Zeolite supported polymerization catalysts: Copolymerization of ethylene and α-olefins with metallocenes supported on HY zeolite

✍ Scribed by Marco Michelotti; Angelina Altomare; Francesco Ciardelli; Eckehart Roland

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 123 KB
• Volume: 129
• Category: Article
• ISSN: 1381-1169
• DOI: 10.1016/s1381-1169(97)00154-4

✦ Synopsis

Copolymerization of ethylene with higher a-olefins, such as 4-methyl-1-pentene, 1-hexene, 1-octene and 1-dodecene, was carried out with both aspecific and isospecific bridged metallocene complexes, comparing the catalytic behaviour Ž . following metallocene supportation on methylalumoxane-pretreated HY zeolite SiO rAl O s 5.7 . A decrease in specific 2 2 3 activity was generally observed after adsorption on zeolite of both non bridged and ansa-metallocene complexes, though molecular weights of the copolymers were found to be higher especially when employing a-olefins as polymerization solvents. On the other side, the incorporation of the a-olefin comonomer was reduced in the case of supported biscyclopentadienylzirconium dichloride, whereas similar contents of olefin units were incorporated in the copolymers prepared with soluble or supported ansa-zircono-or hafnocene. NMR analysis and DSC determined melting points of the produced copolymers are connected with a shape selectivity effect promoted by the support. q 1998 Elsevier Science B.V.