Bismuth additives for silicon oils as a green alternative

MARIANA DENNEHY; CAMILA MÜLLER; WALTER TUCKART; ANDRÉS CIOLINO

Londres

Congreso; Polymer Congress 2018; 2018

Euroscicon meetings

Fluids formulations with good properties were developed by using an environmentally friendly additive. The performance of these formulations was studied at high and low contact pressure conditions on steel/steel and polymer/steel systems. Bismuth (III) sulfide powder (Bi2S3) was obtained by employing solvothermal synthesis procedures. An orthorrombic crystal lattice (DRX) and a high-purity product (FRX) was evidenced for the powder obtained, which was added to a vinyl-terminated silicone fluid to obtain different wt% mixtures. The tribological performance of the formulations prepared was studied from Reichert´s (steel/steel system) and block on ring (polymer/steel tests), according to standardized methodologies. The results obtained for these formulations were compared with those formulations prepared with commercial Bi2S3, commercial molybdenum (IV) sulfide (MoS2) and graphite. Lubricity properties increased when wt% of solvothermal Bi2S3 increased. The wear area decreased up to 90% according to Reichert´s tests. In addition, it was observed that solvothermal Bi2S3 shows a better tribological behavior when compared to commercial Bi2S3, MoS2, and graphite. These results show the possibility to replace lead (Pb) or molybdenum (Mo) derivatives in lubricants´ formulations by an environmentally friendly additive, suitable for extreme pressure (EP) formulations. Moreover, solvothermal Bi2S3 displayed an excellent performance in silicon oil formulations when compared to commercially used additives that opens a window for its use in lubricant´s formulations at high-temperatures.