BASIC FACTORS IN THE FORMATION AND STABILITY OF NON-SOAP GREASES FOR HIGH TEMPERATURE APPLICATIONS.
Abstract
The percent of the carbon black surface covered with hydrophilic sites was found to vary from 2.4 to 4.4 and was reduced to less than 1% by 1000 C pretreatment. The effect of these hydrophilic groups on the dispersion stability was found to be small in all cases, but the trend was toward a more stable system. The electrokinetic results of Carbolac 1 dispersed in heptanol indicate that the surface groups contribute to formation of the electrical double-layer and hence greater stability is brought about by the coulombic repulsion between particles. A study of the surface properties of Ammeline has revealed that Ammeline is unstable above 150 C. Nitrogen and water adsorption measurements have shown that this temperature treatment results in a decreased surface area. Furthermore, ammonia vapors were detectable after subjecting the Ammeline dispersions to the Shell Roll Test. The penetrometer results for the untreated and 1000 C pretreated Carbolac 1, XC-72 and Shawinigan carbon blacks dispersed in Silicone fluid QF-6-7024, both before and after the Shell Roll Test, are summarized. Gross changes in the degree of flocculation have been observed in the microscope and photographed for Carbolac 1 and low concentrations of XC-72. The results show that the SRT induces flocculation and the system was found to be reversible by again passing the dispersion through the three-roll mill. In all cases observed, a high penetrometer reading resulted in a flocculated system. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1967
- Accession Number
- AD0819754
Entities
People
- A. C. Zettlemoyer
- F. J. Micale
Organizations
- Lehigh University