Abstract: Polyolefin polymers can successfully be stabilized against the detrimental effects of UV-radiations by compounding them with a stabilizer belonging to the class of compounds containing a pyrrolidine ring and which are sterically hindered in the 3-position and also substituted in such position by substituents having a high molecular weight. The esters of the 2,2,5,5-tetraalkyl-4-methyl-3-methylol pyrrolidine are exemplary compounds; the adipic and the stearic esters are preferred.

Abstract: For stabilizing polyolefin polymers such as polyethylene and polypropylene against the detrimental effects of exposure to UV-radiations and weathering agents, a stabilizing additive is disclosed which consist of a fatty acid ester of the N-(beta-hydroxyethyl)-2,2,3,4,5,5-hexamethylpyrrolidine. The lauric and palmitic acid esters are preferred.

Abstract: This invention relates to particular polyolefin compositions which contain, as stabilizers against UV-light radiations, open-chain amine compounds which are hindered in the alpha-position by alkyl radicals, said amine compounds corresponding to the following general formula: ##STR1## wherein R', R", R"', R.sup.IV, R.sup.V and R.sup.VI which can be equal or different, are radicals of aliphatic hydrocarbons with a number of C-atoms variable from 1 to 20, or can be hydrogen atoms, n is an integer variable from 2 to 12, and n' is an integer comprised between 1 and 15.