Polybutene-1 is a member of the polyolefin family of thermoplastic materials which also includes polyethylene and polypropylene.

Polybutene exists in two isomeric forms depending on where the carbon double bond is positioned in the monomer molecule. If it is between the first and second carbon atoms in a linear molecule (Butene-1), then the chemically accurate name of the resulting polymer is 'Polybutene-1' (PB-1). If it is a branched monomer molecule then the resulting polymer is called Polyisobutylene (PIB).

The polymer we are concerned with is Polybutene-1. In the past this polymer has been referred to as polybutylene, PB, PB-1 and polybutene, as well as its chemically correct name, Polybutene-1.

As a matter of interest, polyisobutylene, produced from the alternative isomeric monomer form, is a non-crystalline, low-viscosity polymer used as a viscosity modifier in the oil products business, and also in the manufacture of chewing gum.

In chemical structure Polybutene-1 differs from polyethylene and polypropylene only by the number of carbon atoms in the monomer molecule:

It is manufactured utilising Zeigler-Natta type catalysts which produce a highly isotactic thermoplastic. A unique crystalline structure, combined with carefully controlled molecular parameters give Polybutene-1 a combination of properties ideally suited to end-use applications requiring both high strength and flexibility at temperatures up to 100°C.

Polybutene-1 can be processed via injection moulding or extrusion into a range of applicational products. Its primary use however has been in the manufacture of pipes for hot and cold pressurised water systems. In its most simple homopolymer form the balance of properties of Polybutene-1 make it the technically preferred material for the production of pressurised hot and cold water pipes. In contrast to competitive thermoplastics used in these applications, performance modification via compounding, cross-linking or copolymerisation is not necessary for Polybutene-1 pipes to fulfil the stringent performance standards applied to their use.

As an essentially 'pure' highly isotactic homopolymer, Polybutene-1 is more easily specified to consistently achieve quality performance.

In comparison with other polyolefin materials, Polybutene-1 has a higher level of resistance to strain under continually applied stress over long periods of time. This is known as creep behaviour and the graph illustrates the increasingly superior performance of Polybutene-1 - at times in excess of 100 hours.

In addition to its superior mechanical and thermal properties, Polybutene-1 provides a high level of resistance to chemical attack and also meets a level of flammability resistance which satisfies most applicational demands.