Adhesives are a class of non-metallic materials that can be used to bond two surfaces together and resist separation (Figure 1). They can have secondary uses, for example in aiding the thermal management of the end product. Polymers make attractive adhesives due to their highly tunable chemistry and physical properties, their tunable phase and melt behavior, their chemical stability, thermal performance, and the fact that they may be synthesized in place (e.g. through thermoset or UV polymerization).
Of the polymer adhesives, epoxy resins represent a class of thermoset polymers that are very popular owing to the ability to polymerize them in place without the need for expensive auxiliary equipment or extensive safety precautions. Key performance attributes of epoxy resins include:
- Controllable curing
- High strength
- Tunable elasticity and hardness
- Good wettability
- Thin bond lines
- High thermal conductivity, particularly in electronics applications
- Tunable electrical conductivity
In a paper published in Composites Science and Technology, Lifei Chen et al explore the effect of filler loading on epoxy resin thermal conductivity using the Modified Transient Plane Source test method (Figure 2). Results of this work may be seen in Figure 3.
Using the MTPS method, the researchers were able to quickly and efficiently determine the effect of filler composition and loading on the thermal conductivity of their samples – and further to explore this relationship as a function of temperature.
In a paper published in the Journal of Applied Polymer Science, Guo et al study the effect of graphene powder loading and dispersion method on the effective thermal conductivity of epoxy resin composites. Results of their work are shown in Figure 4
Using the MTPS method, the researchers were able to determine the effect of filler loading and dispersion on the thermal conductivity of their samples – and further to explore this relationship as a function of mixing conditions.
These two case studies show how the Modified Transient Plane Source method enables fast and accurate determination of the key performance attribute of thermal adhesives and composites: that of the thermal conductivity.
Written by Sarah Ackermann, C-Therm Lab Manager & Application Specialist. To learn more, contact us at info@ctherm.com