Fabrication of Vinyl Ester-Modified Phenolic Resin Composite Coatings for the Protection of Combustible Cartridge Cases

To improve the protection of combustible cartridge cases (CCCs), four vinyl ester-modified phenolic resins (VEPRs) were prepared. Fourier transform infrared spectroscopy was used to identify the chemical structure of the coatings. Subsequently, the surface element composition of each coated sample was analyzed by X-ray photoelectron spectroscopy. The thermal properties were evaluated using thermogravimetric analysis, differential scanning calorimetry, and a heat resistance test. Additionally, the hydrophobicity of the composite coatings was examined through scanning electron microscopy, water contact angle measurement, and a salt wet test. All coated CCCs possessed excellent heat resistance. The 20 wt % VEPR-coated CCCs possessed the optimum hydrophobic property with the highest water contact angle of 112.5° and exhibited the longest heat resistance time of 111 s at 250 °C, indicating optimal performance in preventing heat from penetrating the CCCs. Therefore, the results indicate that the newly developed composite coating formulations significantly improve the protection of CCCs.