Monitoring Grease Production by Reaction Calorimetry and Thermoanalytical Methods as an Alternative to Dropping Point Determination

Abstract

The present research work concerns the thermodynamic study of lithium grease production by reaction calorimetry. In addition, several thermoanalytical techniques, such as differential scanning calorimetry and rheology, were employed to highlight grease thermal events. The results showed that the cooling rate mainly controls the crystallization of soap fibers and the formulation influences the reaction heat of saponification. The liquid fraction method (LFM) has been evaluated for both simple and complex lithium greases as a substitution technique to dropping point. For lithium grease, the results showed a very good correlation between LFM data and standard dropping point measurements. On the other hand, the LFM method was not applicable to complex lithium soap for dropping point determination by DSC, while it was shown that shear strain sweep led to a good correlation with dropping point values.

Properties of margarines prepared from soybean oil oleogels with mixtures of candelilla wax and beeswax

“…Correlation tests between dropping point and T p 2 showed no correlation with 3% wax margarines (coefficient of determination, R 2 = 0.014) and moderate inverse correlations with 5% and 7% wax margarines ( R 2 = 0.58 and 0.53, respectively). The dropping point is detected when the material slips out the hole of the samples cup and, sometimes, does not correlate with the melting temperature (Vincent et al., 2017). In their study with lithium greases, Vincent et al.…”

“…In their study with lithium greases, Vincent et al. (2017) found that the dropping point of grease was linked to the melting of a crystal network. Instead, the dropping point of margarine was correlated to T p 1 of margarines ( R 2 = 0.68, 0.92, and 0.89 for 3, 5, 7% wax, respectively).…”