Antioxidant is a substance added in small quantities to hydrocarbons which are susceptible to oxidation, such as rubbers, plastics, foods, and oils to inhibit or slow oxidative processes, while being itself oxidized.
There are two basic types of antioxidants: primary and secondary . Primary antioxidants are defined as additives that intercept and stabilize free radicals by donating an active hydrogen atom, gaining their name “radical scavengers”. Secondary antioxidants prevent the further formation of free radicals by decomposing unstable hydroperoxides prior to their homolytic cleavage.
Secondary antioxidants perform better with the incorporation of a primary antioxidant. However, not every type of primary antioxidant can be incorporated with any type of secondary antioxidant.
Antioxidants are employed to retard the degradation of polymers due to air oxidation. Free radicals are initiated by reactions within the polymer brought-on by heat, ultraviolet radiation, mechanical shear or metallic impurities
DLTDP, DTTDP and DSTDP are all produced by reacting the same intermediate, thiodipropionitrile (TDPN), with different fatty alcohols. DLTDP uses lauryl alcohol, DTTDP uses iso-tridecyl alcohol and DSTDP uses stearyl alcohol.