A structural analysis of nitrile rubbers—the 13C resonance technique

This report is concerned with high resolution nuclear magnetic spectroscopy and its value in polymer analysis. A brief description of the technique is provided and the application of the method to a series of nitrile rubbers is reported. It is the unvulcanised rubbers which are analysed and the results obtained provide new information on the nature of the polymer backbone. The results suggest a lower degree of alternation than had previously been supposed. In this paper the polymer backbone is described in terms of monomer triad distributions and data for ten commercial grades of NBR are given. The results reveal distinct differences between nominally similar grades of material offering scope for a clearer insight into the nature of structure-property relationships.