Which additive prevents discolouration due to heat?

• A. Biobatch
• B. Thermal antioxidants prevent discolouration due to heat
• C. Fillers reduce volume of polymer needed
• D. Pigments give colour

Answer: (B)

Heat can cause polymers to oxidize when they’re heated, creating new colored compounds that make the material discolour. The additive that stops this is a thermal antioxidant or heat stabilizer, which works by neutralising free radicals and decomposing reactive peroxides formed during heating. This slows down or prevents the chemical reactions that create colour changes, so the material keeps its appearance under high temperatures. Other options don’t prevent heat-induced colour change: fillers mainly alter density or mechanics, pigments add or modify colour (and can even degrade or shift color with heat), and Biobatch isn’t a standard heat-stabilising additive.