Chlorine-containing plastics

About 10% of the ethylene produced in the U.S. is used to make vinyl chloride, which in the chemical trade is usually referred to as vinyl chloride monomer or VCM. The largest use of VCM is for polymerization to poly(vinyl chloride) (PVC), a thermoplastic, which in terms of volume is second only to polyethylene. PVC is used in such diverse areas as containers, floor coverings (linoleum), plastic pipes, raincoats, and many, many others. PVC has an evironmental disadvantage over non-chlorine containing plastics in that when it is disposed of by incineration it produces hydrogen chloride, which dissolves in atmospheric water to give hydrochloric acid. Polyethylene does not have this undesirable feature. 

As the method is independent of how the atom is attached, chlorine-containing plasticizers such as TCP will interfere with the result if MOCA is used. 

Simplification of the present liquefaction processes by removing several pieces of equipment (for example, the distillation column) will be one important solution. The present complex facilities are necessary to treat chlorine-containing plastics and PET materials from plastic containers and packaging. They provide only small amounts of oil on pyrolysis, but cause various difficulties. The amount of the former materials tends to decrease due to the replacement of PVC and PVDC materials with polyolefins, but the latter is... 

Thermoguard [ATOTECH], TM for antimony-based materials for incorporation in PVC and other chlorine-containing plastics for flameproofing properties. 

As an example, consider a hospital incinerator with a water scrubbing system to clean exhaust gases. Suppose that it is observed that the scrub water contains hydrochloric acid from the burning of chlorine-containing plastics and that this acid is corroding iron drain pipes—a problem that can be eliminated by adding sodium hydroxide to neutralize the acid. The amount of base needed may be determined by titration, a procedure in which a measured volume of the hydrochloric acid-containing scrub solution is reacted with a standard solution of NaOH,... 

The absorption of hydrogen chloride in water (or in dilute HCl) is a very important operation in the manufacture of commercial hydrochloric acid. It is also important in the purification of exhaust gas from chemical operations which form HCl as a by-product, and from refuse incineration where HCl is formed by the combustion of chlorine-containing plastics and solvents. Where HCl vapor is present as an impurity in gas streams, it can readily be removed by washing with water. The only complicating factors are the extreme corrosiveness of the resultant solution and the problem of its disposal. 

Polyvinylidenechloride is another chlorine containing plastic that can be produced in both sheet and fibre forms, though it is not made in anything like the same tonnage as PVC. It has more or less the same property of chemical inertness leading to bonding problems unless the correct adhesive is chosen. 

MITI is currently undergoing research to develop technology for the recycling of non-flammable plastics such as those used in business machines and computers. Their National Institute for Resources and Environment plans to decompose, without the production of harmful substances, non-flammable polymers by means of liquid phase hydrocracking, and to recover from them light oils such as benzene, toluene and xylene. The key to the technology, it is claimed, lies in the development of a catalyst which will be able to combine hazardous substances such as bromine and chlorine contained in the waste plastics. 

ISO 305, Plastics - Determination of thermal stability of poly(vinyl chloride), related chlorine-containing homopolymers and copolymers and their compounds - Discoloration method, 1990. 

If you can wash cloth diapers at home using chlorine alternatives in a washing machine with really hot water, great. Your choice is made. This is an inexpensive (if time-consuming) way of dealing with the diapering dilemma. Sure, you ll use a lot of water, but so do the cloth diaper delivery services, and the manufacturers of disposable diapers. Just try to find diaper covers that aren t plastic or don t contain plastic, especially PVC. There are plenty of (sometimes organic) cotton and wool versions available. 

Interactions during pyrolysis of waste containing plastics in the presence of wood contaminated by chlorine and heavy metals have been studied at laboratory scale. The chlorine capture and the inhibition the chlorination of heavy metals has been validated at pilot scale [1]. 

It has been demonstrated that oil recovered from PVC-containing plastic feedstock can be used as a fuel. Cost is the main obstacle since it requires a large amount of slaked lime to neutralize the HCl gas that is produced by the thermal cracking. Table 15.1 shows the effect that slaked lime has on reducing the chlorine content of fuel oil derived from the pyrolysis of PE (55 wt%), PP (28 wt%) and PS (17 wt%) at a decomposition temperature of 420°C. 

Epichlorohydrin is usually prepared from propene and is mainly used in the manufacture of glycerol and epoxy resins. It is also used in the manufacture of elastomers, glycidyl ethers, cross-linked food starch, surfactants, plasticizers, dyestuffs, pharmaceutical products, oil emulsifiers, lubricants, and adhesives as a solvent for resins, gums, cellulose, esters, paints, and lacquers and as a stabilizer in chlorine-containing substances such as rubber, pesticide formulations, and solvents. 

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