A study of the physical and tribological properties of biobased polymer–clay nanocomposites at different clay concentrations

Novel biobased nanocomposites have been prepared by the cationic copolymerization of conjugated low saturated soybean oil with styrene and divinylbenzene, and a reactive organomodified montmorillonite (VMMT) clay as reinforcing phase. Microscale tribological measurements were performed on samples with different concentration of VMMT (0%, 1% and 5%, w/w) using a ball-on-flat reciprocating microtribometer. Friction and wear behavior during dry sliding were evaluated using spherical (1.2 mm radius) steel probe as well as a conical (100 μm radius, 90° cone angle) diamond probe. Friction behavior was evaluated from single strokes at ramped normal loads, whereas wear experiments were evaluated from 10 to 1000 reciprocating cycles at fixed normal loads. Contact profilometry and scanning electron microscopy of wear tracks were used to elucidate deformation mechanisms in the various samples.