Influence of soap/polymer concentration ratio on the rheological properties of lithium lubricating greases modified with virgin LDPE

Formulation and processing of virgin and recycled polyolefin/oil blends for the development of lubricating greases

“…The values of the flow index are very low in all cases as a consequence of the typical yielding flow behavior of these materials. Similar results have been previously reported for modified lubricating greases [13][14][15][16]. Moreover, all the polyolefin/oil blends show Sisko's parameters and viscosity values higher than those previously found in traditional lithium lubricating greases, which may represent an important advantage from economic point of view.…”

“…It is well known that polymer melting point depression and broadening of the melting range occur when a low molecular weight material mixes uniformly with a crystalline polymer [26]. In this study, the melting point of the polymers appears slightly shifted to lower temperatures (see Table 2), as a consequence of the increased effective volume of polymers (polymer swelling) in the oil medium [13][14][15]. This displacement of the polymer melting point is more pronounced for PP/oil blends.…”

“…On the other hand, polyolefins, due to their ability for swelling and gel formation in organic media, might find a wide application in the industry as thickening agents or additives in lubricating grease formulations, since, it may reinforce the role of lubricants by modifying the film thickness in a lubricated contact [12]. In recent papers, we have shown that the viscoelastic and viscous behavior of lithium lubricating greases can be modified and improved by using different virgin and recycled polymers [13][14][15][16]. In this sense, different polymers were found to be effective additives in the modification of lithium lubricating grease rheology, acting as fillers in the soap entangled microstructure.…”

Rheological and Tribological Characterization of a New Acylated Chitosan–Based Biodegradable Lubricating Grease: A Comparative Study with Traditional Lithium and Calcium Greases

“…Conventionally, lubricating greases are defined as highly structured suspensions consisting of a thickener, normally fatty acid soaps of lithium, calcium, sodium, aluminum, or barium, dispersed in a mineral or synthetic oil (Martín-Alfonso, et al (1); Delgado,et al (2); National Lubricating Grease Institute (3)). Some additional components, called additives, are normally included in order to improve specific properties and functions.…”

Rheological characteristics of coal–water slurry using microwave pretreatment – A statistical approach

“…The rheological behavior of low-rank coal-water slurry from Lochiel, South Australia was reported as a function of solids concentration, particle size and size distribution [12]. The slurry behavior as well as rheology properties of various solutions have been reported in the literature [13] A new technique for the characterization of the rheology of mineral slurries into Newtonian and non-Newtonian flows was investigated [14]. A semi-empirical model was developed to predict slurry rheology from easily-measured slurry properties.…”