Global Advanced Technologies

We Provide Advanced Parylene Coating Solutions!

Polyurethane Coatings

Mil –Spec Type UR

Polyurethanes are very versatile coatings. They can withstand harsh chemicals and environmental conditions. Type UR coatings have a durable finish that provides a protective coating for printed circuit boards against water ingress, corrosion, and thermal shock.

Polyurethane coatings, as indicted in MIL-I-46058C, exhibit excellent electrical properties as well as acting as a good barrier against moisture, fungal growth, abrasive force, and chemicals/solvents.

Parts coated with Polyurethanes:

  • PCB- electronics
  • Motors
  • Transformers
  • Relays
  • Solenoids

Why Polyurethane (UR)?

  • Low cost compared to some other coatings
  • Application is by dip, brush or spray
  • Class F temperature rating (160°C / 320°F)
  • Excellent chemical resistance
  • Oil and moisture resistant
  • Very Good for coating circuit boards
  • UV indicator for quality inspection
  • Superior abrasion resistance
  • Excellent adhesion
  • Good flexibility
  • Can be thinned to desired viscosity

Typical Properties of Polyurethane coatings

Note: these can vary considerably from product to product and manufacturer to manufacturer

Hardness, Durometer Value
(ASTM d676-59T)
Specific Gravity 1.07
Tensile Strength, MPa (psi)
(ASTM D412-61T)
20.7 (3,000)
Elongation At Break, %
(ASTM D412-61T)
100% Modulus, MPa (psi)
(ASTM D412-61T)
2.8 (400)
Elongation At Break, %
(ASTM D412-61T)
Compression Set, %
Method B (ASTM D395)
Method A (ASTM D395)**
Resilience, %
Rebound (Bashore)
Impact Resistance,
Izod notched
J/m (
(ASTM D256)
24 Degrees C ( 75Degrees F)
-40 Degrees C (-40 Degrees F)
Solenoid Brittle Temp.,
Degrees C (Degrees F)
(ASTM D746-57)
Below -80
(Below -120)
Abrasion Index, NBS, %
(ASTM D1630, Nat'l Bureau of Standards Abrader)
Tear Strength Split, kN/m (pli)
(ASTM D470)
Dielectric Withstand 60Hz 1 mil thick 330-630

 Chemical Resistance of Polyurethane Coating

Note: these can vary considerably from product to product and manufacturer to manufacturer

Chemical Rating Chemical Rating
Acetic Acid, 20% B Ammonium Hydroxide Solutions A
ASTM Oil #1 (70°C/158°F) A ASTM Oil #3 (70°C/158°F) B
ASTM Reference Fuel A A ASTM Reference Fuel B (50°C/122°F) B
Barium Hydroxide Solutions A Borax Solutions A
Boris Acid Solutions A Butane A
Calcium Bisulfate Solutions A Calcium Chloride Solutions A
Calcium Hydroxide Solutions A Carbon Dioxide A
Carbon Monoxide A Castor Oil A
Copper Chloride Solutions A Copper Sulfate Solutions A
Cottonseed Oil A Cyclohexane A
DOWTHERM A B Ethylene Glycol B
Freon - 11 B Freon - 12 A
Freon - 113 A Fuel Oil B
Gasoline B Glue A
Glycerin A n-Hexane (50°C/122°F) B
Hydraulic Oils B Hydrochloric Acid, 20% B
Hydrogen A Isooctane (70°C/158°F) B
Isopropyl Ether B Linseed Oil B
Lubricating Oils B Magnesium Chloride Solutions A
Magnesium Hydroxide Solutions A Mercury A
Mineral Oil A Naphtha B
Naphthalene B Oleic Acid B
Palmitic Acid A Phosphoric Acid, 20%-70% A
Potassium Hydroxide Solutions B SAE #10 Oil (70°C/158°F) A
Seawater A Soap Solutions A
Sodium Hydroxide, 20% A Sodium Hydroxide, 46% B
Soybean Oil B Stearic Acid A A
Sulfuric Acid, 5-10% A Sulfuric Acid, 10-50% B-C
Tannic Acid, 10% A Tartaric Acid A
Tricresyl Phosphate B Trisodium Phosphate Solutions A
Tung Oil B Water (50°C/122°F) A