how are polychlorinated biphenyls made?
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PCB Mixtures and Trade Names With few exceptions, PCBs were manufactured as a mixture of individual PCB congeners. These mixtures were created by adding progressively more chlorine to batches of biphenyl until a certain target percentage of chlorine by weight was achieved.
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Lead Perchlorate, Pb(ClO4)2. 3H2O, is formed, not by ignition of the chlorate, but by dissolving lead oxide or carbonate in aqueous perchloric acid. It crystallises in soluble, white needles, which hold their water very tenaciously.
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Paper cups are made from wood chips. The chips are turned into wood pulp, which is mashed into paper. The Royal Society of Chemistry estimates 33 grams of wood and bark go into each paper cup. The pulp is bleached using chlorine, sodium hydroxide and other chemicals.
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Neoprene (CR), also called polychloroprene or chloroprene rubber, synthetic rubber produced by the polymerization (or linking together of single molecules into giant, multiple-unit molecules) of chloroprene.
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The compounds of chlorine include Gammaxene, DDT and bleaching powder.
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DDT is formed when two mole chloro benzene and one mole chloral are reacting. In the existence of sulfuric acid, one mole of chloral with two moles of chlorobenzene together reacts to produce the DDT (Dichlorodiphenyltrichloroethane).
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Toxic byproducts Fires to energized electrical equipment would not only cause vapors from burning PCBs to be released into the air, but a highly toxic byproduct of burning PCBs, polychlorinated dibenzo-p-dioxins dioxins.
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The materials used to manufacture most pads are derived from the petroleum industry and forestry. The absorbent core, made from chlorine bleached wood pulp, could be reduced to make slimmer products with the addition of polyacrylate gels which sucks up the liquid quickly and holds it in a suspension under pressure.
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PCB congeners are non-polar compounds that separate predominantly on boiling point when analysed on a 5% phenyl column. Because of the similar structures of many of the PCBs, the boiling points are very similar and many of the congeners are unable to be separated on non-polar columns.
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Burning: Dioxins are formed as a result of combustion processes such as waste incineration (commercial or municipal) or from burning fuels (like wood, coal or oil). ... You may not be aware that dioxins can also be formed when household trash is burned or from events like forest fires.
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CFCs and HCFCs are usually produced by halogen exchange starting from chlorinated methanes and ethanes. Illustrative is the synthesis of chlorodifluoromethane from chloroform: HCCl3 + 2 HF → HCF2Cl + 2 HCl.
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The Process of Making HDPE HDPE is made under controlled conditions by applying intense heat to petroleum. This process, also known as “cracking,” helps create ethylene gas. During its production, the gas molecules will attach to form polymers, which then produce polyethylene.
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In general, PCBs are relatively insoluble in water, and the solubility decreases with increased chlorination (see Table 4-3). PCBs are also freely soluble in nonpolar organic solvents and biological lipids (EPA 1980b).
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PCBs: PolyChlorinated Biphenyls, are a group of organic chemicals which can be odorless or mildly aromatic solids or oily liquids. ... This law requires the Environmental Protection Act (EPA) to determine safe levels of chemicals in drinking water which do or may cause health problems.
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Bisphenol A (BPA) is an organic compound used in the manufacturing of many types of plastic, such as water bottles, sports equipment and CDs. ... If you are buying PLA bottles, you want to compost them or throw them in the garbage instead of recycling them, unless your recycling program accepts #7 plastics.
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Plastic bags can be made "oxo-biodegradable" by being manufactured from a normal plastic polymer (i.e. polyethylene) or polypropylene incorporating an additive which causes degradation and then biodegradation of the polymer (polyethylene) due to oxidation.
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Scientists make plastic from pine trees. ... Caprolactone is made from crude oil, and so the resulting plastic isn't totally renewable. The researchers publishing their results in the journal Polymer Chemistry, used pinene as the raw material to make a new type of plastic that can be used in the place of caprolactone.