| 摘要 |
Unsaturated ethylene polymers and processes for preparing and using the same. These polymers are characterized by the process, comprising the step of reacting a saturated, linear polyethylene directly with a diene monomer in the melt phase, the diene monomer having from 1 to about 10 carbon atoms and being present in an amount up to about 5 weight percent of the melt composition. The reaction occurs under mild conditions, including atmospheric pressure and temperatures in the range of between about 250 DEG F. and about 400 DEG F. Moreover, no chemical or irradiant initiation is required. Processes for using these unsaturated polymers in cross-linking and addition reactions are also disclosed, involving reacting such polymers with a saturated, linear polyethylene or with some other polymeric or nonpolymeric functional group susceptable of free-radical addition reaction, the functional component being present in an amount of between about 20 weight percent and about 40 weight percent of the melt phase. Mild conditions are observed and no chemical or irradiant initiation is needed. The pure cross-linked ethylene and other polymers obtained exhibit improved properties, particularly in the cryogenic and dielectric areas.
|
