METHOD OF PRODUCING HIGHLY REACTIVE LOW MOLECULAR WEIGHT POLYISOBUTYLENE Russian patent published in 2025 - IPC C08F110/10 C08F10/10 C08F4/14 

FIELD: chemistry.

SUBSTANCE: invention relates to the technology of producing highly reactive low-molecular weight polyisobutylene and can be used in the industry of synthetic rubber, and the obtained product can be used as a base for producing succinimide additives, a thickening additive for fuels, lubricating oils and grease, a gluing agent when making stretch films, a modifier for vulcanised and other elastomers, and when making adhesives and sealants. Highly reactive low molecular weight polyisobutylene is obtained by polymerisation of isobutylene in a medium of a hydrocarbon solvent in a cascade of polymerisers in the presence of a Friedel-Crafts catalyst and a rate controller, which is a mixture of dimers, trimers and tetramers of isobutylene with weight ratio (dimer):(trimer):(tetramer) equal to (5-35):(55-90):(5-10), in amount of 0.5-4 wt. % to isobutylene or a return fraction of isobutylene oligomers consisting of dimers, trimers and tetramers of isobutylene in weight ratio (dimer):(trimer):(tetramer) equal to (10-25):(66-89):(1-9), which is recovered from polymerisation products, in amount of 0.2-5 wt. % to isobutylene. Catalyst used is a pre-formed complex (BF₃)×(ROH) containing a coinitiator selected from a group of compounds of general formula ROH, where R is methyl, ethyl, isopropyl, n-butyl, isobutyl, phenyl is a radical, with molar ratio (BF₃):(ROH) equal to 1:(0.01-3). Process is carried out in a medium of boiling isobutane at a temperature of minus 15 to plus 15 °C and dosage of catalytic complex according to BF₃ 0.01-0.35 wt. % to isobutylene.

EFFECT: method enables to obtain low-molecular highly reactive polyisobutylene with reactivity, molecular weight and polydispersity coefficient controlled in a wide range of values, which provides expansion of the field of application of the obtained product, as well as simplification of technology and improvement of technical and economic parameters of the process.

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