Chlorinated Polyethylene (CPE) is a remarkable polymer known for its adaptability and a broad spectrum of desirable properties. Its performance characteristics are largely influenced by the degree of chlorination, which dictates its behavior from a rigid plastic to a flexible elastomer. Understanding these properties is fundamental for material scientists and manufacturers aiming to select the most suitable grade for their specific applications, whether it's for PVC modification or use as a standalone synthetic rubber.

The physical state of CPE is typically a white, non-toxic, and odorless powder. Its density usually ranges between 0.93 to 0.96 g/cm³. However, the most significant determinant of its properties is its chlorine content, which can vary significantly. For instance, when the chlorine content is below 15%, CPE behaves more like a plastic. As the chlorine content increases to between 16% and 24%, it starts exhibiting thermoplastic elastomer properties. Crucially, with a chlorine content between 25% and 48%, CPE functions as a rubber-like elastomer, making it highly valuable for applications requiring flexibility and resilience. Different suppliers offer various grades, such as CPE135A, which typically has a chlorine content of around 35%, balancing impact modification with processability.

In terms of chemical resistance, CPE stands out. It demonstrates excellent resistance to oils, especially ASTM No. 2 and No. 3 oils, often comparable to or better than nitrile rubber (NBR) and chlorosulfonated polyethylene (CSM). This makes CPE a preferred choice for applications exposed to lubricants, fuels, and other petroleum-based products, such as automotive hoses and industrial seals. Furthermore, its resistance to acids, alkalis, and salts enhances its applicability in corrosive environments.

Mechanical properties are another area where CPE excels. It offers good toughness, even at low temperatures (down to -30°C for some grades), and maintains good tensile strength and elongation at break. The material also boasts good thermal stability, though it decomposes upon heating, releasing HCl, which can sometimes catalyze further reactions. Its resistance to aging, both thermal and oxidative, is also noteworthy, contributing to the longevity of products made from or modified with CPE.

Flame retardancy is an inherent characteristic of CPE due to its chlorine content. This property is highly desirable in many applications, particularly in wire and cable sheathing, and construction materials, where fire safety is a critical concern. CPE can also be formulated with other flame retardants to achieve even higher levels of fire resistance.

The processing of CPE, whether as a standalone material or as an additive, is generally straightforward. It exhibits good compatibility with other polymers, particularly PVC, and has excellent filler acceptance, allowing for cost-effective formulations without compromising performance. When sourcing CPE, understanding the specific technical data, such as bulk density, volatile matter content, and particle size, from reputable manufacturers is essential for successful implementation.

In conclusion, the diverse properties of Chlorinated Polyethylene (CPE), driven by its chlorine content and polymer structure, make it an indispensable material for enhancing product performance. Its excellent oil resistance, flame retardancy, weatherability, and mechanical strength, particularly at low temperatures, ensure its continued importance in various industrial sectors. Material selection should always be guided by a thorough understanding of these properties and consultation with knowledgeable suppliers.