Copolymerization of ethylene with higher alpha-olefins

Copolymers of ethylene with 1-octene, 1-decene, 1-dodecene, 1-tetradecene and 1-hexadecene and with 5-butyl-2-norbornene and 5-hexyl-2-norbornene were synthesized using the catalytic system titanium dimethyl[N-(1,1-t-butyl)-1,1-dimethyl-1-[(1,2,3,4,5-η)-2,3,4,5-tetramethyl-2,4-cyclo-pentadien-1-yl]silanaminato(2-)-N], (Cp*SATiMe₂)/MAO under strictly controlled conditions. The polymerization conditions were designed to produce copolymers that contained a high molar content of comonomer from 12 to 40 mol %. The resulting copolymers were analyzed by NMR, IR, SEC, DMA and WAXD characterization as well as by tensile strength testing.; Amorphous copolymers of ethylene with 5-butyl-2-norbornene and 5-hexyl-2-norbornene were synthesized with this catalytic system in an attempt to produce copolymers that contained large amounts of the cyclic olefins for increased T_g and toughness. These novel copolymers containing from 13 to 50 mol % alkylnorbornene were also analyzed by NMR, DSC, GPC and WAXD to determine their basic physical attributes (i.e. molecular weight, melting point etc.).; Following the synthesis of a series of copolymers of ethylene with each comonomer, the monomer reactivity ratios were determined by methods developed by Mayo-Lewis, Fineman-Ross, Kelen-Tüdõs and Penlidis et al (RREVM). While the monomer reactivity ratio for ethylene remained relatively constant (ca. 2.3) in all cases, the monomer reactivity ratio calculated for the comonomer decreased with increasing alkyl side-chain length, being 1.26 for 1-octene and 0.60 for 1-hexadecene.; For the copolymerization of ethylene with the alkylnorbornenes, the monomer reactivity ratios for ethylene increased with increasing alkyl side-chain length from 3.18 for 5-butyl- to 3.68 for 5-hexyl-2-norbornene. The monomer reactivity ratio was calculated to be 0.00 for both alkylnorbornenes.; Finally, the homopolymers of 1-hexene, 1-octene, 1-dodecene, 1-tetradecene, 1-hexadecene and 1-octadecene were synthesized using the unique catalytic system of titanium dimethyl[N,N′-bis[2,6-bis(isopropyl)phenyl]-1,3-propanediaminato(2-)-N,N ′], (diarly diaminato titanium dimethyl)/MAO which produced completely nontactic poly-α-olefins at rates up to 697 kg polymer (mmol Ti hr). The polymers were characterized by NMR, SEC, DSC and WAXD. The chain transfer coefficient of MAO, Al(i-Bu)₃ and Al(Me)₃ with this catalyst were 0.120, 1.184 and 1.702, respectively.