Diallyl Phthalate (DAP)
DAP is a thermoset plastic. It has the lowest tensile strength among thermoset plastics. In addition, it has the lowest mechanical heat stability and a fairly high dielectric strength. The graph bars on the material properties cards below compare DAP 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
Compressive (Crushing) Strength
150 MPa 22 x 103 psi
Elastic (Young's, Tensile) Modulus
13 GPa 1.8 x 106 psi
Elongation at Break
31 %
Flexural Strength
62 MPa 9.0 x 103 psi
Impact Strength: Notched Izod
14 J/m 0.26 ft-lb/in
Tensile Strength: Ultimate (UTS)
28 MPa 4.0 x 103 psi
Thermal Properties
Glass Transition Temperature
150 °C 300 °F
Heat Deflection Temperature At 1.82 MPa (264 psi)
160 °C 310 °F
Specific Heat Capacity
1450 J/kg-K 0.35 BTU/lb-°F
Thermal Conductivity
0.6 W/m-K 0.35 BTU/h-ft-°F
Thermal Expansion
25 µm/m-K
Other Material Properties
Density
1.7 g/cm3 110 lb/ft3
Dielectric Constant (Relative Permittivity) At 1 Hz
5.2
Dielectric Strength (Breakdown Potential)
40 kV/mm 1.6 V/mil
Electrical Resistivity Order of Magnitude
13 10x Ω-m
Common Calculations
Stiffness to Weight: Axial
4.1 points
Stiffness to Weight: Bending
46 points
Strength to Weight: Axial
4.5 points
Strength to Weight: Bending
12 points
Thermal Diffusivity
0.24 mm2/s
Thermal Shock Resistance
6.3 points
Followup Questions
Further Reading
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