A SUSPENSION POLYMERIZATION PROCESS FOR MANUFACTURING ULTRA HIGH MOLECULAR WEIGHT POLYETHYLENE, A MULTIMODAL ULTRA HIGH MOLECULAR WEIGHT POLYETHYLENE HOMOPOLYMERIC OR COPOLYMERIC COMPOSITION, A ULTRA HIGH MOLECULAR WEIGHT POLYETHYLENE, AND THEIR USES

摘要

The present invention relates to a suspension polymerization process for the production of ultra high molecular weight polyethylene, wherein the operation is carried out in at least two reactors of the CSTR type (continuous stirring tank reactor), in a serial configuration, wherein the first reactor is fed with solvent, monomer and, optionally, comonomer; Ziegler-Natta type catalyst, said catalyst composition having a chloride concentration of at least 55%, based on its composition, and preferably more than 76%, chlorinated cocatalyst and chain growth regulator, said continuous stirring tank reactor being kept under a pressure between 0.1 to 2.0 MPa and temperature from 40°C to 100°C, which contents of the first reactor are transferred to the subsequent reactor, by means of a pressure differential or through pumping, wherein said subsequent reactors are kept under a pressure between 0.1 to 2.0 MPa and temperature from 40°C to 100°C, and fed with solvent, monomer, and, optionally, comonomer, catalyst, cocatalyst and chain growth regulator, the pressure and temperature in each of the reactors being different from one another up to the 'nth' reactor, the number of reactors 'n' varying from 2 to 4; the suspension thus obtained in reactor 'n' being centrifugated for the removal of solvent and dried in a fluidized bed drier; thereby resulting in an ultra high molecular weight polyethylene homopolymeric or copolymeric composition with polydispersity greater than or equal to 6.