THE ROLE OF METAL-OXIDES IN AMMONIUM BENZOATE CURING OF POLYACRYLIC RUBBER BOTH IN PRESENCE AND ABSENCE OF FILLERS

Effects of metal oxides (viz. PbO, PbO2 and CdO) on ammonium benzoate cure of polyacrylic rubber (ACM) have been evaluated with a view to el ucidate the curing mechanism with special reference to the role of met al oxides. Carbon black (SRF), calcium carbonate (CaCO3) and silica (S iO2) have been used as fillers. Best results are obtained with PbO in the presence of ammonium benzoate. SRF acts as better reinforcing fill er than both CaCO3 and SiO2. The formation of metal chloride during cu ring has been confirmed by XRD and XPS. Examination of FTIR spectra re veals that crosslinking occurs at the C-Cl cure site of the polymer. B ased on spectral analysis a reaction mechanism has been put forward.