Calcium-zinc stabilizers are environmentally friendly, high-performance non-lead thermal stabilizers widely used in PVC plastic products. Their core advantage lies in achieving thermal stability, oxidation resistance, and lubrication through the synergistic action of calcium salts and zinc salts, while meeting green chemistry requirements. This makes them an eco-friendly alternative to traditional lead-based stabilizers.
Composition and Mechanism of Action
Calcium-zinc stabilizers primarily consist of calcium salts (e.g., calcium stearate) and zinc salts (e.g., zinc stearate) along with their complexes. They ensure PVC processing stability through multiple mechanisms:
Degradation Inhibition: PVC undergoes dehydrochlorination reactions during high-temperature processing, causing discoloration and embrittlement. Calcium-zinc stabilizers capture free chlorine ions, halting chain degradation reactions and preserving material structural integrity.
Antioxidant Properties: Zinc salts neutralize free radicals generated during processing, delaying oxidative aging and extending product lifespan.
Lubrication Effects: Stearate components provide internal lubrication, reducing PVC melt viscosity, improving processing flowability, and minimizing equipment wear.