OH-functionalized carbon nanotube filled fluoroelastomers aging test in oil based drilling fluids

OH-functionalized carbon nanotube (BCNT)-, carbon nanotube (CNT)-filled fluoroelastomer (FE) and unfilled-FE compounds were prepared (BCNT/FE, CNT/FE and FE). The oil based drilling mud (OBD mud) aging resistances of these elastomers were assessed by tests of AFM, weight gain, swelling and optical microscopy and EDX elemental analysis (to determine the elements of C, O, F, Si and Ca). The following results were obtained when the above mentioned test results for FE-OBD (OBD mud tested FE) were compared to those of FE: The roughness and average height of surface decreased considerably (approximately -42% and -37%, respectively). Defects appeared on the surface. The swelling was negative and significant (nearly -15.7%). The surface was full of cracks. A considerable amount of fluorine was lost from the surface (Wt%: 32.0%). The following results were obtained when the before mentioned test results for BCNT/FE-OBD and CNT/FE-OBD compared to those of BCNT/FE and CNT/FE respectively: The changes in AFM results were minor. There were no defects on the surfaces. The swelling was low (approximately 5.7% and 4.1%, respectively). There were no cracks on the surfaces. Nanocomposites did not lose fluorine from the surface (Wt%: roughly 10.3% and 7.3%, respectively). Therefore, BCNT/FE and CNT/FE are resistant to OBD mud and can be used as sealing rubbers (for example o-rings) in OBD drilling for oil and gas. In contrast the original FE compound cannot be used.