N′‐acryloyl benzhydrazide as a thermal stabilizer for rigid poly(vinyl chloride)

N′‐Acryloyl benzhydrazide (ABH) was examined as a thermal stabilizer and costabilizer for rigid poly(vinyl chloride) (PVC) in air at 180°C. Its high stabilizing efficiency was shown by its high thermal stability value (T_s) when compared with those of two common reference stabilizers used industrially, dibasic lead carbonate (DBLC) and a calcium–zinc soap. Blending this organic stabilizer with the reference stabilizers in different ratios had synergistic effects on both the thermal stability and the extent of discoloration of the PVC. The Ni²⁺ complex of ABH gave better thermal stability and lesser discoloration than the parent organic stabilizer. Also, blending that complex with DBLC in different ratios gave better stability and lower discoloration. Thermogravimetric analysis confirmed the improved stability of PVC in the presence of the ABH stabilizer. J. VINYL ADDIT. TECHNOL., 2008. © 2008 Society of Plastics Engineers.