摘要:
This invention relates to a method of preparing a brominated elastomer having a stabilized Mooney viscosity. The method includes polymerizing isomonoolefins and at least one polymerizable unit to obtain an elastomer/polymer; brominating the elastomer/polymer to form a brominated elastomer effluent; neutralizing the brominated elastomer effluent to form a neutralized effluent; volatizing off the hydrocarbon solvent; and recovering a brominated elastomer. In at least one point of the process, preferably prior to any significant temperature change in the brominated polymer, a Mooney stabilizer is added into the system. Portions of the Mooney stabilizer may be added at multiple points into the process.
摘要:
A method of separating a polyisoolefin elastomer from non-polymeric components in an organic solvent involves ultrafiltration of a solution of the polyisoolefin elastomer and non-polymeric components in an organic solvent through a semipermeable membrane to substantially retain the polyisoolefin elastomer in a retentate and provide the non-polymeric components in a permeate. Advantageously, stabilizers for the polyisoolefin elastomer are retained in the retentate along with the polyisoolefin elastomer, permeate flux through the membrane is higher as concentration of the polyisoolefin elastomer in the solution increases up to a concentration limit, the separated polyisoolefin elastomer in the retentate has a molecular weight that can be substantially unchanged even when ultrafiltration is conducted at elevated temperature and the amount of polyisoolefin elastomer in the permeate is unmeasurable providing an oligomer-rich permeate uncontaminated by polyisoolefin elastomer.
摘要:
A copolymer has high levels of multolefin incorporation. A process for producing the copolymer having high levels of multiolefin incorporation involves contacting at least one isoolefin monomer with at least one multiolefin and/or β-pinene monomer in the presence of at least one Lewis acid and at least one initiator in a diluent. The diluent contains a hydrofluorinated olefin (HFO) comprising at least three carbon atoms and at least three fluorine atoms. Hydrofluorinated olefins used in the present invention are better diluents for butyl slurry cationic polymerization than saturated hydrofluorocarbons.
摘要:
A process for producing a copolymer involves contacting at least one isoolefin monomer with at least one multiolefin and/or β-pinene monomer in the presence of at least one Lewis acid and at least one initiator in a diluent. The diluent contains a hydrofluorinated olefin (HFO) comprising a tetrafluorinated propene. Copolymers produced by a process of the present invention have a cyclic oligomer content lower than comparable polymers produced in a butyl rubber slurry process using 1,1,1,2-tetrafluoroethane and/or methyl chloride as a diluent as well as a more favourable ratio of C21/C13. Hydrofluorinated olefins used in the present invention are better diluents for butyl slurry cationic polymerization than saturated hydrofluorocarbons.
摘要:
There is provided a process for producing an ionomer comprising the steps of (a) admixing in a mixer a halogenated copolymer with at least one nitrogen and/or phosphorus based nucleophile and (b) extruding the mixture from step (a). The process takes place with high conversion and the resulting ionomer contains a low amount of residual nucleophile and has a low yellowness index.
摘要:
The invention relates to an efficient process for the preparation and isolation of rubber particles formed in aqueous media having a tunable level of metal containing anti-agglomerants and rubber particles obtained thereby. The invention further relates to copolymer products comprising the same or derived therefrom.
摘要:
The invention relates to a method for the production of halobutyl rubber by copolymerization of isobutyl and isoprene in a solvent to form butyl rubber, wherein the solvent can be non-soluble for a suspension process (for example chloromethane) or be soluble for a solution process (for example, isopentane, pentane, hexane), and the subsequent halogenation of the butyl rubber. According to the invention, at least the halogenation should be carried out using a halogenation agent (8), in particular chlorine or bromine, in a halogenation kneader (7).