Use of at least one hemi-peroxyacetal, alone or in combination with other peroxides, to initiate the polymerization or copolymerization of ethylene under high pressure

摘要

The present invention relates to the use of at least one peroxide chosen from the group consisting of hemi-peroxyacetals, alone or in combination with one or more separate additional peroxide(s), for the polymerization or radical copolymerization under high pressure of ethylene. The invention also relates to a process for the preparation of polyethylene comprising a stage of radical polymerization or copolymerization of ethylene under high pressure in the presence of at least one peroxide chosen from the group consisting of hemi-peroxyacetals, alone or in combination with one or more distinct additional peroxide(s). The present invention also relates to a composition comprising ethylene, at least one peroxide chosen from the group consisting of hemi-peroxyacetals, and optionally one or more additional peroxide(s) distinct from the hemi- peroxyacetals. Reference: no figure