Brominated Polyethylene. Synthesis, Photooxidation and Use as the Intermediate for the Preparation of New Polymeric Stabilizers

Abstract

The hydrobromination of polyoctenamer was performed using concentrated hydrogen bromide chloroform solutions. The conditions for the total hydrobromination of polyoctenamer were established. The photoageing of the resulting brominated polyethylene was analyzed and compared with those of pure polyethylene and chlorinated homologues. The brominated polyethylene has been used as an intermediate for the synthesis of a new polymeric hindered amine stabilizer. Nucleophilic substitution of bromine atoms was performed by 4-amino-2,2,6,6-tetramethylpiperidine and resulted in a partial grafting of 2,2,6,6-tetramethylpiperidine groups on the polymer chain. Using 2,2,6,6-tetramethyl and 1,2,2,6,6-penta-methyl-4-piperidinol in the presence of NaH or their sodium salts as the nucleophilic agents did not lead to any grafting under the experimental conditions used. This new additive resulted in good stabilizing properties upon the photo-and the thermooxidation of elastomers as EPDM and polyoctenamer.