1503 results about "Dicyclopentadiene" patented technology

The invention is directed to olefin polymerization processes using bridged hafnocene catalyst complexes comprising highly substituted noncoordinating anions that are surprisingly stable under high temperature olefin polymerization processes such that olefin copolymers having significant amount of incorporated comonomer can be prepared with high molecular weights. More specifically, the invention is a polymerization process for ethylene copolymers having a melt index of about 0.87 to about 0.930 comprising contacting, under homogeneous polymerization conditions at a reaction temperature at or above 140° C. to 225° C., ethylene and one or more comonomers capable of insertion polymerization with a bridged hafnocene catalyst complex derived from A) a biscyclopentadienyl hafnium organometallic compound having i) at least one unsubstituted cyclopentadienyl ligand or aromatic fused-ring substituted cyclopentadienyl ligand, ii) one aromatic fused-ring substituted cyclopentadienyl ligand, iii) and a covalent bridge connecting the two cyclopentadienyl ligands, said bridge comprising a single carbon or silicon atom; and B) an activating cocatalyst, precursor ionic compound comprising a halogenated tetraaryl-substituted Group 13 anion wherein each aryl substituent contains at least two cyclic aromatic rings.

The invention discloses a novel method for performing a copolymerization reaction of dicyclopentadiene and maleic anhydride, and belongs to the technical field of copolymers. The method comprises the following steps of: under the protection of nitrogen, adding monomers and an initiator into an organic medium and dissolving, reacting for 2 to 12h at the temperature of between 60 and 90 DEG C to obtain a self-stabilizing dispersion system of monodisperse microspheres of an alternating copolymer, and performing centrifugal separation, and drying to obtain a white solid of the dicyclopentadiene / maleic anhydride alternating copolymer, wherein the reaction monomers are the dicyclopentadiene and the maleic anhydride, and the molar ratio of the two monomers is 5:1-1:5; the medium is a mixed solvent of organic acid alkyl ester and organic alkane, and the organic acid alkyl ester accounts for 30 to 70 volume percent of the mixed solvent; and a chemical structure is that: R1 is a hydrogen atom, C1-C5 alkyl, phenyl or benzyl, and R2 is C1-C5 alkyl. A stabilizer and a costabilizer are not required to be added, the reaction system is simple, and a product is easy to separate; and polymer microspheres have smooth and clean surfaces, uniform particle sizes, controllable appearances, and high dispersibility.