FIELD: synthetic rubber industry. SUBSTANCE: cyclization catalysts used are effective and accessible for industrial utilization. Catalyst are biologically decomposable and make it possible to carry out cyclization at low temperatures in any solvent in which initial rubber is soluble. To this end, cyclization of polymers of isoprene or copolymers of isoprene with diene or vinyl aromatic monomers is carried out by heating in organic solvent in the presence of catalyst, e.g. alkylsulfonic acid of general formula: 
or -0- in amount of 1-20 wt% per polymer. EFFECT: more efficient preparation process. 3 tbl
| Title | Year | Author | Number |
|---|---|---|---|
| METHOD FOR PRODUCTION OF POLYMERS AFFECTED BY CYCLIZATION | 1992 |
|
RU2067982C1 |
| CYCLOPOLYISOPRENE MANUFACTURE PROCESS | 2002 |
|
RU2224767C1 |
| CYCLOPOLYISOPRENE PRODUCTION METHOD | 2001 |
|
RU2210575C2 |
| CYCLOPOLYISOPRENE MANUFACTURE METHOD | 2002 |
|
RU2223973C1 |
| METHOD OF PRODUCING CATALYST FOR ISOPRENE POLYMERIZATION | 1994 |
|
RU2061546C1 |
| METHOD OF PRODUCTION OF POLYMERIZATION AND COPOLYMERIZATION CATALYST OF UNSATURATED HYDROCARBONS | 1998 |
|
RU2141382C1 |
| POLYISOPRENE CYCLIZATION CATALYST AND METHOD OF PREPARATION THEREOF | 2001 |
|
RU2211225C2 |
| METHOD OF UNSATURATED ELASTOMER HYDROGENATION | 1992 |
|
RU2048477C1 |
| PROCESS FOR PREPARING MODIFIED 1,4-POLYBUTADIENE | 1992 |
|
RU2083592C1 |
| METHOD OF PREPARING BUTADIENE-POLYMERIZATION CATALYST | 1998 |
|
RU2139138C1 |
