Client request
The client reports the formation of a whitish solid residue on an NBR rubber gasket after four months of field use. The objective is to determine the cause/and nature of this formation: is it an external residue or a material-related issue?
The solution proposed by Plastanalisi
The Plastanalisi laboratory decided to proceed with the analysis of the powder by first collecting an appropriate sample and then conducting FT-IR spectroscopic analysis with the ATR technique, which was further complemented by the SEM-EDS analysis.
Analysis results
The ATR-FT-IR analysis of the sampled powder allows identifying an organic compound commonly used as a plasticizer in rubber formulations.
The analysis confirmed the presence of a stearate-based compound, specifically Zinc Stearate.
This substance is an integral component of the NBR rubber, and its surface appearance is likely due to the migration of the plasticizer from the material to the surface over time.
The SEM-EDS elemental microanalysis of the powder confirmed the presence of zinc (Zn), supporting the FT-IR data (regarding zinc stearate.). The SEM-EDS analysis also detected the presence of Sodium (Na), chlorine (Cl) and potassium (K). These substances are not directly inherent to the NBR rubber but probably originate from the working environment.
