Properties of Atactic Polypropylene (PP)

Atactic polypropylene is a type of polypropylene polymer in which the methyl groups in the polymer chain are randomly arranged. Unlike isotactic polypropylene, where the methyl groups are consistently positioned on one side of the polymer chain, the random arrangement in atactic polypropylene results in an amorphous structure.

The following table provides a comprehensive list of polypropylene (atactic) properties in both SI and US customary/Imperial units at normal temperature and pressure (NTP).

Click on the icon to switch between Metric and Imperial units.

Table of Polypropylene (atactic) Properties
Physical Properties
Metric
CategoryThermoplastic
Density850 - 900 kg/m3
Water Absorption0.01 %wt/day
Mechanical PropertiesMetric
Ultimate Tensile Strength21.4 MPa
Young’s Modulus (E)0.69 - 1.52 GPa
Flexural Modulus0.9 GPa
Elongation at Break300%
Rockwell Hardness (R)95
Static Friction Coefficient (µ)0.1 - 0.3
Thermal PropertiesMetric
Melting Point176 °C
Thermal Conductivity0.12 W/m·K
Specific Heat Capacity (Cp)1960 J/kg·K
Coefficient of Thermal Expansion (αL)6.8×10-5 - 9.5×10-5 1/°C
Glass Transition Temperature (Tg)-18 °C
Electrical PropertiesMetric
Relative Permittivity (@1 MHz) (εr)2.2 - 2.3
Electrical Resistivity1016 Ω·cm
Dielectric Field Strength (Ed)200 - 260 kV/cm
Hazardous DataMetric
Flammability Rating (ANSI/UL 94)Combustible

Unless stated otherwise, all values are taken at room temperature (approximately 20°C or 68°F) and 1 atm pressure. (1 atm = 101,325 Pa)

Related Pages
References: 1) Cardarelli, François. Materials Handbook: A Concise Desktop Reference. Switzerland: Springer International Publishing, 2018. 2) CRC Handbook of Chemistry and Physics, 97th Edition. United Kingdom: CRC Press, 2016-2017. 3) A.M. Howatson, P.G. Lun, J.D. Todd, P.D. Engineering Tables and Data. United Kingdom: University of Oxford, Department of Engineering Science, 2009.