The effects of temperature on the mechanical and tribological properties of progressing cavity pump NBR stator rubber

Abstract

This study used immersion and wear experiments to examine the swelling and tribological behaviors of nitrile-butadience (NBR) rubber with three acrylonitrile contents (N18, N26, and N41) in crude oil at varying temperatures. The results showed that in a crude oil medium with increasing temperatures, the N18 volume change rate (VCR) increased linearly, the N41 VCR decreased slightly, and N26 experienced a smaller change. As the temperature rose, the tensile strength and tensile fracture permanent deformation of NBR reduced. As the soaking temperature rose, the NBR wear loss increased and the friction coefficient decreased. When the rubber was soaked in crude oil, swelling gradually spread from the external portion to the internal portion. Due to its compact structure, NBR with high acrylonitrile content exhibited good heat resistance, swelling resistance, mechanical properties, and wearing capacity, but a poor resilience.

DOI: http://dx.doi.org/10.5755/j01.mech.22.4.16162