Plastics manufacturing, chemicals used ethylene

Industrial ethanol is one of the largest-volume organic chemicals used in industrial and consumer products. The main uses for ethanol are as an intermediate in the production of other chemicals (Table 8) and as a solvent. As a solvent, ethanol is second only to water. Ethanol is a key raw material in the manufacture of dmgs, plastics, lacquers, poHshes, plasticizers, perfumes, and cosmetics. Around 1960, manufacture of ethanol was the top consumer of ethylene in the United States, but since 1965 it has rated below manufacture of ethylene oxide and polyethylene. 

Bromine occurs in nature as bromide in many natural brine wells and salt deposits. It also is found in seawater at a concentration of 85 mg/L. The element was discovered by A. J. Balard and C. Lowig, independently in 1826. Bromine is used in bleaching fibers and as a disinfectant for water purification. Other appbcations are in organic synthesis as an oxidizing or brominat-ing agent in the manufacture of ethylene dibromide, methyl bromide and other bromo compounds for dyes and pharmaceutical uses as a fire retardant for plastics and in chemical analysis. Ethylene dibromide is used in anti-... 

Ethylene The simplest alkane hydrocarbon, consisting of two carbon atoms and four hydrogen atoms. Ethylene is primarily an intermediate chemical used in the manufacture of other chemicals, especially plastics. 

Polymers are important. Approximately 60 million tonnes are made annually. Indeed most of the organic chemicals manufactured are used to make polymers. These chemicals obviously include monomers, but indirectly the polymer industry consumes enormous quantities of organic materials for solvents, antioxidants, stabilizers, plasticizers etc. Apart from fuel (for transport and heat) and speciality chemicals like ethylene glycol (anti-freeze), pharmaceutical and agrochemicals etc., it can be stated that the end-use of most organic chemicals is in the production, directly or indirectly, of polymers. 

Ethylene finds use in the manufacture of ethyl benzene, ethanol, ethylene oxide, ethylene glycol, and ethylene dichloride. About half of the ethylene produced in the United States is used for the production of high- and low-density polyethylene plastics. Other chemical raw materials made with ethylene include ethyl chloride, dichloroethane, vinyl chloride, ethyl ether, methyl acrylate, and styrene. 

A.luminum Jilkyl Chain Growth. Ethyl, Chevron, and Mitsubishi Chemical manufacture higher, linear alpha olefins from ethylene via chain growth on triethyl aluminum (15). The linear products are then used as oxo feedstock for both plasticizer and detergent range alcohols and because the feedstocks are linear, the linearity of the alcohol product, which has an entirely odd number of carbons, is a function of the oxo process employed. Alcohols are manufactured from this type of olefin by Sterling, Exxon, ICI, BASE, Oxochemie, and Mitsubishi Chemical. 

One of the most important reactions in the chemical industry is the cracking (removing hydrogen) of paraffins to form olefins. Olefins are essential starting materials for many common products that we all use, particularly plastics. The simplest olefin is ethylene, which can be polymerized (reacted many times with itself) to give po/yethylene used for bottles, dishware, film, etc. The next higher olefin, propylene, can be polymerized to polypropylene used in the manufacture of rugs, toys, kitchenware, and many other plastic objects. Note that the names of olefins end in -ene, which denotes the presence of a double bond in the compound. 

Ethylene is a colorless, flammable gas with a boiling point of-104 °C. More than 22 billion kilograms of ethylene are produced annually in the United States, making it one of the top five industrial chemicals. The manufacture of plastics (polyethylene is the most common example) consumes 75% of this output, and much of the rest is used to make antifreeze. Because ethylene stimulates the breakdown of cell walls. It Is used commercially to hasten the ripening of fruit, particularly bananas. 

Ethylene (structure in Figure 13.1) is the most widely used organic chemical. Almost all of it is consumed as a chemical feedstock for the manufacture of other organic chemicals. Polymerization of ethylene to produce polyethylene is illustrated in Figure 13.4. In addition to polyethylene, other polymeric plastics, elastomers, fibers, and resins are manufactured with ethylene as one of the ingredients. Ethylene is also the raw material for the manufacture of ethylene glycol antifreeze, solvents, plasticizers, surfactants, and coatings. 

Propylene (C3H6) is a gas with chemical, physical, and toxicological properties very similar to those of ethylene. It, too, is a simple asphyxiant. Its major use is in the manufacture of polypropylene polymer, a hard, strong plastic from which are made injection-molded bottles, as well as pipes, valves, battery cases, automobile body parts, and rot-resistant indoor-outdoor carpet. 

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