The invention relates to a process of thermomechanical treatment in the molten state, in the presence of organic peroxides, of co-polymers with a density less than 0.935, obtained by co-polymerization under a pressure of less than 4 MP.sub.a of ethylene and a higher alpha-olefin. The
The invention relates to a process of thermomechanical treatment in the molten state, in the presence of organic peroxides, of co-polymers with a density less than 0.935, obtained by co-polymerization under a pressure of less than 4 MP.sub.a of ethylene and a higher alpha-olefin. The