The tribological properties of derivatives of the polyalkoxyglycol esters of dithiophosphoric acid were tested using four‐ball and ball‐on‐disc machines. Polybutoxyglycol dithiophosphoric acid derivatives were found to be effective load‐carrying additives in mineral base oil. Four‐ball and ball‐on‐disc data of some of these additives showed them to have very good antiwear/extreme‐pressure and antifriction properties. These properties were dependent upon the additive's chemical nature, concentration, sliding speed, and load. The presence of polybutoxy groups decreased the concentration of phosphorus in the additive in comparison to zinc dialkyldithiophosphates.

This paper presents micro and nanofriction studies on thin silica/aminosilica-triazine hybrid composite coatings on silicon substrate. The silica/aminosilica coatings were made on silicon using the dip-coating method and then modified by alkoxy-and aryloxy-triazine derivatives. Formation of hybrid coatings permits a greater flexibility of their resulting properties. Microfriction tests were carried out with a sliding ceramic ball (load range of 10-80 mN) on the composite flat surface, using a tribometer ball-onsample system. Sliding speed was 25 mm/min at room temperature. Nanofriction was measured using the Friction Force Microscopy. It is shown that surface modification of silica/aminosilica layers by triazine derivatives, to form inorganic-organic hybrid coatings, improves friction properties. All tested triazine derivatives, particularly long alkoxy-substituted s-triazines, cause a decrease in the friction coefficients in microfriction tests, in comparison to a non-modified silica/aminosilica thin film. The same effect was also observed for some tested triazine derivatives at nanofriction measurements.

Synthesis of organic/inorganic hybrid materials is an area of growing interest as advantageous properties of disparate components can be combined into singular materials. In this study, nanosized silica gel hybrids were obtained by reaction between silanol groups of silica and 2,4-dichloro-6-methoxy-1,3,5-triazine (DCMT), which then reacted with p-phenylenediamine. Acylation of amine by 10-undecanoic acid, N-Fmoc-Lys(Boc)OH, and N-Boc-Ser(OH)OH was the final step. Friction performance of silicatriazine hybrids, evaluated with a microtribometer, can be ranked in the following order: 10-undecanoic acid >N-FmocLys(Boc)OH>p-phenylenediamine>N-Boc-Ser(OH)OH. It is inferred that all the hybrids are effective in reducing friction, in comparison to pure silica materials. The rearrangement of silica-triazine hybrid included the 10-undecanoic acid, induced by UV exposure, also confirmed further improvement of friction performance. This approach can be successfully applied to preparation of other ORMOSIL hybrids.