Phenol Formaldehyde (PF, Phenolic)
Phenolic is a thermoset plastic. It has the highest dielectric strength and a moderately low density among thermoset plastics. The graph bars on the material properties cards below compare phenolic to other thermoset plastics (top) and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.
Mechanical Properties
Elastic (Young's, Tensile) Modulus
3.8 GPa 0.55 x 106 psi
Elongation at Break
2.0 %
Tensile Strength: Ultimate (UTS)
48 MPa 7.0 x 103 psi
Thermal Properties
Glass Transition Temperature
170 °C 340 °F
Maximum Temperature: Autoignition
430 °C 810 °F
Maximum Temperature: Decomposition
260 °C 490 °F
Maximum Temperature: Mechanical
150 °C 300 °F
Specific Heat Capacity
1400 J/kg-K 0.33 BTU/lb-°F
Thermal Conductivity
0.25 W/m-K 0.14 BTU/h-ft-°F
Thermal Expansion
120 µm/m-K
Electrical Properties
Dielectric Constant (Relative Permittivity) At 1 MHz
7.5
Dielectric Strength (Breakdown Potential)
46 kV/mm 1.8 V/mil
Electrical Resistivity Order of Magnitude
11 10x Ω-m
Otherwise Unclassified Properties
Density
1.3 g/cm3 81 lb/ft3
Limiting Oxygen Index (LOI)
27 %
Common Calculations
Stiffness to Weight: Axial
1.6 points
Stiffness to Weight: Bending
40 points
Strength to Weight: Axial
10 points
Strength to Weight: Bending
23 points
Thermal Diffusivity
0.14 mm2/s
Thermal Shock Resistance
7.5 points
Followup Questions
Further Reading
ASTM C904: Standard Terminology Relating to Chemical-Resistant Nonmetallic Materials
ASTM D883: Standard Terminology Relating to Plastics
Thermosets: Structure, Properties and Applications, Qipeng Guo (editor), 2012
Modern Plastics Handbook, Charles A. Harper (editor), 1999
Plastics Materials, 7th ed., J. A. Brydson, 1999