Effect of Silanization Modification of Hexagonal Boron Nitride on the Interface Structure and Barrier Properties of Polyvinylidene Fluoride Composites

ABSTRACT Two‐dimensional layered hexagonal boron nitride (hBN) was surface functionalized by three fluorosilane coupling agents, respectively, and was incorporated into PVDF to prepare PVDF/N‐hBN, PVDF/P‐hBN, and PVDF/Q‐hBN composites to improve the barrier property. The structure and the grafting amount of the silanized‐hBN were confirmed by FTIR, XPS and TGA. The thermal, rheological, mechanical, resistance, and barrier properties of the composites were further determined. The results showed that silanization modification could effectively improve the compatibility between hBN and PVDF and promote the uniform dispersion of hBN within PVDF. The thermal storage performance, mechanical properties, resistivity and barrier properties of the PVDF/silanized‐hBN composites were significantly improved compared with PVDF/hBN composite. For instance, the composite with 6 wt% P‐hBN (hBN modified with (3,3,3‐trifluoropropyl) trimethoxysilane) showed tensile strength of 52.10 MPa, elongation at break of 56.72%, and elastic modulus of 14.0 MPa. The barrier property of PVDF/Q‐hBN (hBN modified with 1H,1H,2H,2H‐perfluorooctyl trimethoxysilane) was most significantly improved. When the Q‐hBN content was 10 wt%, the water vapor and oxygen permeability coefficient of the composites were 5.08 × 10 −15 and 1.55 × 10 −15 cm 3 ·cm/(cm 2 ·s·Pa), decreased by 41.7% and 80.9% compared with PVDF. These findings provide new perspectives for developing advanced pipeline linings and other applications that demand superior barrier performance.