Harmonization Code : 3907.30.00.90 |   Polyacetals, other polyethers and epoxide resins, in primary forms; polycarbonates, alkyd resins, polyallyl esters and other polyesters, in primary forms : Epoxide resins : Other
Main features
  • Two components
  • Potting component
  • Room temperature cure

Product Description

LOCTITE STYCAST U 2500 is a polyurethane encapsulant designed for transformer, PCB's and other insulation applications. It allows for complete impregnation when used either on small slightly wound coils or large castings.

LOCTITE STYCAST U 2500 exhibits excellent wettability, flexibility and can cure in room temperature. Its operating temperature is between -40°C to 125°C.


Cure Schedule

  • 24 hours @ 25°C or
  • 4 hours @ 60°C

Complete cure at room temperature will be obtained after 2 to 3days.

Product Family
1Kg Quart Kit 500cc Bottle

Catalog Product

Unlike other products we offer, the products listed on this page cannot currently be ordered directly from the website.

Technical Specifications

Physical Properties
Viscosity is a measurement of a fluid’s resistance to flow.

Viscosity is commonly measured in centiPoise (cP). One cP is defined as
the viscosity of water and all other viscosities are derived from this base. MPa is another common unit with a 1:1 conversion to cP.

A product like honey would have a much higher viscosity -around 10,000 cPs-
compared to water. As a result, honey would flow much slower out of a tipped glass than
water would.

The viscosity of a material can be decreased with an increase in temperature in
order to better suit an application
12,500 mPa.s
Chemical Properties
Moisture absorption 0.75 %
Mechanical Properties
Elongation is the process of lengthening something.

It is a percentage that measures the initial, unstressed, length compared to the length of the material right before it breaks.

It is commonly referred to as Ultimate Elongation or Tensile Elongation at break.
82 %
Thermal Properties
Coefficient of Thermal Expansion (CTE)
Coefficient of Thermal Expansion (CTE)
CTE (Coefficient of thermal expansion) is a material property that is indicative of the extent to which a material expands with a change in temperature. This can be a change in length, area or volume, depending on the material.

Knowing the CTE of the layers is helpful in analyzing stresses that might occur when a
system consists of an adhesive plus some other solid component.
Coefficient of Thermal Expansion (CTE), α1
Coefficient of Thermal Expansion (CTE), α1
CTE α1 (alpha 1) is the slope of the Coefficient of thermal expansion in a temperature range below the Glass transition temperature (Tg).

It explains how much a material will expand until it reaches Tg.
155 ppm/°C
Glass Transition Temperature (Tg)
Glass Transition Temperature (Tg)
The glass transition temperature for organic adhesives is a temperature region where the polymers change from glassy and brittle to soft and rubbery. Increasing the temperature further continues the softening process as the viscosity drops too. Temperatures between the glass transition temperature and below the decomposition point of the adhesive are the best region for bonding.

The glass-transition temperature Tg of a material characterizes the range of temperatures over which this glass transition occurs.
-53 °C
Thermal Conductivity
Thermal Conductivity
Thermal conductivity describes the ability of a material to conduct heat. It is required by power packages in order to dissipate heat and maintain stable electrical performance.

Thermal conductivity units are [W/(m K)] in the SI system and [Btu/(hr ft °F)] in the Imperial system.
0.5 W/m.K

Additional Information

Cure Schedule


  • 16 to 24 hours @ 25°C
  • 4 to 6 hours @ 45°C
  • 1 to 2 hours @ 65°C


  • 8 to 16 hours @ 80°C
  • 2 to 4 hours @ 100°C
  • 30 to 60 minutes @ 120°C


  • 16 to 24 hours @ 25°C
  • 4 to 6 hours @ 45°C
  • 2 to 4 hours @ 65°C


  • 8 to 16 hours @ 25°C
  • 4 to 6 hours @ 45°C
  • 2 hours @ 65°C


  • 4 hours @ 120°C