Properties Resulting from Elevated versus Room Temperature Cure

4 Properties Resulting from Elevated versus Room Temperature Cure 

Postcuring at elevated temperatures after a room temperature cure is a common process in epoxy technology, and this can moderately increase the Tf in some systems.26 Such effects could be due to secondary reactions (irreversible) or to free volume effects (reversible). These effects could also be realized during the normal aging of the epoxy system in service. One should be careful, however, in assuming that a low-temperature cure followed by an elevated-temperature postcure (cure condition 1) will provide properties equivalent to only a high-temperature cure (cure condition 2). As explained in the previous section, the types 

TABLE 3.10 Thermal Properties of Various Epoxy Formulations25 

Property Method BF3 amine complex DTA MPD Aliphatic diamine 

Modified Vicat penetration, °C Coefficient of thermal expansion, in/in °C ASTM D 696 125 93 136 51 

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