# Structure–Property Relationships of Boron Nitride-Reinforced Glass Fiber/Epoxy Laminated Composites

## TL;DR

This paper studies how adding boron nitride particles improves the strength, thermal stability, and electrical properties of glass fiber/epoxy composites.

## Contribution

The study systematically evaluates the effects of h-BN particle size and content on mechanical, thermal, and electrical properties of composites.

## Key findings

- 65–75 nm h-BN at 0.2 wt.% improves tensile and shear strengths.
- 790 nm h-BN at 0.4 wt.% enhances impact resistance and hardness.
- h-BN increases Tg and maintains electrical insulation with limited resistivity reduction.

## Abstract

Advances in modern industry largely depend on the development of high-performance materials. In this study, the influence of hexagonal boron nitride (h-BN) filler on the performance of glass fiber/epoxy laminates was systematically investigated. Composites containing h-BN with different particle sizes (65–75 nm and 790 nm) and contents (0.2 and 0.4 wt.%) were fabricated, and their mechanical (tensile, in-plane shear, hardness, impact), thermal (Differential Scanning Calorimetry, DSC), electrical (volume resistivity), and spectroscopic (Fourier Transform Infrared Spectroscopy, FTIR) properties were examined. The results demonstrated that specimens with 65–75 nm h-BN at 0.2 wt.% exhibited the highest tensile and shear strengths, whereas those with 790 nm h-BN at 0.4 wt.% showed superior impact resistance and hardness. DSC analyses revealed that h-BN addition increased the glass transition temperature (Tg), while FTIR confirmed interfacial interactions between h-BN and the epoxy matrix. Electrical measurements indicated that h-BN preserved the insulating nature of the composites, with only limited reductions in resistivity observed at higher contents of larger particles due to morphological effects. Overall, these findings highlight that h-BN filler enhances load transfer efficiency, thermal stability, and mechanical reliability, offering significant potential for applications requiring multifunctional performance, such as aerospace, marine, and electrical and electronic insulation systems.