We have data below that says the oil doesn't shear. TorrLube® oils have thicker films and carry higher loads than other types of lubricants. They are excellent EHD lubricants because they thicken and gain viscosity when under load.
Although TorrLube® oils are polymeric in nature, they do not break down when subjected to high rates of shear. Irradiation at 10 kilocycles in a sonic shear tester for one hour resulted in viscosity changes of less than 0.5 percent. Braycote is a PFPE based on the linear Fomblin Z oils and they don't carry load as well and can't go as high in temperature as branched TorrLube® PFPE's can go to. Some chemical stability data below. TorrLube® perfluoropolyethers do not contain acetyl linkage groups (-O-CF2-O-), which are significantly more susceptible to chemical attack. The absence of -O-CF2-O- linkages throughout the entire polymer chain is a fundamental feature of TorrLube®, and it is this feature that gives TorrLube® superior stability when attacked by aggressive chemicals, such as the Lewis acid aluminum chloride. The pendant trifluoromethyl group provides some shielding and further enhances the stability of the ether oxygen links of TorrLube® oil.
The combination of Lewis acids and perfluoralkyl ethers results in the formation of lower molecular weight and more volatile fragments by the depolymerization of the original oil molecule. With TorrLube® oils, this depolymerization occurs more slowly and by a different mechanism than fluids with different molecular structures. The threshold temperatures for the reaction of some commercial fluids in the presence of the Lewis acid aluminum chloride, as measured in a differential scanning calorimeter (DSC), are compared in Table 11. "
