Thermally Conductive Flexible Compounds with Boron Nitride CoolFX Powders

        




Styrenic TPE compounds can be formulated with a 65o Shore A hardness and different levels of additives, up to 30% (weight), to modify their thermal properties. As shown in the table below, using BN had the greatest effect, with a 50% improvement in the in- plane thermal conductivity of the compound. 

It is observed that the thermal conductivity is not improved in the cross-direction (through plane), indicating that the thermal conductivity is strongly affected by the orientation of the sample and the anisotropic structure of BN. On the contrary, it is possible to define an optimal composition (30% BN) to maximize thermal conductivity in the in-plane direction.

 Another important effect of BN is related to the flowability of the compounds. It can be observed that the melt flow of the samples formulated with BN present higher level values, indicating that the additive is acting as an internal lubricant of the material without affecting the rest of the material’s properties (for example the hardness).

    Note: Test data. Actual results may vary. 

Very favorable results in abrasion resistance of the compounds are also observed, even at high loading levels (30 wt% BN). 

Thermally conductive TPE compounds can be formulated for use in applications where heat transfer is an important factor, for instance in electronic housing sealing, soft electronic sensors, soft security sensors, etc. By using specific additives, the heat distribution of the different TPE compounds can be modified to reach the desired thermal and mechanical performance.

   

The use of BN from Momentive Performance Materials, in particular the fillers CoolFX Hybrid filler, can provide thermal conductivity performance and allow easily colourable compounds, as the powders are white. In this study, CoolFX 1022 Filler was evaluated, a proprietary powder developed to provide the best balance of thermal and mechanical properties and cost.

CoolFX hybrid fillers offer TPE formulators a very interesting tool for broadening the final applications of their materials and for reaching functional properties in demanding applications like flexible electronic housings, heating pads, multi-component pieces, thermal conductive sheets, and others. 

*CoolFX is a trademark of Momentive Performance Materials Inc. 

I.Alonso, Dynasol Elastómeros S.A.
Dr. C. Raman, Momentive Performance Materials Quartz Inc. 

For more details contact: Innovative Growth Enterprises, Ludhiana. Mob: 9910899409