The dissolution of four sterically hindered amines with molecular weights f
rom 1364 to 2758 was studied in polypropylene in the interval, 60-130 degre
es C. The solubility of the additives at 100 degrees C passes through a max
imum during time and the maximum solubility increases with increasing addit
ive molecular weight. The rearrangement of the polymer structure during add
itives dissolution is discussed. (C) 2000 John Wiley & Sons, Inc.