Polysiloxanic stabilizers containing sterically hindered phenol groups and reactive groups

A polymeric composition comprising an organic polymer and a stabilizing quantity of a polymeric stabilizer having a formula:

• MX.sub.m Y.sub.p Z.sub.q M'
• wherein ##STR19## M' is --OM, M and M' can optionally form together a direct bond thus producing a cyclic structure,
• R.sub.1 is a phenyl or a linear or branched alkyl radical containing from 1 to 20 carbon atoms,
• R.sub.2 is a reactive organic group which contains a carbon-carbon double bond, an epoxy ring, a sulfide group, or an aminic group,
• R.sub.3 is a linear or branched alkyl radical containing from 1 to 6 carbon atoms,
• R.sub.4 is a radical selected from the group consisting of ##STR20## wherein, R.sub.5 and R.sub.6, which may be the same or different, are linear or branched alkyl radicals which contain from 1 to 10 carbon atoms,
• R.sub.7 is a linear or branched alkylene radical which contains from 3 to 10 carbon atoms,
• R.sub.8 is a linear or branched alkylene radical which contains from 1 to 10 carbon atoms or a biradical selected from the group consisting of --R.sub.9 --COO--R.sub.10, --R.sub.9 --COO--R.sub.11 --,
• R.sub.9, R.sub.10 and R.sub.11, which may be the same or different, are linear or branched alkylene radicals which contain from 2 to 10 carbon atoms,
• R' is a phenyl or a linear or branched alkyl radical which contains from 1 to 10 carbon atoms,
• R" is the same as R', R.sub.2 or R.sub.4,
• m and p, which may be the same or different, are integers from 1 to 50, and
• q is an integer between 0 and 50,
• n is equal to 0 or 1.