Unlike thermoplastic polymers, when a thermosetting polymer is heated it does not begin to melt. Instead, they turn into a viscous rubbery phase over a short temperature range. This onset of change in the phase of the material is indicated by the glass transition temperature. Heating above this temperature could affect various properties of the polymer, such as mechanical strength, electrical properties and chemical resistance, among others.
The glass transition temperature (Tg) of an epoxy can be measure using various techniques, such as Differential Scanning Calorimetry (DSC), Dynamic Mechanical Analyzers (DMA) or Differential Thermomechanical Analyzers (DTA). Additionally, measuring the Heat Deflection Temperature (HDT) can also indicate the glass transition temperature (Tg) of an epoxy.
The Tg of an epoxy is affected not only by the choice of epoxy, curing agent and filler used, but also by the curing conditions. Epoxies demonstrate a wide range of Tg, from as low as 50°C to upwards of 250°C. In addition to improving its performance properties, adding heat while curing the epoxy helps improve its glass transition temperature (Tg).
Careful selection of the epoxy helps achieve the optimal performance over a wide temperature range in your application. Kohesi Bond’s technical experts can help you select the best epoxy suited for your application. Given below are the glass transition temperatures (Tg) of various Kohesi Bond epoxy systems.
|Product Name||Tg (°C)||Product Description|
|KB 1427 HT||220-230||One component, heat curing epoxy system suitable for bonding, sealing, coating, potting and encapsulation. It can be serviced at temperatures as high as 340°C.|
|KB 1427 HT-3||120||One component, snap curing epoxy system suitable for bonding, sealing, coating, potting and encapsulation. Additionally, it offers superior chemical resistance properties.|
|KB 1372-LP||128||Two component, heat curing epoxy system offering very long open time and chemical resistance.|
|KB 1372-AO||>150||Two component, heat curing epoxy system that offers superior thermal conductivity and high temperature resistance.|
|KB 1372-LO||>172||Two component epoxy system that offers phenomenal high temperature resistance. Additionally, it is capable of passing NASA standards for low outgassing (ASTM E-595).|