Loss of high molecular weight, sterically hindered amines from polypropylene

The loss from polypropylene (PP) of sterically hindered amines with molecul ar weight ranging from 1364 to 2758 in heptane, chloroform, and methanol at room temperature was studied. The additives leak from polymer in heptane a nd in chloroform and some residual concentration remains in the polymer; th e stabilizers show slight migration in methanol. The rate of loss increases with additive concentration in the polymer. The effect of solvent during w ashing out could be explained by its different solubility in PP resulting i n changes in polymer chain mobility and additive migration from the polymer . (C) 2000 John Wiley & Sons, Inc.