Low-Frequency NMR Relaxometry Studies of Composite Cylinders with EPDM Insulation

Composite cylinders with protective insulation layers are being used for many industrial applications including usage under special environmental conditions. The insulation materials such as Rocasin and EPDM are specifically designed and processed for achieving properties to withstand environmental conditions. In this study, low frequency NMR (13.35 MHz) has been used for performing relaxometry studies to ascertain the bond quality of insulation with composite materials as well as to verify the thickness of the bonded insulation layer which otherwise cannot be done using available physical methods. Initially, studies were performed on flat composite samples bonded with insulation layers (Rocasin and EPDM). The results on flat samples were later compared with the cylindrical samples with same insulation layers. Paper also reports the study of relaxation times of EPDM insulation for characterization and chemical identification useful for quality control of materials during bulk manufacturing of composite cylindrical structures used in oil and pipe line industry.