Solubility and Compatibility Analysis of Nitrile Butadiene Rubber (NBR) of Varying ACN Content in Selected Solvents.

The solubility and compatibility of nitrile butadiene rubber (NBR) with varying acrylonitrile (ACN) content were investigated in a series of solvents with different polarity characteristics. NBR grades containing 18%, 28.3%, 33.15%, and 38.15% ACN were studied in ethyl acetate, acetone, methyl ethyl ketone (MEK), hexane, and dimethyl sulfoxide (DMSO). Solubility tests revealed that NBR was soluble in ethyl acetate, acetone, and MEK, while remaining insoluble in hexane and DMSO. Differential scanning calorimetry (DSC) was employed to evaluate glass transition temperature (Tg), showing a strong dependence on both ACN content and solvent type. Results demonstrated that higher ACN content increases polarity-driven interactions, shifting Tg accordingly, with MEK imparting the strongest plasticization effect. The study provides a systematic framework for understanding solvent–NBR interactions, which is critical for adhesives, coatings, and rubber compounding industries.