TRIBOLOGY OF POLYMERS AND POLYMER-BASED COMPOSITES

While attention of academia and industry on materia ls properties is largely focused on mechanics, wear causes losses in industry at least not smaller tha n fracture caused by mechanical deformation. We discuss the importance of tribology for polymer- based materials (PBMs). Traditional tribology developed originally for metals cannot be applied t o PBMs for at least two reasons. First, PBMs are viscoelastic and their properties depend on time ‐ in contrast to metals and ceramics. Second, external liquid lubricants, which work well for other cl asses of materials, are easily absorbed by PBMs; swelling is the result. We and others are developin g tribology of PBMs taking into account among others: viscoelasticity, materials brittleness defi ned in 2006 and connections of brittleness to recov ery in sliding wear determination, relation of fric tion and scratch resistance to surface tension, and effects of magnetic fields on polymer tribology. Tr aditional experimental methods of wear determination based on the amount of debris formed are not well usable for PBMs since often there is no debris - while there is significant material displace ment (top ridge formation, densification). More appropriate testing procedures are discussed. Results of molecular dynamics computer simulations of scratching of polymers are discussed also. Further, we discuss methods of enhancing resistance of PBMs to scratching and wear. These methods include modifying surface tension, formation of microhybrids, formation of nanohybrids, irradiation, as well as already mentioned application of magnetic fields. On the basis of the totality of exper imental and simulation results as well as concepts and models developed, some recommendations for dealing with tribology of PBMs ‐ in instructional as well as industrial and research setting - are ma de.