Ultra-High Molecular Weight Polyethylene: Introduction & Properties
Ultra-high-molecular-weight polyethylene (UHMW-PE) is a semi-crystalline, thermoplastic polyethylene with a molecular mass in the range of over a million amu. Also known as high-modulus polyethylene, UHMW-PE has extremely long, non-branching, linear chains which transfer the load more effectively to the polymer backbone due to strong intermolecular interactions.
Fig 1: UHMWPE
This molecular structure results in a very tough material, with the highest impact strength of any thermoplastic presently made. UHMW-PEs are characterized by a low friction coefficient, high abrasion and wear resistance, and extremely high chemical resistance against concentrated acids, alkalis, and organic solvents. The superior physical properties of UHMW-PE have made it the material of choice for numerous industrial applications that require durability, low friction, and chemical resistance.
The properties UHMW-PE can be optimized using a proprietary catalyst and unique processing technology.
Managing the molecular weight and particle size distribution, during production, gives higher strength and abrasion resistance compared to general high-density polyethylene (HDPE). The abrasion resistance properties of UHMW-PE are even superior to carbon steel and brass.
UHMW-PE grades meet diverse industry needs due to the material's excellent chemical resistance, abrasion resistance, impact resistance and self-lubrication properties. UHMW-PEs are used in lithium-ion battery separators, industrial materials, and medical devices. It matches the essential characteristics of HDPE with added chemical resistance. The material has extremely low moisture absorption and is self-lubricating. They are odorless, tasteless, and nontoxic which makes it suitable for applications that require FDA compliant grades.
UHMW-PE can also be converted to a very fine polyethylene powder with an average particle diameter range of 10µm - 60µm. The spherical particles enhance the abrasion resistance and lubricity when used as an additive in coatings, rubber compounding and engineering plastics. This powdered form of UHMW-PE presents revolutionary solutions to the conventional fine powder additives market.
Another convertible form UHMW-PE is an injection and extrusion moldable technology. By injection molding, it allows more cost-effective method of manufacturing UHMW-PE parts in wide range of applications. This wear resistant material is used in a broad range of applications including automotive parts, electronics and building materials.