Correlations between two methods for cloud point and pour point determination of biobased materials

Authors: Bantchev, Grigor

Submitted to: Society of Tribologists and Lubrication Engineers
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2023
Publication Date: 5/21/2023
Citation: Bantchev, G.B. 2023. Correlations between two methods for cloud point and pour point determination of biobased materials [abstract]. Society of Tribologists and Lubrication Engineers Annual Meeting & Exhibition.

Interpretive Summary:

Technical Abstract: The ASTM methods D97 and D2500 are well accepted and widely used for measuring the pour points (PP) and cloud points (CP) of lubricants. However, these methods require relatively large volumes (50 ml) of sample which can be problematic when screening a large number of lubricants during the early stages of lubricant candidate selection. The newer ASTM methods D5949 (PP) and D5773 (CP) require much smaller samples (microliters) and are easier to perform. However, they are not currently as widely accepted. In the current report, the CP and PP of ~40 biobased materials (estolides, iso-estolides, their esters and vegetable oils) were measured by the two sets of ASTM methods and the results correlated. The correlations between the two methods were poor: r2=0.68 for PP and r2=0.60 for the CP; however, they could be improved by a correction equation using the viscosity of the samples.