EP: Epoxy resin

TS

Thermosets

General Properties

Short Name:

Name: 

EP

Epoxy resin


Epoxy resins (EP) undergo a polyaddition cross-linking reaction that does not release small molecules. The properties of the resin are strongly dependent on the structure, the degree of cross linking, type and amount of the reinforcement material and the processing procedure.

Structural Formula


Properties

Glass Transition Temperature50 to 200°C
Melting Temperature-
Melting Enthalpy-
Decomposition Temperature380 to 450°C
Young's Modulus3000 to 5000 MPa
Coefficient of Linear Thermal Expansion60 *10-6/K
Specific Heat Capacity1.67 to 2.10 J/(g*K)
Thermal Conductivity0.17 to 0.52 W/(m*K)
Density1.15 g/cm³
MorphologyThermoset
General propertiesGood toughness. Good adhesion on many substrates. Good chemical resistance. Low cure shrinkage
ProcessingCompression, spreading, injection processes such as RIM, VARI, RTM
ApplicationsBuilding industry (e.g., corrosion protection, sealings, floor coating). Boat building (construction adhesive). Electronics industry (circuit boards). Matrix for fiber-reinforced composites

NETZSCH Measurement

InstrumentDSC 204 F1 Phoenix®
Sample Mass13.22 mg
Isothermal Phase5 min
Heating/Colling Rates10 K/min
CrucibleAl, pierced lid
AtmosphereN2 (40 ml/min)

Evaluation

As an amorphous polymer, this epoxy resin exhibits a glass transition at 77°C (midpoint) with a specific heat capacity of 0.14 J/(g*K) in the 1st heating (blue) followed by an exothermal effect (peak temperature 174°C), due to post-curing of the resin. As a result of the post-curing, the glass transition temperature in the 2nd heating (red) is shifted to 88°C (midpoint). The step height remains nearly the same. Since no further exothermal effect occurs, it can be assumed that the epoxy resin was entirely cured during the 1st heating. Both the exothermal eff ect and the position (and shift) of the glass transition temperature to higher values can be interpreted as an evidence for the degree of curing of the material.