Chlorinated Polyolefin

Chlorinated Polyolefin 

a synthetic polymer; a chlorinated product of polyethylene or polypropylene.

Chlorinated polyolefins are noted for their varied properties, which depend on the type, molecular weight, and structure of the initial polymer, as well as on the method of chlorine addition and the chlorine content. For example, chlorinated polyethylene products containing up to 15 percent chlorine are plastics; 16 to 25 percent, thermoelastic plastics; 26 to 48 percent, elastomers (rubber); 49 to 60 percent, stiff, leather-like materials; and 61 to 75 percent, brittle resins. Those containing 61 to 70 percent chlorine have properties similar to the properties of polyvinyl chloride. The density of chlorinated polyethylene products varies from 0.92 to 1.61 g/cm³. The tensile strength of highly chlorinated polyethylene and polypropylene products reaches 25 and 32 meganewtons/m² (250 and 320 kilograms-force/cm²), respectively.

Among the valuable properties of all chlorinated polyolefins are good adhesion to various surfaces and resistance to fire. Chlorinated polyethylene products are also resistant to the action of ozone, oxygen, alkalies, saline solutions, strong acids, aliphatic hydrocarbons, alcohols, oils, and gasoline; they are somewhat less resistant to chlorinated aromatic hydrocarbons. On exposure to light and heat, chlorinated polyolefins can split off HCl, and consequently they require stabilization (seeSTABILIZER OF POLYMER PLASTICS).

Chlorinated polyethylene products are used in the manufacture of transparent films for medical, household, and agricultural uses. Chlorinated polyethylene elastomers are ingredients in the manufacture of rubber products used in technology; mixed with polyvinyl chloride, they are used in the manufacture of fire- and frost-resistant plastics. Chlorinated polypropylene products are processed into fibers and strong transparent films. Polyethylene and polypropylene products containing 50–70 percent chlorine are used as binders in paints and varnishes and as bases for various adhesives and coatings.

The foreign trade names for chlorinated polyethylene polymers are Tyrin (United States), Haloflex (Great Britain), Hostalen (Federal Republic of Germany), and Elaslen (Japan). Perlon P is the trade name used in the United States for chlorinated polypropylene polymers.

In 1976 the world production of chlorinated polyolefins amounted to approximately 80,000 tons.

REFERENCE

Entsiklopediia polimerov, vol. 3. Moscow, 1977.

G. M. RONKIN