Effect of Al2O3 and BN compounding on thermal and mechanical properties of PP composites

Using polypropylene (PP) as a matrix, boron nitride (BN), and alumina (Al2O3) as fillers, PP thermally conductive composites were prepared by melt blending, injection molding and hot press molding, and the effects of BN and Al2O3 compounding on the thermally conductive, crystalline and mechanical properties of the composites were investigated. It is found that with the shear force during processing and the volume flow force of PP matrix, BN and Al2O3 can be uniformly dispersed and oriented in PP matrix, and the two synergize with each other to form a three-dimensional thermal conductivity pathway, and The thermal conductivity of the composite reaches 0.54 W·m-1·K-1 when the volume shares of BN and Al2O3 is 9.09% and 8.10%, which is an increase of 157.14% compared with pure PP, and the crystallization peak temperature is the highest at this time. Meanwhile, through the LED lamp heat dissipation experiment, it was found that PP/BN-9.09/Al2O3-8.25 could effectively reduce the working temperature of LED, which has excellent practical value. In addition, the compounding of BN with a small amount of Al2O3 can greatly improve the mechanical properties of the composites.