Hypothesis: Polyamide-based blends, like most polymers, are thermally insulating materials, which restrict their application. An effective method to improve the thermal conductivity of polymers is manipulating the morphology and locating conductive fillers selectively at the polymer interfaces to induce heat conduction path way. In this regard, blending polyamide 6 with polyolefin elastomer and fillers such as aluminum nitride (AlN) and aluminum oxide (Al2O3) is an effective method to improve the thermal conductivity and mechanical properties Methods: The effect of 10% (by wt) aluminum nitride and aluminum oxide fillers and their mixture (with a ratio of 2:1) and different particle sizes on the induction of the structure of both continuous phases and the thermal conductivity of the polyamide-6 polyolefin elastomer mixture (80/20) in the molten state was investigated Findings: The results demonstrated that a stable co-continuous structure was formed by selective localization of fillers in the PA6/POE interphase. The xenon flash analysis results showed that the thermal conductivity of samples containing 10% (by wt) of AlN or Al2O3 reaches 2.22 and 1.29 W/m.K, respectively, which are 4.8 and 3 times higher than the thermal conductivity of pure sample. However, in the samples containing 10% (by wt) AlN/Al2O3 mixture with a mass ratio of 2:1, thermal conductivity reaches 3.34 W/m.K which is 7.23 times higher than that of pure sample It can also be pointed to the fact that the gap of large size particle (Al2O3) is filled by the small size filler (AlN), therefore, the contact surface area of irregular AlN particles and Al2O3 spherical particles increases, which in turn has a synergistic effect on improving the thermal conductivity of the composite. It can be confidently claimed that this is a promising approach for the design of thermally conductive composites with favorable properties, light weight, and low cost.
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