Polymer
PNR
Properties, grades, machining, finishes and uses — values shown for the SA40 condition.
PNR (Norsorex) is a very high molecular weight polynorbornene cycloolefin elastomer supplied in raw form that absorbs large volumes of plasticizer or oil, allowing compounds from roughly Shore A 15 to 60.
Reference datasheet — PNR is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
What is PNR?
PNR (Norsorex) is a very high molecular weight polynorbornene cycloolefin elastomer supplied in raw form that absorbs large volumes of plasticizer or oil, allowing compounds from roughly Shore A 15 to 60. Oil-extended stock reaches about 8 MPa tensile strength, 400 % elongation and an elastic modulus near 0.003 GPa, with service to 90 °C. It is specified for high-hysteresis vibration damping and sound insulation, and as an oil-sorbent or damping masterbatch. Strength, heat and weather resistance are low and compounds are tacky with a risk of oil bleed; butyl or EPDM is the alternative when softness can be traded for durability. PNR has a density of 1 g/cm³ (0.0361 lb/in³), lighter than 72% of polymer grades. Its glass-transition temperature is -25°C (-13 °F). PNR has a tensile strength of 8 MPa (1.16 ksi), weaker than 81% of polymer grades. Elongation at break is 400% and the elastic modulus is 0 GPa (4.35×10⁻⁴ Msi).
What is PNR used for?
- vibration damping mounts
- sound insulation
- oil-extended soft compounds
Advantages
- Ductile — tolerates forming and impact — 400%, better than 86% of polymer grades
- Forms and bends easily — 85/100, better than 82% of polymer grades
Limitations
- Difficult to machine — 20/100, worse than 97% of polymer grades
- Low stiffness — 0 GPa (4.35×10⁻⁴ Msi), worse than 93% of polymer grades
- High mold shrinkage — 2%, worse than 81% of polymer grades
PNR properties
Typical room-temperature values for PNR-SA40 (default engineering compound: best compromise of damping, strength and processability for molded damping parts), compiled from standards, handbooks and producer data. Each bar shows where the value sits among the polymer grades in FabDigit's library — further right is higher. Other conditions have their own pages: see tempers.
Physical3
PNR has a density of 1 g/cm³ (0.0361 lb/in³), lighter than 72% of polymer grades. Its glass-transition temperature is -25°C (-13 °F).
Mechanical8
PNR has a tensile strength of 8 MPa (1.16 ksi), weaker than 81% of polymer grades. Elongation at break is 400% and the elastic modulus is 0 GPa (4.35×10⁻⁴ Msi).
Thermal8
PNR is rated for continuous service to 90°C (194 °F). It conducts heat at 0.2 W/m·K (0.116 BTU/hr·ft·°F), worse than 56% of polymer grades. Thermal expansion is 220 µm/m·K (122.2 µin/in·°F).
Electrical4
PNR is an electrical insulator with a dielectric strength of 18 kV/mm (457.2 V/mil) and a resistivity of 1×10¹¹ Ω·m.
Chemical & Environmental2
UV resistance is fair.
Sustainability4
Producing a kilogram of PNR takes about 105 MJ of energy and emits 4.5 kg of CO₂ — more than 54% of polymer grades. Typical recycled content is 0%.
Manufacturability4
PNR's machinability is poor (20/100, worse than 97% of polymer grades); formability excellent (85/100).
Common Calculations4
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
PNR grades and fills
PNR is supplied in 9 conditions, each with its own property set. Open one for its full datasheet. SA40 is what FabDigit quotes unless the drawing says otherwise.
- SA40DefaultDefault engineering compound: best compromise of damping, strength and processability for molded damping parts.8 MPa tensile
- SA60Choose when higher load capacity, abrasion and grip are needed (rolls, non-slip pads) and damping can be traded off.12 MPa tensile
- SA15Use for very soft seat/instrument damping pads and low-frequency isolators where deflection matters more than strength.4 MPa tensile
6 further conditions are listed below with a summary only.
| Condition | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
SA40Default general-purpose oil-extended PNR vulcanizate | Default engineering compound: best compromise of damping, strength and processability for molded damping parts. | — | 8 | 400 | 40 Shore A | — |
raw polynorbornene powder (Norsorex APX, uncompounded) | Pick when buying the base polymer powder for your own oil-extended compound or as a damping/sorbent additive. | — | — | — | 90 Shore A | — |
ultra-soft, highly oil-extended damping compound | Use for very soft seat/instrument damping pads and low-frequency isolators where deflection matters more than strength. | — | 4 | 600 | 15 Shore A | — |
soft high-damping vulcanizate | Balanced softness and tear strength for anti-vibration mounts and acoustic sheet. | — | 6 | 500 | 30 Shore A | — |
low-oil, carbon-black reinforced compound | Choose when higher load capacity, abrasion and grip are needed (rolls, non-slip pads) and damping can be traded off. | — | 12 | 300 | 60 Shore A | — |
maximized tan δ / low rebound | Specify for vibration and structure-borne noise control where loss factor across a broad temperature band is the design driver. | — | 6 | 450 | 35 Shore A | — |
Masterbatch / blend modifier for NR, SBR, EPDM, NBR | Use 5–30 phr of PNR powder in a conventional rubber to raise damping, grip and oil-carrying capacity. | — | 12 | 400 | 55 Shore A | — |
hydrocarbon spill absorption | Raw or lightly crosslinked powder/mat used to gel and recover oil spills; absorbs many times its own weight of hydrocarbons. | — | — | — | 20 Shore A | — |
flame-retardant compound (halogen-free or ATH filled) | Choose for rail, building and electrical damping parts needing UL 94 V-0 / low smoke behaviour. | — | 6 | 250 | 55 Shore A | — |
Working with PNR
Is PNR easy to machine?
Too soft and tacky for conventional cutting — use water-jet, die cutting or cryogenic trimming; freeze before grinding.
Can PNR be welded?
Not weldable; join by co-vulcanization, adhesive bonding (cyanoacrylate/polyurethane after surface priming) or mechanical capture.
Can PNR be formed, bent or molded?
Mix on cold two-roll mill or internal mixer at low temperature (oil is absorbed rapidly), then compression/transfer/injection mold and cure 5–20 min at 150–170 °C with sulfur or peroxide.
Strength versus weight in the polymer family
Yield strength against density for every polymer grade FabDigit runs. PNR is highlighted; hover a dot for its name, or open the interactive family chart.
PNR chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| extender oil (naphthenic/paraffinic or ephr on polymer; sets hardness and Tg of the compound | 50 – 500 | 200 |
| carbon black / mineral fillerphr, reinforcement | 0 – 100 | 30 |
| sulfur or peroxide cure system + activatphr | 2 – 8 | 5 |
| antioxidant / antiozonantphr | 1 – 3 | 2 |
| polynorbornene (bicyclo[2.2.1]hept-2-enebase polymer, Mw typically >2×10^6 g/mol, ~90% trans ring-opened units | balance | — |
What surface finishes work on PNR?
No plating or painting; surface can be textured in the mold, dusted with talc/silicone to kill tack, or coated with a flock/lacquer for abrasion and oil-bleed control.
Equivalent designations
Standards and trade names that resolve to PNR in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Trade names
- Norsorex
- Also called
How much does PNR cost?
PNR is a high-cost polymer ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
PNR — frequently asked
What is PNR used for?
PNR is typically used for vibration damping mounts, sound insulation and oil-extended soft compounds. In short: softest oil-extended elastomer; high-hysteresis damping compounds; shore A 15 achievable.
What is the tensile strength of PNR?
PNR has a typical tensile strength of 8 MPa (1.16 ksi) — weaker than 81% of polymer grades. Strength varies by condition: see the 9 listed tempers.
Is PNR easy to machine?
Not especially — machinability is rated poor (20/100, worse than 97% of polymer grades). Too soft and tacky for conventional cutting — use water-jet, die cutting or cryogenic trimming; freeze before grinding.
Can PNR be welded?
Not weldable; join by co-vulcanization, adhesive bonding (cyanoacrylate/polyurethane after surface priming) or mechanical capture.
What surface finishes work on PNR?
No plating or painting; surface can be textured in the mold, dusted with talc/silicone to kill tack, or coated with a flock/lacquer for abrasion and oil-bleed control.
Can PNR be formed, bent or molded?
Mix on cold two-roll mill or internal mixer at low temperature (oil is absorbed rapidly), then compression/transfer/injection mold and cure 5–20 min at 150–170 °C with sulfur or peroxide.
What is the maximum service temperature of PNR?
PNR is rated for continuous use to about 90°C (194 °F), and briefly to 120°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does PNR cost?
PNR is a high-cost polymer ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- Norsorex APX polynorbornene technical data — Astrotech Advanced Elastomer Products / Zeon (2020)
- Rubber Technology Handbook — specialty elastomers chapter — Hanser (2012)
- Polymer Handbook (Tg and density of polynorbornene) — Wiley (2005)
- ASTM D2000 — classification system for rubber products — ASTM (2018)
- Norsorex (2025)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.