Enhancing Thermal and Mechanical Properties of Soft PVC Composites With Phosphorylated Boron Nitride

ABSTRACT In the present study, hexagonal boron nitride (h‐BN) nanosheets were first functionalized with hydroxyl groups (h‐BN‐OH), and then phosphonic acid groups were grafted onto the h‐BN surface (BNP) using aminotris(methylenephosphonic acid) (ATMP) through a condensation reaction. The BNP was then incorporated into a polyvinyl chloride (PVC) matrix to prepare PVC/BNP composites. Thermogravimetric analysis showed an increase in thermal stability, with BNP/PVC composites exhibiting greater resistance to degradation at elevated temperatures. The addition of BNP improved the dispersion and interfacial adhesion within the PVC matrix, as confirmed by Scanning Electron Microscopy (SEM). Furthermore, the PVC/BNP composites exhibited a 22.5% increase in tensile strength (21.2 MPa) and an 82% improvement in elongation at break (464%) compared to pristine PVC composites, which showed a tensile strength of 17.3 MPa and an elongation at break of 255%. Moreover, the addition of BNP notably improved the thermal conductivity from 0.18 to 1.50 W/m K as the BNP content increased from BNP‐0 to BNP‐4. These improvements in thermal stability and mechanical strength, as well as excellent migration resistance, make BNP/PVC composites highly promising for advanced applications.