| abstract |
Polymers (including copolymers) derived from one or more olefins, such including ethylene and C3-C20 alpha-olefins such as propylene and 1-butene, which polymers have (a) an average ethylene sequence length, ESL, of from, about 1.0 to less than about 3.0; (b) an average of at least 5 branches per 100 carbon atoms of the polymer chains comprising the polymer; (c) at least about 50% of said branches being methyl and/or ethyl branches; (d) at least about 30% of said polymer chains terminated with a vinyl or vinylene group; (e) a number average molecular weight, Mn, of from about 300 to about 15,000 when the polymer is intended for dispersant or wax crystal modifier uses and up to about 500,000 where intended for viscosity modifier uses; and (f) substantial solubility in hydrocarbon and/or synthetic base oil. The polymers are produced using late-transition-metal catalyst systems and, preferably, inexpensive, highly dilute refinery or steam cracker feed streams that have undergone only limited clean-up steps. Fuel and lubricating oil additives, particularly dispersants, wax crystal modifiers and flow improvers, are produced. Where functionalization and derivatization of these polymers is required for such additives it is facilitated by the olefinic structures available in the polymer chains. |