PVC (polyvinyl chloride) is a common thermoplastic polymer that is widely used in the construction industry for pipes, window profiles, and siding, as well as in the manufacturing of medical devices and various consumer goods. However, PVC is inherently unstable and can degrade over time due to exposure to heat, light, and other environmental factors. This degradation can lead to discoloration, embrittlement, and loss of mechanical properties.
To prevent the degradation of PVC, stabilizers are often added to the material during the manufacturing process. One type of stabilizer that is commonly used is a calcium-zinc stabilizer. This type of stabilizer consists of a blend of calcium and zinc salts, which act to neutralize the acidic degradation products that are generated during PVC processing and use.
Calcium-zinc stabilizers offer several advantages over other types of stabilizers, such as lead-based stabilizers, which have been phased out due to environmental and health concerns. Calcium-zinc stabilizers are non-toxic and do not pose the same risks to human health or the environment. They also offer good thermal stability and resistance to UV radiation, making them well-suited for use in outdoor applications.
In summary, a PVC calcium-zinc stabilizer is a type of additive that is used to prevent the degradation of PVC by neutralizing acidic degradation products. It is a non-toxic and environmentally friendly alternative to other types of stabilizers that have been phased out due to health and environmental concerns.