal routes. Moderately toxic by skin contact. Experimental reproductive effects. Combustible when exposed to heat or flame. To fight fire, use CO2, dry chemical. Thermally unstable. Contact with moisture (water), acids, or alkalies may cause a violent reaction above 40°. Concentrated aqueous solutions may undergo explosive polymerization. Mixture with 1,2-phenylenediamine salts may cause explosive polymerization. When heated to decomposition or on contact with acid or acid fumes, it emits toxic fumes of CN and NOx. See also CYANIDE and AMIDES. 

Flammable Liquid SAFETY PROFILE Mildly toxic by ingestion. Mutation data reported. A skin irritant. A very dangerous fire and explosion haxard when exposed to heat or flame can react vigorously with oxidizing materials. To fight fire, use alcohol foam, foam, CO2, dry chemical. Explosive polymerization is catalyzed by methane sulfonic acid. When heated to decomposition it emits acrid smoke and irritating fumes. See also ETHERS. 

OSHA PEL TWA 1 mg(Fe)/m3 ACGIH TLV TWA 1 mg(Fe)/m3 DOT CLASSIFICATION 8 Label Corrosive SAFETY PROFILE Poison by ingestion and intravenous routes. Experimental reproductive effects. Corrosive. Probably an eye, skin, and mucous membrane irritant. Mutation data reported. Reacts with water to produce toxic and corrosive fumes. Catalyzes potentially explosive polymerization of ethylene oxide, chlorine + monomers (e.g., styrene). Forms shock-sensitive explosive mixtures with some metals (e.g., potassium, sodium). Violent reaction with allyl chloride. When heated to decomposition it emits highly toxic fumes of HCl. 

SAFETY PROFILE A poison by subcutaneous route. Questionable carcinogen with experimental tumorigenic data. Catalyzes the potentially explosive polymerization of ethylene oxide. Explosive reaction when heated with guanidinium perchlorate. Reaction with carbon monoxide may form an explosive product. Potentially violent reaction with hydrogen peroxide. 

Iodine pentafluoride depletes the limonene inhibitor and then causes explosive polymerization of the monomer. Mixtures with hexafluoropropene and air form an explosive peroxide. Reacts violendy with SO3 air difluoromethylene dihypofluorite dioxygen difluoride iodine pentafluoride oxygen. When heated to decomposition it emits highly toxic fumes of F". See also FLUORIDES. 

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