# 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 10 ^{3} psi*

Elastic (Young's, Tensile) Modulus

13 *GPa* 1.8 *x 10 ^{6} psi*

Elongation at Break

31 *%*

Flexural Strength

62 *MPa* 9.0 *x 10 ^{3} psi*

Impact Strength: Notched Izod

14 *J/m* 0.26 *ft-lb/in*

Tensile Strength: Ultimate (UTS)

28 *MPa* 4.0 *x 10 ^{3} 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/cm ^{3}* 110

*lb/ft*

^{3}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 *10 ^{x} 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 *mm ^{2}/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