Other

Alexandr Grigorievich Liakumovich

Boris Izrailevich Pantukh

Jury Ivanovich Michurov

Valerian Mikhailovich Sobolev

Yakov Abramovich Gurvich

Grigory I Rutman

Nina Vasilievna Zakharova

Alexandr Afroimovich Grinberg

Felix Borisovich Gershanov

Aida Pavlovna Zakharova

Vladimir Alexeevich Tulupov

Almira Mudarisovna Nafikova

Vitaly Ivanovich Butin

Zoya Stephanovna Baiburina

Tatyana M Lesteva

A process for purifying isoprene produced by catalytic decomposition of dimethyldioxane from carbonyl compounds and cyclopentadiene which involves passing isoprene at a temperature of 40.degree. to 70.degree. C. through a bed of a solid product such as an anion exchange resin or alkali (the latter may be used with or without an inert carrier), followed by subjecting the isoprene to close fractionation performed with at least 50 theoretical plates and at a reflux ratio of at least 3. The process of the present invention enables practically complete purification of isoprene from carbonyl compounds and cyclopentadiene. The purified isoprene, when used as a monomer in the production of stereospecific isoprene rubber, results in high-quality products; and reduces by a factor of 2-3 the Ziegler catalyst consumption in the isoprene rubber synthesis.

Process for purifying isoprene

A method of inhibiting the thermopolymerization of isoprene or butadiene in the process of isolation thereof by extractive distillation from a mixture of hydrocarbons obtained in dehydrogenation of isopentane and butane. The method of inhibiting includes, prior to the introduction of said mixture of hydrocarbons and a polar extractant into an extractive distillation metal apparatus, treating the surface of the apparatus with a 1-25% aqueous solution of passivators, viz. nitrites, sulphites or phosphates of alkali metals at a temperature of 20.degree.-100.degree.C. The mixture of hydrocarbons and the polar extractant with an inhibitor of isoprene or butadiene thermopolymerization introduced into the polar extractant are then fed into said apparatus in an amount of 0.01-1% of the extractant weight. The present method makes it possible to reduce markedly the formation of isoprene and butadiene and, hence, to prevent the plugging of the extractive distillation apparatuses with the aforementioned thermopolymers.

Method of inhibiting the thermopolymerization of isoprene and butadiene

A method of producing 2,6-dialkyl- and 2,6-diaralkyl-substituted derivatives of p-cresol of the general formula ##SPC1## Wherein R signifies an alkyl group having from 4 to 12 carbon atoms or ##SPC2## Comprising subjecting phenol to alkylation with olefines having from 4 to 12 carbon atoms or with styrene at a temperature of 50.degree.-150.degree.C in the presence of a catalyst, namely, aluminum, taken in an amount of 0.1-5 wt.% of phenol. 2,6-Dialkyl phenol or 2,6-diaralkyl phenol resulting after from the alkylation is treated with a mixture of formaldehyde and dimethylamine or with a product of their interaction having the formula ##EQU1## at a temperature of 20.degree.-100.degree.C with subsequent catalytic hydrogenolysis of N,N-dimethyl(3,5-dialkyl-4-hydroxybenzyl)/amine or N,N-dimethyl(3,5-diaralkyl-4-hydroxybenzyl/amine at a temperature of 80.degree.-200.degree.C., molar ratio of hydrogen to the product being treated of 1-5:1 and space velocity of 0.1-2 hour.sup..sup.-1. The products produced by said method feature a high degree of purity, and they can be employed as effective inhibitors of thermooxidation degradation of polymers and hydrocarbon fuels, and also as intermediates for producing p-cresol, and 2-alkyl- and 2-aralkyl-substituted derivatives of p-cresol.

Method of producing 2,6-dialkyl- and 2,6-diaralkyl-substituted

Growing community of inventors

Sterlitamak, undefined

Alexandr Grigorievich Liakumovich