Materials / Compare
Rubber vs. Plastic UHMWPE
Compare Rubber vs. Plastic UHMWPE strength, stiffness, weight and thermal properties.
| Try it on a partA bracket to run stress or thermal on, free in your browser | Open in LessCAD | Open in LessCAD |
|---|---|---|
| Mechanical | ||
| Yield strength | not given (tensile used) | 20MPasourcetypical, tensile stress at yield ISO 527, 50 mm/min |
| Ultimate tensile strength | 23MPasourcetypical | 43MPasourcetypical, tensile stress at break ISO 527, 50 mm/min |
| Elongation at break | 830%sourcetypical | 465%sourcetypical, nominal elongation at break ISO 527 |
| Young's modulus (stiffness) | not sourced | 0.66GPasourcetypical, tensile modulus ISO 527, 1 mm/min |
| Density | 960kg/m³sourcetypical (specific gravity) | 930kg/m³sourcetypical |
| Strength to weight | 24kN·m/kg11% higher | 21.5kN·m/kg |
| Stiffness to weight | not sourced | 0.71MN·m/kg |
| Poisson's ratio | 0.5sourcegovernment (NBS J. Res. 68A, 1964): computed by NBS for peroxide-cured gum NR vulcanizate, 25 °C, infinitesimal deformation0.49 in the solver: the linear element locks as the ratio nears 0.5 (nearly incompressible). | not sourced |
| Shear modulus | not sourced | not sourced |
| Bulk modulus | not sourced | not sourced |
| Speed of sound | not sourced | 842m/s |
| Thermal | ||
| Thermal conductivity | 0.151W/m·Ksourcegovernment selected value (US Army Natick Laboratories TR 66-49-PR, 1966), soft vulcanized natural rubber, 25 °C | 0.4W/m·Ksourcetypical, unfilled (narrative value, generic Celanese UHMWPE) |
| Thermal expansion | not sourced | 200µm/m·Ksourcetypical, 20 to 100 °C (generic Celanese UHMWPE) |
| 100 mm part over a 50 °C swing | not sourced | 1,000µm growth |
| Specific heat | 1,881J/kg·Ksourcegovernment (NBS J. Res. 68A, Table 7; values observed for unvulcanized NR by Bekkedahl and Matheson), 25 °C | not sourced |
| Heats up and cools (diffusivity) | 0.0836mm²/s | not sourced |
| Thermal shock resistance | not sourced | not sourced |
| Melting point | not sourced | 130–138°CsourceDSC 10 K/min |
| Max service temperature | 70°Csourcecontinuous use operating range | 80°Csourcerecommended max constant operating temperature |
| Values for | Weir Minerals Linatex Premium rubber (95 % natural rubber), typical physical properties, spec sheet WMD0118/202305 | Celanese GUR 4120 (avg. molecular weight 4.7x10^6 g/mol), typical values on compression-molded specimens; CTE and thermal conductivity from Celanese's generic UHMWPE guide (grade not named) |
Every value links to the document that states it. "Not sourced" means no citable source states it (or only a specification minimum); figures computed from it are left out too.
Questions
Is Rubber stronger than Plastic UHMWPE?
Rubber is stronger: its tensile strength is 23 MPa against yield strength 20 MPa for Plastic UHMWPE (15%).
Which is lighter, Rubber or Plastic UHMWPE?
Plastic UHMWPE is lighter: 930 kg/m³ against 960 kg/m³ for Rubber.
Which is lighter for the same job, Rubber or Plastic UHMWPE?
For the same stiffness or strength: Rubber is lighter for a strong rod or tie, strong beam, strong panel or plate.
| Part that must be | Rubber | Plastic UHMWPE |
|---|---|---|
| Strong rod or tie | lighter | 11% heavier |
| Strong beam | lighter | 6% heavier |
| Strong panel or plate | lighter | 4% heavier |
For the same stiffness or strength, mass scales with density over stiffness (or strength) raised to a power set by how the part is loaded: 1 for a rod in tension, 1/2 for a beam in bending, 1/3 for a panel (the standard material-selection indices).
Which conducts heat better, Rubber or Plastic UHMWPE?
Plastic UHMWPE conducts heat better: 0.4 W/m·K against 0.151 W/m·K for Rubber.