Barium-Cadmium based Stabilizers

The highly developed synergistic Ba/Cd stabilizer system for rigid vinyl use in exterior applications is the result of long lasting efforts in this field. By itself, cadmium carboxylate is ineffective because developing cadmium chloride acts as a strong Lewis acid and accelerates the decomposition of PVC. Barium carboxylate converts cadmium chloride formed back into the cadmium carboxylate. Addition of a chelating agent decidedly improves the stability of PVC. A certain ratio of Ba/Cd stabilizer must be retained; best ratio is 6 to 1. The addition of epoxidized soybean oil further improves both heat and light stability of these systems.