The Protective Role of Conductive Carbon Black in Plastics

With the continuous economic development, the demand for conductive carbon black in various industries has been steadily increasing due to its outstanding performance and versatility. However, how much do we truly understand about its protective effects on plastics? Let's delve into the insights provided by carbon black engineers from Xinxiang Delong Chemical Co., Ltd., a leading manufacturer in this field.

UV Protection and Light Stabilization

One of the primary applications of carbon black in the plastics industry is its role as a UV light stabilizer. Due to its high light absorption properties, carbon black effectively prevents plastics from undergoing photo-oxidative degradation when exposed to sunlight. It functions by converting light energy into heat, shielding plastic surfaces from harmful UV rays, and trapping free radicals to inhibit catalytic degradation. UV radiation is particularly detrimental to polyolefins, and experiments have shown that carbon black with a specific fineness can achieve perfect UV shielding at a concentration of 2%.

Factors Influencing UV Protection

According to Delong's conductive carbon black engineers, the protective effects of carbon black against UV aging in plastics depend on several factors, including particle size, structure, and surface chemistry.

Particle Size

Smaller carbon black particles have a larger surface area, enhancing their light absorption and shading capabilities, thus improving UV protection. However, when particle size falls below 20nm, the protective effect plateaus due to reduced backward scattering, allowing more forward light to threaten polymer stability.

Structure

Carbon black with a lower structure, characterized by smaller aggregate sizes, offers better protection to polymers due to their reduced geometric volume. This also explains why lower-structure carbon black appears darker.

Surface Chemistry

Carbon black with a higher content of oxygen-containing groups (higher volatiles) can neutralize radicals generated during polymer decomposition, thereby enhancing its protective effects.