Washing out oligomeric triazinic‐hindered amine from polypropylene

Washing oligomeric and monomeric triazinic sterically hindered amines out of polypropylene (PP) using heptane, dodecane, a mixture of heptane and dodecane, and ethanol was studied at 20°C and 40°C. Stabilizers leaked from the polymer in heptane and dodecane but only slightly in ethanol. Also studied was washing out separate fractions of the oligomeric stabilizer in these solvents. The rate of loss depended on their molecular weight and on their concentration in the polymer. It was learned that the rate of washing out oligomeric stabilizer from PP could be predicted based on its fractions; some discrepancy was observed when most of the additive leaked.