Construction of a Novel Barium-Free Green-Light Emitting Illuminant Based on Boron Carbide

Green-light emitting illuminant and green pearls that are currently being used for pyrotechnics are mainly composed of barium carbonate and polyvinyl chloride (PVC), which lead inevitably to the substantial generation of abundant harmful products for environmental pollution. There is thus considerable scope for the development of a novel emitting illuminant with an improved green composition instead of compositions incorporating barium based oxidants and polyvinyl chloride for environmental protection. For this purpose, a new composition composed of boron carbide, potassium perchlorate, and guanidine nitrate with a suitable burning rate of 5 similar to 15 mm/s required for fireworks, the high luminous intensity of 34665 Cd and spectral purity of 67.1 % at a primary wavelength of 562 nm was developed. Notably, PM10 data demonstrated that the new composition generated less than half the amount of the smoke relative to the original one. More importantly, all of the safety parameters of this new formulation meet well with the standards' requirements, i. e., a remarkable low sensitivity to friction (0 %) and impact (8 %), relative stability to electric discharge (374.4 mJ), flame (14.0 cm) and heating (unburned, unexploded at 75 degrees C for 48 h), as well as a high ignition temperature of 504.0 degrees C and a low moisture absorption rate (0.66 %). Taken together, the new emitting illuminant developed herein showed great potential to be used for fireworks and signal flare in both military and civilian applications.

Automated summary

The new emitting illuminant, composed of boron carbide, potassium perchlorate, and guanidine nitrate, replaces the commonly used combination of barium carbonate and PVC, demonstrating great potential in applications such as fireworks and signal flare.