Abstract: A method of preparing trans-, trans-, trans-1,5,9-cyclododecatriene which comprises cyclotrimerization of butadiene at a temperature within the range of from 50.degree. to 150.degree. C. in the presence of a catalytic system consisting of a compound of bivalent nickel, an organo-aluminium compound of the formula (1) or (2):R.sub.3 Al (1)andR.sub.2 Al--X (R').sub.n (2)wherein R, and R' are each C.sub.2 H.sub.5 --, ##STR1## X is --O-- when n=1 and --N-- when n=2; and an activator, viz. a compound of formula (3) or (4):R.sub.3 Si--OR' (3)wherein R is an alkyl; R' is an alkyl, C.sub.6 H.sub.5 --, C.sub.6 H.sub.11,N(CRR'--CRR"--O).sub.3 B (4)wherein R and R" are each CH.sub.3 --, C.sub.2 H.sub.5 --, C.sub.6 H.sub.10, C.sub.8 H.sub.11 --, H--; R is H--.The method according to the present invention makes it possible to increase the yield of the desired product up to 95% by weight.

Abstract: A process for producing high-impact polystyrene which comprises polymerization of styrene in the presence of a reinforcing agent, i.e. a conjugated diolefin polymer, random copolymer, graft-copolymer or block-copolymer of a conjugated diolefin with styrene or a mixture of said copolymers and an anionic catalyst based on organic derivatives of alkali metals or adducts thereof in a medium of inert hydrocarbon solvents such as aliphatic, cycloaliphatic and aromatic solvents or mixtures thereof. On completion of polymerization the resulting polymer is subjected to cross-linking by means of peroxide compounds or redox systems, followed by isolation of the desired product.The process for producing high-impact polystyrene according to the present invention makes it possible to shorten the technological cycle due to increased polymerization rate, to facilitate production technology, and to manufacture polystyrene with improved properties.

Abstract: A method of separating proximate boiling-point hydrocarbons using solutions of monovalent copper salts in solvents, said solvents being alkyl-substituted amides and alkyl esters of phosphorus-containing acids having a P.dbd.O group, N-alkyl-substituted amides of carboxylic acids, N-alkyl-substituted lactams, dialkyl sulphoxides, alkoxynitriles and N-alkyl-substituted aminonitriles. The method can be used for separating hydrocarbons from small quantities of acetylene compounds and cyclopentadiene.Large quantities of acetylene compounds are separated from the mixture of proximate boiling-point hydrocarbons by contacting the mixture with said solvents containing no salts of monovalent copper.