The inter-face between covulcanized rubber sheets by NMR imaging, scanningFTIR spectroscopy, and mechanical indentation mapping

Depending on compounds and vulcanization conditions on interface can be det ected between covulcanized rubbers sheets which exhibits properties differe nt fi om either of the pure compounds. This interface has been analyzed in NR/SBR covulcanizates by different techniques of NMR imaging including spec troscopic imaging to differentiate different chemical compounds. These inve stigations were complemented by scanning Fourier infrared spectroscopy and mechanical indentation mapping. The current understanding is that the inter face is harder than the SBR and NR regions and typically of the order of 20 0 mu m thick.