Aliphatic hydrocarbons chlorinated ethylenes

Such xenobiotics as aliphatic hydrocarbons and derivatives, chlorinated ahphatic compounds (methyl, ethyl, methylene, and ethylene chlorides), aromatic hydrocarbons and derivatives (benzene, toluene, phthalate, ethylbenzene, xylenes, and phenol), polycyclic aromatic hydrocarbons, halogenated aromatic compounds (chlorophenols, polychlorinated biphenyls, dioxins and relatives, DDT and relatives), AZO dyes, compounds with nitrogroups (explosive-contaminated waste and herbicides), and organophosphate wastes can be treated effectively by aerobic microorganisms. 

The principal polyolefins are low-density polyethylene (ldpe), high-density polyethylene (hope), linear low-density polyethylene (lldpe), polypropylene (PP), polyisobutylene (PIB), poly-1-butene (PB), copolymers of ethylene and propylene (EP), and proprietary copolymers of ethylene and alpha olefins. Since all these polymers are aliphatic hydrocarbons, the amorphous polymers are soluble in aliphatic hydrocarbon solvents with similar solubility parameters. Like other alkanes, they are resistant to attack by most ionic and most polar chemicals their usual reactions are limited to combustion, chemical oxidation, chlorination, nitration, and free-radical reactions. 

Halogenated Aliphatic Hydrocarbons. The best-known examples are methylene dichloride, chloroform, and carbon tetrachloride, although chlorinated ethylenes are also widely used. 

Aliphatic hydrocarbons possess a high foaming efficiency and they are nontoxic. However, they are highly inflammable and safety precautions must be taken by the producers this is a severe limitation to their use. Chlorinated hydrocarbons do not present the flammability problem and they are largely used as physical blowing agents. For instance, chlorinated ethylenes are recommended to foam PVC and epoxy resins. 

The two-component organometallic catalyst MeTiClj—MeAlCU [90,91 [, which is distinct from other Ti-Al systems, shows the following order of activity for the dimerization of ethylene in organic solvents chlorinated hydrocarbons > aromatic hydrocarbons > aliphatic hydrocarbons. It exists as the following struc-mral formulas ... 

Poly(ethylene terephthalate). DMSO (hot), halogenated aliphatic esters, chlorinated hydrocarbons. 316... 

The fluids have reasonably good chemical resistance but are attacked by concentrated mineral acids and alkalis. They are soluble in aliphatic, aromatic and chlorinated hydrocarbons, which is to be expected from the low solubility parameter of 14.9 MPa. They are insoluble in solvents of higher solubility parameter such as acetone, ethylene glycol and water. They are themselves very poor solvents. Some physical properties of the dimethylsilicone fluids are summarised in Table 29.2. 

O2) or (CIF3 + water). Potentially explosive polymerization reaction with ethylene. Incompatible with 1,1-dichloroethylene oxygen. When heated to decomposition it emits toxic fumes of F and CL. See also CHLORINATED HYDROCARBONS, ALIPHATIC and FLUORIDES. 

Flammable gas. Very dangerous fire hazard when exposed to heat, flame, or powerful oxidizers. Moderate explosion hazard when exposed to flame and sparks. Explodes on contact with interhalogens (e.g., bromine trifluoride, bromine pentafluoride), magnesium and alloys, potassium and alloys, sodium and alloys, zinc, Potentially explosive reaction with aluminum when heated to 152° in a sealed container. Mixtures with aluminum chloride + ethylene react exothermically and then explode when pressurized to above 30 bar. May ignite on contact with aluminum chloride or powdered aluminum. To fight fire, stop flow of gas and use CO2, dry chemical, or water spray. When heated to decomposition it emits highly toxic fumes of cr. See also CHLORINATED HYDROCARBONS, ALIPHATIC. 

Poly(methyl methacrylate) prepared by free radical polymerization is amorphous and is therefore soluble in solvents of similar solubility parameter. Effective solvents include aromatic hydrocarbons such as benzene and toluene chlorinated hydrocarbons such as chloroform and ethylene dichloride and esters such as ethyl acetate and amyl acetate. Some organic materials, although not solvents for the polymer, cause crazing and cracking, e.g., aliphatic alcohols and amines. Poly(methyl methacrylate) has very good resistance to attack by water, alkalis, aqueous inorganic salts and most dilute acids. Some dilute acids such as hydrocyanic and hydrofluoric acids, however, do attack the polymer, as do concentrated oxidizing acids. Poly(methyl methacrylate) has much better resistance to hydrolysis than poly(methyl acrylate), probably by virtue of the... 

In general, amorphous polyamides are somewhat less resistant and more prone to stress-cracking than semi-crystalline polyamides, Table 5.93. Amorphous, partially aromatic polyamides are resistant to gasoline, benzene, paraffin oil, aliphatic and aromatic hydrocarbons, ketones, dilute hydrochloric acid, dilute sulfuric acid, aqueous salt solutions, dilute caustic soda, and formaldehyde. They are not resistant to ethanol, propanol, butyl alcohol, ethylene glycol, propylene glycol, chlorinated hydrocarbons, concentrated mineral acid, and formic acid. 

Liquid polysulfides can also be prepared directly with thiol end groups by reacting a mixture of aliphatic di- and polyhalides with a mixture of sodium disulfide and sodium hydrogen sulfide [77]. Reaction polymeric disulfides with polymercaptans also leads to the formation of liquid polysulfides [37]. LP polymers with M in the range of 600 to 8000 are generally f eferred. The uncured LP polymers are soluble in toluene, benzene and chlorinated hydrocarbons such as ethylene chloride [17, 78]. LP polym like LP-31, LP-2, LP-32, LP-12, LP-3, LP-33, LP-5, LP-8, based on range of viscosities, molecular weights and functionalities, are available [17]. 

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