THE EFFECTS OF METAL-OXIDES ON BLOCKED DIAMINE CURE OF ACRYLIC RUBBERIN PRESENCE AND ABSENCE OF FILLERS

Effects of metal oxides (viz., PbO, PbO2 and CdO) on N,N-dicyaneamylid ene-1,6-hexanediamine (Diak No. 3) cure of acrylic rubber (ACM) have b een evaluated with a view to elucidate the crosslinking mechanism with special reference to the role of metal oxides. Carbon black (SRF) and calcium carbonate (CaCO3) have been used as fillers. Best results are obtained with PbO in the presence of Diak No. 3. SRF acts as better r einforcing filler than CaCO3. The formation of metal chlorides during crosslinking reaction has been confirmed by X-ray diffraction (XRD) an d X-ray photoelectron spectra (XPS) analysis. Examination of FTIR spec tra reveals that crosslinking occurs at the C-Cl cure site of polymer. Based on spectral analysis a reaction mechanism has been put forward.