Chlorinated Polyethylene (CPE) in PVC

Chlorinated Polyethylene (CPE) is an important additive for the production of Polyvinyl Chloride (PVC). It is used as an impact modifier and can improve the mechanical properties of the end product. Here, we will examine the properties of CPE as an impact modifier in PVC, its advantages, and limitations.

Properties of Chlorinated Polyethylene

Chlorinated Polyethylene is a thermoplastic polymer produced by chlorinating High-Density Polyethylene (HDPE). Chlorination transforms the polyethylene into CPE, altering its properties. CPE exhibits good impact resistance, stiffness, weather resistance, and chemical resistance. It is also highly resistant to UV radiation and ozone.

Advantages of Chlorinated Polyethylene as an Impact Modifier in PVC

When CPE, like our Addforce Mod 135A, is used as an impact modifier in PVC, it significantly enhances the mechanical properties of the PVC product.

The soft, rubber-like Chlorinated Polyethylene (CPE) is embedded in the PVC matrix, thereby increasing impact resistance.

CPE ensures optimal impact resistance, higher fracture toughness, and stable stiffness. Additionally, CPE exhibits greater weather resistance compared to unmodified PVC.

As a modifying agent, CPE, like our Addforce CM 3680, is used in semi-rigid PVC cable sheathing. Here, CPE improves properties at low temperatures (e.g., reducing brittleness) and reduces the amount of plasticizers. CPE grades can be blended with plastics such as PVC, polyolefins, ABS, and elastomers like NBR, EPDM. Our Addforce FR 1035 enhances flame resistance and impact resistance in ABS and PU.

CPE is often used as a substitute for Acrylonitrile-Butadiene-Styrene Copolymer (ABS) because it offers similar impact resistance and stiffness. However, CPE is more cost-effective than ABS and can be used in a wider range of applications.

Limitations of Chlorinated Polyethylene as an Impact Modifier in PVC

Despite the many advantages of CPE as an impact modifier in PVC, there are also some limitations. One of the main issues is that CPE tends to migrate, meaning it can leach out of the PVC product. This can lead to problems such as poor adhesion and surface defects.

Furthermore, CPE may also cause issues when reacting with other additives or stabilizers in PVC. For example, when used with lead or tin stabilizers, it can cause discoloration or degradation of the PVC.

Conclusion

Chlorinated Polyethylene is an important additive for the production of PVC products as it can improve the mechanical properties of the end product. It has many advantages, including increased impact resistance, fracture toughness, and weather resistance. However, there are also limitations that need to be considered, including migration and potential reactions with other additives and stabilizers in PVC. Overall, CPE remains a crucial additive for producing high-quality PVC products.

Potential applications include:

• PVC > Rigid PVC (profiles, sheets)
• Rubber > Synthetic rubber
• Building and constructions > Roofing, membranes
• Engineering/Manufacturing > Belts, conveyor belts
• Pipes, hoses, and fittings > Pipes
• Wiring & cables
• Sealing components