Polybutylene (polybutene*1, poly(*-butene), PB*1) is a polyolefin or saturated polymer with the chemical formula (C4H8)n. It should not be confused with polybutene, a low molecular weight oligomer with a different repeat unit.

Polybutylene is produced by polymerisation of *-butene using supported Ziegler-Natta catalysts. PB*1 is a high molecular weight, linear, isotactic, and semi-crystalline polymer. PB*1 combines typical characteristics of conventional polyolefins with certain properties of technical polymers.

PB*1, when applied as a pure or reinforced resin, can replace materials like metal, rubber and engineering polymers. It is also used synergistically as a blend element to modify the characteristics of other polyolefins like polypropylene and polyethylene. Because of its specific properties it is mainly used in pressure piping, flexible packaging, water heaters, compounding and hot melt adhesives.

Application areas

Piping systems

The main use of PB*1 is in flexible pressure piping systems for hot and cold drinking water distribution, pre-insulated district heating networks and surface heating and cooling systems. ISO ****6 defines the performance requirements of PB*1 piping systems.[8] The most striking features are weldability, temperature resistance, flexibility and high hydrostatic pressure resistance. The material can be classified PB **5 with a minimum required strength (MRS) of *2.5 MPa. Other features include low noise transmission, low linear thermal expansion, no corrosion and calcification.

PB*1 piping systems are no longer being sold in North America. The overall market share in Europe and Asia is rather small but PB*1 piping systems have shown a steady growth in recent years. In certain domestic markets, e.g. UK, Korea and Spain, PB*1 piping systems have a strong position.