PROCEDE POUR LA POLYMERISATION SELECTIVE DE BUTADIENE A PARTIR DE FRACTIONS EN C4

摘要

Butadiene is selectively (co)polymerised from 4C fractions into (co)polymers opt. contg. functional gps., predetermined mol. wts. of e.g. 1000 to several times 100000 and microstructures which may vary in a zone starting from a content higher in -1,4 structure to a content higher in -1,2 structure. Polymsn. is effected in homogeneous phase, opt. in presence of a non-polar solvent and opt with addition of a polar solvation agent, in presence of a Li initiator comprising one of the following: (a) dialkalimetal ditert. diamines, pref. dilithium ditertiary diamines of formula (I) where R and R' are 1-30 (3-15) C alkyl, R"-Li and R'"-Li are aromatic gps. each contg. a Li atom and partly substd. by alkyl gps.; (b) dilithiumdiamides of formula (Li)(R)N-(CH2)n-N(R)(Li) where R is 1-30 (3-20)C alkyl, n being 1-12, pref. 2-6; (c) dilithium adducts of conjugated dienes, opt. substd., contg. 2-6 monomer units per molecule, 1 or 2 Me gps., and 4-12C per diene molecule, and which are prepd. in a mixt. of toluene, benzene or diethyether with THF, the latter forming 5-30 wt.% w.r.t. the mixt. of solvent; (d) polylithium oligodienes contg. 2-4 Li atoms and 2-10 pref. 2-6 diene units per molecule, and prepd. in a non polar solvent; (e) butanes dilithim prepd. in an asymmetric ether having a flash pt. greater than 473 K; (f) dilithium diphenolethers of formula (II) where n is 1-20 (2-6), the Li atoms being in o- or p- positions. Polybutadiene can be prepd. from 4C fractions, partic. olefin mixts., without sepn., and obtd. during the pyrolysis of petroleum, as source of butadiene. Purificn. of the butadiene before polymsn. is avoided and only the butadiene is polymerised to give a polymer having the properties of one obtd. from the pure monomer. The remaining (un)satd. prods. in the 4C fraction can be used for other reactions.