Chlorinated polyethylene (PE-C or CPE) is a polymer produced by chlorination of polyethylene in an environment of organic solvents. It is a polyethylene in which chlorine atoms replace hydrogen atoms. This polymer can be either a rigid thermoplastic or a flexible elastomer, which makes it versatile for many areas of production.
Polyethylene, in which up to 15% of hydrogen is replaced by chlorine, retains the properties of thermoplastics. With an increase in the degree of chlorination, it gradually turns into thermoplastic elastomer, rubber, leather-like hard material, and, with a degree of substitution of 71-75%, becomes a brittle and soluble resin.
Chlorine-substituted polyethylene can be used as a base material in various industries, and it is also used to make:
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the outer shell for wires and cables
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roofing and siding
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PVC products
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automotive and industrial hoses and tubes
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molded products
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extrudates (extrusion products)
Properties of chlorinated polyethylene
Chlorinated polyethylene is a non-toxic powder of white or pale yellow color, odorless, has excellent resistance to atmospheric or ozone influences, non-toxic, non-flammable. Compatible with many pigments.
The material provides the following properties to the products made from it:
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resistance to ignition, no spontaneous combustion
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chemical resistance
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resistance to high temperatures
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good flexibility at low temperatures
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good stability
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ease of processing and shaping
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residual deformation during compression
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tensile strength
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abrasion resistance
The use of chlorinated polyethylene
CPE can be used as a base polymer or as an additive to polyvinyl chloride, styrene-acrylonitrile and polypropylene for a wide range of applications covering both thermoplastic and thermosetting substances.
Due to its soft elastic texture, substituted polyethylene is added to polyvinyl chloride for its weather resistance. It is also used to soften PVC film without the risk of plasticizer migration.
Substituted polyethylene is widely used as impact resistance modifiers in PVC extrusion and injection molding. It is especially effective in the production of window profiles, pipes and siding. CPE provides excellent corner seam strength and excellent surface gloss.
Chlorinated polyethylene can be crosslinked with peroxides to form an elastomer, which is used in the cable and rubber industries. When chlorinated polyethylene is added to other polyolefins, their flammability decreases.
The use of CPE in a mixture with polyvinyl chloride
Often substituted polyethylene is used as a modifier, which increases impact resistance and reduces the cost of rigid and brittle (non-plasticized) PVC.
Construction products made from this type of polyethylene:
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taps for rainwater
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underground drainage
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profiles
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doors
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windows
There are 2 main types of PVC:
Rigid PVC, which is used in the manufacture of pipes and plastic products
Flexible PVC, which consists of a polymer with the addition of plasticizers
This type of PVC (flexible) is used for the manufacture of films, coatings and artificial leather, has disadvantages such as low thermal stability and fragility. PVC without any additives at room temperature is a tough material. It is often used instead of glass. But if it is heated above a temperature of 87 ° C, the polymer becomes flexible and rubbery. Compared to polyethylene and polypropylene, unmodified PVC is more rigid, durable and more sensitive to solvents. PVC competes with rubber in many areas of production due to its excellent properties:
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High electrical insulation
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High abrasion resistance
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Low diffusion for humidity
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Good flexibility over a wide temperature range
The influence of chlorinated polyethylene on its mechanical properties has been actively studied in recent years due to the high demand for PVC. Experimental results have shown that the strength of the material can be increased by the introduction of chlorinated polyethylene (CPE). The impact strength of PVC/CPE hybrids is also increased compared to pure PVC.