• adhesion
• aptes
• automotive
• boron
• conductivity
• nitride
• polyamide
• thermal

The aim of this thesis is to develop a composite material with a bio-based matrix and high thermal conductivity, suitable for under-the-hood applications in the automotive industry.
To achieve this, the interphase adhesion between polyamide 11 and hexagonal boron nitride (h-BN) particles was enhanced through a surface modification process, involving the grafting of (3-Aminopropyl)triethoxysilane (APTES).
The study was divided in three phases. In the first phase, the optimal filler content to enhance the thermal conductivity of the composite was determined. Composites containing 10, 20, and 30 wt.% of h-BN filler, were extruded and subjected to mechanical and thermal characterizations (MFI, DSC, tensile and flexural tests, DMTA, Shore D and thermal conductivity tests). The results revealed an increasing trend in thermal conductivity with higher filler content.
In the second phase, the surface modification of h-BN particles was performed using APTES. The effectiveness of this modification was assessed using FT-IR, TGA, EDS and SEM.
In the final phase, a composite with 30 wt.% of APTES-modified h-BN was prepared, and the same characterization techniques from the first phase were repeated to evaluate the impact of surface modification on the composite’s properties. The results showed an improvement in mechanical strength with respect to the same load of non-modified filler (43 vs 37 MPa for the tensile strength and 61 vs 55 MPa for the flexural), in accordance with the SEM images from which both an improved adhesion and an exfoliation effect of the treatment on the particles was observed.