Polystyrene Tribological Performance: Progress in the Understanding of Polymers Attrition during Chemical Engineering Processes

The issue of polymers films and particles friction, damage and attrition attracts both scientific and technological interest. In fact, polymers friction and attrition are of pivotal importance in many technological domains and applications such as powder technology, processes in fluidized beds, materials handling and transport processing (e.g., screw, pneumatic and hydraulic convey) and biopolymers and polymers processing. Moreover, polymer damage (e.g., attrition) has harmful effects on product quality, on environmental and health safety (source of toxic dust) and on the process reliability because of changes in particle properties such as particle shape and size distribution. The present contribution will focus on the attrition analysis induced by the rub of hemispherical polystyrene particles against smooth and functionalized silicon walls. Several experimental and structural factors affecting attrition of polymeric particles such as the velocity, the applied normal force, polymer molecular weights, and the wall surface energy are discussed. A homemade device was used to carry out a single slide of the polystyrene hemispherical (4 nm radius) particle onto different silicon walls. Atomic force microscopy (AFM) was used so as to analyze the attrition appearance induced by the polymer damage. Nano-friction experiments were also achieved by AFM in lateral mode in order to distinguish the effect of interfacial interactions at the nanometric scale.