Polymer Matrix Composites (PMCs) are one of the mostly used materials in aerospace and automotive applications due to their high mechanical strength and low weights. However, extremely low thermal conductivity of polymers leads to thermal bottlenecks in high temperature aerospace and automotive applications where dissipation of the heat is critical. The solutions proposed up to date concentrated on the usage of high thermal conductivity fillers such as graphene and CNTs. However, recurring studies demonstrated the inefficiency of 2D fillers in providing sufficient heat dissipation in the matrix, resulting in thermal failure. Thus, today, heat dissipation still stands out as one of the most important problem areas in aerospace and automotive applications.

My study proposes a new filler type, diamond nanoparticles, to be used in PMCs in order to reach thermal conductivity levels that was unattainable by CNTs, graphene, or h-BNs up to date. In order to lay the theoretical foundation of the study, a detailed analysis of heat conduction mechanisms in polymers and crystals at phonon level has been made, and phonon scattering mechanisms of diamonds has been compared with 2 dimensional fillers to explain how diamond nanoparticles are better thermal conductors when used as fillers in a polymer matrix.