A thermally conducting polymer composite system

Abstract

The purpose of this study is to improve thermal conductivity and mechanical properties of Polypropylene (PP) of HD 91SCF grade and PP/ POLYAMIDE Durethan T40 50:50 blend matrices by adding fillers. Graphene (Gr) and Boron nitride (BN) were used for enhancing the thermal conductivity of polymers. PP/BN, PP/ Graphene, PP/PA/BN and PP/PA/ Graphene composites were produced by using mini-extruder. Compatibilizer of PP-g-MA was blended with PP to make a more stable and better blended phase morphology by creating interactions between polymer and filler that enhances the mechanical properties of the blend. Results have proven that in the absence of the compatibilizer, the crystallinity of PP nanocomposites increases with increasing graphene content. In the presence of the compatibilizer, the % of crystallinity of nanocomposites increases significantly at a lower graphene content (3wt. %). Moreover, in the presence of the compatibilizer and in the PP+PA blend, the addition of graphene and BN increase the thermal stability and char yield of composites. In terms of the mechanical properties, the tensile strength and elongation at break decrease with the addition of graphene content to the PP, PP+PP-g- MA and PP+PA blend. The BN particles are stiffer than that of polymer matrix, hence the addition of BN particles increases the modules of the composites. In terms of the electrical properties, the addition of graphene reduces the surface resistivity of PP and PP blends. However, BN particle develops the electrical insulating property of the pure PP with increase in wt. % of BN particle. In terms of the thermal conductivity, PP+PP-g-MA+10wt. % BN has highest value of thermal conductivity among the BN composites. In the case of graphene filled PP nanocomposites, 5wt. % graphene filled PP+PP-g-MA composites shows highest thermal conductivity compared to the other composites and polymer matrices. In many applications which require high thermal conductivity and in areas where good heat dissipation and low weight are required, these polymer composites can be used.

Date of Award	2016
Original language	American English
Supervisor	Vikas Mittal (Supervisor)