Abrasion resistance ultra high molecular weight polyethylen

Many polymer items are designed specifically to make contact with other materials. Where surface contact is concerned, two key properties are coefficient of friction and abrasion resistance. Polymers used in such applications include ultra high molecular weight polyethylene, polyacctal, fluorinated polymers, and natural and synthetic rubbers. Examples that we routinely come across include furniture upholstery, bushings and gears in office equipment, and bicycle tires. Industrial uses include the outer cover of electrical cables, and pipes that convey abrasive liquids such as slurries and powders. 

Polyolefins. Ultra-High-Molecular-Weight Polyethylene.TIus is easily made by conventional low-pressure coordination polymerization. Hercules Hi-fax 1900 has a molecular weight of 2.5-5.0 million. Its outstanding properties are low coefficient of friction (0.11) abrasion-resistance superior to nylon, polyurethane, and steel unbreakable in the Izod notched impact test and high resistance to most inorganic and many organic chemicals. 

Chen K.C., E.J. Ellis, and A. Crugnola. 1981. Effects of molding cycle on the molecular structure and abrasion resistance of ultra-high molecular weight polyethylene. ANTEC 81 39 270-272. 

Liu and co-workers [16] investigated the wear behaviour of ultra-high molecular weight polyethylene (UHMWPE) polymer. They concluded that the applied load is the main parameter and the wear resistance improvement of filler reinforced UHMWPE was attributed to the combination of hard particles, which prevent the formation of deep, wide and continuous furrows. Bijwe and co-workers [17] and Xu and Mellor [18] tested polyamide 6 (PA), polytetrafluoroethylene (PTFE) and their various composites in abrasive wear under dry and multi-pass conditions against SiC paper on a pin-on-disc tribometer. They concluded that the polymers without fillers had better abrasive wear resistance than their composites. 

Polyurethane elastomers containing ultra high molecular weight polyethylene (UHMWPE) as flllers show improved abrasion resistance. The UHMWPE is dispersed in the polyol in the formation of the filled polyurethanes. Commercial uses include gears, rollers, bushings, and mining screens. 

Base. Ultra-high-molecular-weight polyethylene is used because of its low coefficient of friction and abrasion resistance. 

Ultra-high molecular weight polyethylene (UHMWPE) has extremely high abrasion resistance when compared with other thermoplastics. It also has exceptional impact resistance, even at cryogenic temperatures, and is superior to stainless steel. Other advantages of UHMWPE include low moisture absorption, good electrical and thermal insulation, self-lubrication and chemical... 

Figure 9.16 Comparative abrasion resistance of various resins polyethylene is of ultra-high molecular weight type (Stein).

---