Primary Thermal Stability

Carboxylate replaces allyl chloride and lead chloride will be produced.

Secondary Stability

They react with hydrochloric acid (released during PVC degradation) and form neutral lead chloride.

pbx.nPbo + 2n HCL → nPbCl2 + Pbx + n H2O

Note: Vinyl compounds must be stabilized beyond their capacity so that they remain stable during process condition changes (e.g., in the extruder, temperature, etc.)

or during PVC recycling.

Advantages of Lead-Based Stabilizers

• Low cost
• Provides long-term thermal stability
• Low solubility in water
• Odorless process and product
• Due to their good compatibility with PVC, the migration of these stabilizers out of the polymer is minimal.
• Lead compounds are widely used due to their good processability. They do not affect the Vicat softening temperature of rigid PVC, resulting in good mechanical properties in high-pressure pipes, gas and sewage pipes, and profiles.