Polybutene-1 Properties

In contrast to other competitive thermoplastics used in pressurised piping applications, performance modification of the material via compounding, cross-linking or copolymerisation is not necessary for PB-1 piping systems to fulfil the stringent performance standards applied to their use. Compared to other polyolefins, PB-1 has a higher level of resistance to strain under continually applied stress under heat over long periods of time.

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Material Properties

The following table illustrates the physical, mechanical and thermal properties of Polybutene-1. The values shown are typical mid-range figures and should not be considered as a specification - in fact, several different grades of Polybutene-1 are produced with properties tailored to satisfy different applicational requirements.


Material Properties Method Unit Akoalit
PB 4237
PB R 509
Physical Properties
Melt flow rate MRF 190°C/2.16 kg ISO 1133 dg/min 0.4 0.7
Density ISO 1183 g/cm3 0.925 0.925
Hardness Shore D ISO 868 - 60 60
Mechanical Properties
Tensile strength at yield ISO R 527 MPa 20 18
Tensile strength at break ISO R 527 MPa 35 38
Elongation at break ISO R 527 % 300 330
Flexural Elastic Modulus ISO R 173 MPa 450 330
Notched Impact Strength at 20°C ISO 180 kJ/m2 20 65
Notched Impact Strength at 0°C ISO 180 kJ/m2 7 25
Thermal Properties
Melting temperature range DSC (a) °C 127-129 124-126
Vicat Softening Temperature ISO 306 °C 120 117
Coefficient of linear thermal expansion ASTM D696 mm/m.K 0.13 0.13
Thermal conductivity (30-70°C) ASTM E1530 W/m.K 0.19 0.19
Glass transition temperature DMTA (b) °C -16 -18
Specific Characteristics
Wet abrasion
(Sand Slurry Test, 23°C, 100h)



(a) Differential Scanning Calorimetry
(b) Dynamic Mechanical Thermal Analysis


Polybutene is often referred to as Polybutene-1, Polybutylene, PB-1 or PB.

Polybutene is not sold by PBPSA members for use in pipe applications intended for use in North America, and those parties require their customers or distributors not to sell products made from Polybutene into pipe applications for North America.