Polymerization, organic compounds

Wood and, polymers. Natural materials as well as materials manufactured from plant or animal origin, such as wood, cotton, paper products, wool, and leather, etc., are fully biodegradable under aerobic conditions. (Dexter)5 Plastics are materials that consist mainly of highly polymeric, organic compounds. Also, nondegradable polymer may become degradable by a combined chemical, physical, and biological attack.64,67... 

Polymeric organic compounds Polyethylene (- CH2 -) and many others. 

The enzymatic hydrolysis of polymeric organic compounds results in production of several monomers, including glucose, xylose, fatty acids, and amino acids. The chemical energy stored in these reduced compounds is released upon their oxidation, resulting in release of electrons. 

The concentrations of i° Ag and noni g oysters, cultivated in nearly closed bays, were remarkably lower than in open bays in the same samphng time. This trend was especially clear ° in the Chemobyl-derived " " Ag. In an open bay 2780 [mBq/(kg flesh)] of 110 Ag was detected in late 1986, 710 mBq/kg flesh in the inlet to a nearly closed bay and less than the detection hmit at the end of this bay, in the same sampling time. The concentrations of i Cs in oysters cultivated in the open and nearly closed bays were similar. This has been related to the ionic chemical form of Cs soluble in sea water i, while silver is combined with highly polymeric organic compounds such as proteins or proteincarbohydrates. 

Some pre-treatments provide extra nuclei upon which zinc phosphate crystals can be deposited, resulting in finer and more even coatings. Colloidal Ti or Zr phosphates have been used for this, and also phosphoric acid formulations containing -0.1% of polymeric organic compounds [11]. 

Plastics are materials that consist mainly of highly polymeric, organic compounds. These are manufactured by chemical synthesis and/or by the transformation of natural products. Most plastics are moldable and formable (thermoplasts). The properties of plastics can be modified by mixing them with additives of different kinds. 

MERISATION. Chemical terms are seven-digit alphanumeric Du Pont accession numbers or C-Numbers, and each represents an individual chemical substance, including polymers. A C-Number is assigned sequentially to each unique substance entered into the system, and it links a series of files used for identification, document referencing, and classification of substances. Non-polymeric organic compounds are stored as compact connection tables based on topology descriptors, which resemble chemical fragments, are also part of the record. Polymeric substance records consist of C-Numbers of component monomers as well as polymer class descriptors where applicable. 

Solution Polymerization. Solution polymerization is widely used ia the acryhc fiber iadustry. The reactioa is carried out ia a homogeaeous medium by usiag a solveat for the polymer. Suitable solveats can be highly polar organic compounds or inorganic aqueous salt solutions. 

Aqueous mineral acids react with BF to yield the hydrates of BF or the hydroxyfluoroboric acids, fluoroboric acid, or boric acid. Solution in aqueous alkali gives the soluble salts of the hydroxyfluoroboric acids, fluoroboric acids, or boric acid. Boron trifluoride, slightly soluble in many organic solvents including saturated hydrocarbons (qv), halogenated hydrocarbons, and aromatic compounds, easily polymerizes unsaturated compounds such as butylenes (qv), styrene (qv), or vinyl esters, as well as easily cleaved cycHc molecules such as tetrahydrofuran (see Furan derivatives). Other molecules containing electron-donating atoms such as O, S, N, P, etc, eg, alcohols, acids, amines, phosphines, and ethers, may dissolve BF to produce soluble adducts. 

Researchers at Phillips Petroleum Company developed a commercially viable process for the synthesis of PPS involving the polymerization of /)-dich1orohenzene and a sodium sulfide source in a polar organic compound at elevated temperature and pressure. This Phillips process was patented in 1967 (18). Between 1967 and 1973, Phillips built and operated a pilot plant, estabhshed market demand, and constmcted a hiU-scale commercial plant. In 1973, the world s first PPS plant came on-stream in Phillips faciUty in Borger, Texas. 

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