Polymeric-peroxidic liquid

Caglioti et al.35 subjected C2F4-02 mixtures at about one atm total pressure to X-rays, y-rays, ultraviolet radiation, or heat (100°C for 14 hr). In all cases they found CF20, C2F40, c-C3F6, and a polymeric-peroxidic liquid (C2F402) as products. 

At 100°C and 1 atm pressure, Caglioti et al.35 found that a 2 1 mixture of C2F4 and 02 that stood for 14 hr gave equal amounts of CF20 and c-C3F8 as principal gas-phase products and smaller amounts of C2F40. The polymeric peroxidic liquid (C2F4Oa) was also formed. 

Accidental admixture of oxygen gas with unstabilised liquid tetrafluoroethylene produced a polymeric peroxide which was powerfully explosive, and sensitive to heat, impact or friction [1], Removal of oxygen by treatment with pyrophoric copper to prevent explosion of tetrafluoroethylene has been claimed [2],... 

Reaction between oxygen and butadiene in the liquid phase produces polymeric peroxides that can be explosive and shock-sensitive when concentrated. Ir(I) and Rh(I) complexes have been shown to catalyze this polymerization at 55°C (92). These peroxides, which are formed via 1,2- and 1,4-addition, can be hydrogenated to produce the corresponding 1,2- or 1,4-butanediol [110-63-4] (93). Butadiene can also react with singlet oxygen in a Diels-Alder type reaction to produce a cyclic peroxide that can be hydrogenated to 1,4-butanediol. 

Butadiene reacts readily with oxygen to form polymeric peroxides, which are not very soluble in liquid butadiene and tend to settle at the bottom of the container because of their higher density. The peroxides are shock sensitive therefore it is imperative to exclude any source of oxygen from butadiene. Addition of antioxidants like /-butylcatechol (TBC) or butylated hydroxy toluene (BHT) removes free radicals that can cause rapid exothermic polymerizations. Butadiene shipments now routinely contain about 100 ppm TBC. Before use, the inhibitor can easily be removed (247,248). Inert gas, such as nitrogen, can also be used to blanket contained butadiene (249). 

The polymeric peroxides, ( OOCH-CXH ) , where X = H, GTL, (T1 (T l> etc., are viscous liquids or amorphous solids having as many as 10 repeating units. These compounds usually explode when heated. The products obtained from the thermal or photodecomposition show that cleavage of both oxygen-oxygen and carbon-carbon bonds occurs. 

Polymeric a-Oxygen-Suhstituted Peroxides. Polymeric peroxides (3) are formed from the following reactions ketone and aldehydes with hydrogen peroxide, ozonization of unsaturated compounds, and dehydration of ur-hydroxyalkyl hydroperoxides consequently, a variety of polymeric peroxides of this type exist. Polymeric peroxides are generally viscous liquids or amorphous solids, are difficult to characterize, and are prone to explosive decomposition. 

The very first reported PHOST that is transparent in the DUV was prepared by thermolysis or acidolysis of PBOCST, which is in turn prepared via radical polymerization of the BOCST monomer by 2,2-azobis(butyronitrile) (AIBN), benzoyl peroxide (BPO), or other radical initiators. The BOCST monomer can be prepared by the Wittig reaction on a protected 4-hydroxybenzaldehyde with a rather high yield due to the good stability of the t-BOC group toward a base cata-lyst. " The PBOCST polymer thus obtained is readily converted to PHOST by heating the polymer to 200°C or by treating the polymer with an acid such as acetic acid or HCl in solution. And PBOCST can be synthesized via cationic polymerization in liquid sulfur dioxide. ... 

Applies to ethers etc. Peroxides can form in the storage area. Residues from evaporation or heating can explode spontaneously. In some cases the peroxides thus formed can cause polymerization. Peroxides are normally rendered harmless with iron (II) sulfate or by passing the liquid over a bed of activated aluminum oxide (see Data Sheet 1-655-rev. 82 of the National Safety Council). 

PVC is manufactured by three routes bulk (or mass), suspension, and emulsion polymerization using free radical initiators (section 1.8.1). In the bulk polymerization using liquid vinyl chloride monomer (VCM), the polymerization is usually done in two stages at 60 °C. Pre-polymerization to about 10% conversion yields a viscous suspension (PVC is insoluble in VCM) which is then added to a second horizontal reactor (together with more monomer and peroxide catalyst) with slowly rotating agitator blades. The mixture at 25% conversion becomes a powder. 

CH2=CHC = CCH = CH2. a colourless liquid which turns yellow on exposure to the air it has a distinct garlic-like odour b.p. 83-5°C. Manufactured by the controlled, low-temperature polymerization of acetylene in the presence of an aqueous solution of copper(I) and ammonium chlorides. It is very dangerous to handle, as it absorbs oxygen from the air to give an explosive peroxide. When heated in an inert atmosphere, it polymerizes to form first a drying oil and finally a hard, brittle insoluble resin. Reacts with chlorine to give a mixture of chlorinated products used as drying oils and plastics. 

Vinyl acetate -8 CH3C00CH CH2 427 2.6-13.4 1.1 3.0 72 Colourless, partially water soluble liquid Faint odour Polymerizes with heat or organic peroxides... 

Can polymerize exothermically with strong alkalis, heat or light Can form peroxides Colourless, wrater soluble liquid... 

Must be inhibited Colourless, partially water soluble liquid Experimental carcinogen Polymerizes violently with organic peroxides or concentrated caustic alkalis... 

Acetaldehyde (Acetic aldehyde, ethanal) CHjCHO -38 185 4.0-55.0 0.8 1.5 21 Colourless fuming liquid Pungent odour Irritant Water soluble Can polymerize exothermically, form explosive peroxides, or react violently with other chemicals... 

Acrolein Allyl aldehyde, propenal) CH2 CHCHO -26 278 2.8-31.0 0.8 1.9 53 Colourless/yellow liquid Pungent unpleasant odour Water soluble Irritant Can polymerize exothermically with strong alkalis, heat or light Can form peroxides... 

Acrylonitrile (Vinyl cyanide, propenenitrile) CH2 CHCN 0 481 3.0-17.0 0.8 1.8 77 Colourless, partially water soluble liquid Experimental carcinogen Polymerizes violently with organic peroxides or concentrated caustic alkalis Highly toxic Usually inhibited... 

Butadiene (Butadiene, vinylethylene) CH2 CHCH CH2 -76 450 2.0-11.5 0.6 1.9 -4 Colourless, odourless liquefiable gas Polymerizes readily, particularly if 02 or traces of catalyst present Can form explosive peroxides Normally contains inhibitor (liquid phase) and antioxidant... 

Ethyl acrylate CH2 CHCOOC2H5 15 - 1.8- - 1.2 100 Colourless liquid Acrid odour Polymerizes readily, accelerated by heat, light, organic peroxides Irritant... 

Colorless to greenish-yellow liquid with a pungent, piercing, disagreeable odor detectable at 0.3 ppm. Unstable and prone to polymerization often stabilized with amyl nitrate or hydroquinone. May form shock-sensitive peroxides during storage. 

The bone cement used in these studies was a two-component system. The liquid component [9.75 mL methyl methacrylate (MMA) 0.25 mL A,A-dimethyl-p-toluidine (DMPT) 75 mg/kg hydroquinone] was mixed with a solid component [3.0 g poly(methyl methacrylate) (PMMA) 15.0 g MMA-styrene copolymer benzoyl peroxide, mass fraction 2% 2.0 g BaSOJ to form the cement. Dissolution of the solid component proceeded simultaneously with polymerization once the cement was mixed. 

Chemical/Physical. Slowly polymerizes with time into a viscous liquid (Windholz et al., 1983). Polymerization may be caused by elevated temperatures, oxidizers, or peroxides (NIOSH, 1997). 

A number of flammable liquids and gases used in processing facilities are stored in refrigerated vessels. Common among these are liquefied gases, such as liquefied natural gas (LNG) and anhydrous ammonia, and a number of reactive or self-polymerizing liquids, such as acrylic acid and organic peroxides. 

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