Evaluating Tackiness of Polymer ContainingLubricants by Open-Siphon Method:Experiments, Theory and Observations

摘要

Preparing and testing various lubricants withenhanced tackiness is in high demand forlubricant applications. However, noquantitative method has been currentlyproposed or used for tackiness evaluations.Present paper employs for this purpose thewell-known open-siphon method whereelastic liquids are vertically withdrawn out ofa jar by a vacuum connected capillary. Thesuction pulls a tacky liquid upwards out of thejar forming a free jet. More tacky fluids drawa longer jet in air than less tacky ones,whereas non-tacky fluids are not drawnupwards at all. In current experiments, theflow situation changed upon time, with thelevel of liquid in the jar slowly decreasing.Quantitative experimental time dependencesof the length (tackiness), shape of jets andflow rate were obtained for several values ofvacuum and for several lubricant liquids. Theexperimental liquids included very dilutesolutions of polyisobutylenes (PIB) of variousmolecular weights (MW) and concentrations,and a low concentration blend of a high MWPIB with a low MW non-tacky ethylenepropylene copolymers. For all the tested