Abstract: A process for the continuous synthesis of a diene elastomer by n reactors r1 to rn, n ranging from 2 to 15, is provided. The reactor r1 is fed by an input solution comprising a solvent, one or more monomers, an anionic polymerization initiator and a polar agent, one or more of the reactor(s) r2 to rn also being fed by reinjection of a purified solution comprising solvent and/or monomer(s), the purity of the or of each reinjected solution being such that the proportion of the number of dead chains in the output stream from the reactor rn is less than 30%, of the number of living chains initiated in the reactor r1, the temperature of each reactor ranging from 20 to 150° C. and being greater than or equal to the temperature of the reactor which immediately precedes it, the diene elastomer having a polydispersity index of 1.1 to 2.

Abstract: The invention relates to a method for producing 1,3-butanediene from a butanediol feedstock that includes: a) A step for esterification of butanediol by a carboxylic acid to form the corresponding diester; b) A step for pyrolysis of the diester effluent obtained from step a); c) A step for distillation fed by at least the carboxylic acid effluent obtained from step a), and producing an aqueous distillate and a carboxylic acid residue; d) A step for drying the carboxylic acid that is fed at least by the carboxylic acid residue obtained from step c) and producing a water effluent and a carboxylic acid product that feeds step a).

Abstract: A modified diene elastomer is provided. The elastomer comprises: at least 70% by weight, with respect to the total weight of the modified diene elastomer, of a linear diene elastomer functionalized predominantly in the middle of the chain by an alkoxysilane group, optionally partially or completely hydrolysed to give silanol, the alkoxysilane group optionally bearing another functional group capable of interacting with a reinforcing filler, the alkoxysilane group bonded to the two branches of the diene elastomer via the silicon atom, the functionalized diene elastomer exhibiting a polydispersity index before fractionalization of less than or equal to 1.6; and more than 0 and up to 30% by weight, with respect to the total weight of the modified diene elastomer, of a star-branched diene elastomer exhibiting a polydispersity index before star-branching of less than or equal to 1.6, the Mooney viscosity of the modified diene elastomer varying from 30 to 80.

Abstract: A process for the continuous synthesis of a modified diene elastomer includes: polymerization by n reactors r1 to rn equipped with an internal stirring system, the reactor r1 being fed by an input solution comprising a solvent, one or more monomers, an anionic polymerization initiator and a polar agent, one or more of the reactors being fed by reinjection of a purified solution comprising solvent and/or monomer(s), the number of dead chains in the output stream from the reactor rn is less than 30% of the number of living chains initiated in the reactor r1, the temperature of each reactor varying from 20° C. to 150° C.; and modification of the living diene elastomer obtained in the preceding stage and exhibiting a polydispersity index varying from 1.1 to 2, making it possible to introduce, into the elastomer, a functional group comprising at least one silicon atom directly connected to the elastomer chain.

Abstract: The invention relates to a conversion method that is fed with a diol feedstock that comprises at least 90% by weight of diol and a carboxylic acid feedstock that comprises at least 80% by weight of carboxylic acid. The method comprising at least: An esterification step which is fed with at least the diol feedstock and at least the carboxylic acid feedstock, wherein the carboxylic acid/diol molar ratio at the inlet of the esterification step is between 2 and 6, the esterification step comprises at least one reactive distillation column that has a mixed reaction/separation zone located between two separation zones; and A water elimination step that is fed with distillate from the esterification step that comprises water and producing at least one water effluent.

Abstract: A method for producing 1,3-butadiene from a 1,4-butanediol feedstock: One step for esterification of 1,4-butanediol, One step for pyrolysis of 1,4-butanediol diester, producing butadiene.

Abstract: A modified diene elastomer comprises: at least 55% by weight of entity coupled by a functional group bearing a function of formula —SiOR, in which R is a hydrogen atom or an alkyl radical, and optionally bearing another function capable of interacting with a reinforcing filler, from 5% by weight to 30% by weight of star-branched entity having three elastomeric branches connected to one and the same silicon atom belonging to a functional group bearing or not bearing a function capable of interacting with a reinforcing filler, less than or equal to 15% by weight of entity functionalized at the chain end by a functional group bearing a function —Si(OR)2, in which R is a hydrogen atom or an alkyl radical, and optionally bearing another function capable of interacting with a reinforcing filler, and a content of less than or equal to 15% by weight of non-functional diene elastomer.

Abstract: The invention relates to a method for producing 1,3-butanediene from a butanediol feedstock that includes: a) A step for esterification of butanediol by a carboxylic acid to form the corresponding diester; b) A step for pyrolysis of the diester effluent obtained from step a); c) A step for distillation fed by at least the carboxylic acid effluent obtained from step a), and producing an aqueous distillate and a carboxylic acid residue; d) A step for drying the carboxylic acid that is fed at least by the carboxylic acid residue obtained from step c) and producing a water effluent and a carboxylic acid product that feeds step a).

Abstract: A process for the continuous synthesis of a modified diene elastomer includes: polymerization by n reactors r1 to rn equipped with an internal stirring system, the reactor r1 being fed by an input solution comprising a solvent, one or more monomers, an anionic polymerization initiator and a polar agent, one or more of the reactors being fed by reinjection of a purified solution comprising solvent and/or monomer(s), the number of dead chains in the output stream from the reactor rn is less than 30% of the number of living chains initiated in the reactor rl, the temperature of each reactor varying from 20° C. to 150° C.; and modification of the living diene elastomer obtained in the preceding stage and exhibiting a polydispersity index varying from 1.1 to 2, making it possible to introduce, into the elastomer, a functional group comprising at least one silicon atom directly connected to the elastomer chain.

Abstract: A system for the continuous synthesis of a modified diene elastomer is provided. The system comprises a device for modifying a living diene elastomer resulting from an anionic polymerization step, modelled on one of the following models: 1. a tubular reactor with axial dispersion, 2. a tubular reactor with axial dispersion, in series with at least one continuous stirred reactor, presumed to be perfectly stirred, 3. at least one tubular reactor with axial dispersion, in series with a continuous stirred reactor, presumed to be perfectly stirred, 4. several tubular reactors with axial dispersion, in series with several continuous stirred reactors, presumed to be perfectly stirred, 5. at least two continuous stirred reactors, presumed to be perfectly stirred, in series.

Abstract: A modified diene elastomer is provided. The elastomer comprises: at least 70% by weight, with respect to the total weight of the modified diene elastomer, of a linear diene elastomer functionalized predominantly in the middle of the chain by an alkoxysilane group, optionally partially or completely hydrolysed to give silanol, the alkoxysilane group optionally bearing another functional group capable of interacting with a reinforcing filler, the alkoxysilane group bonded to the two branches of the diene elastomer via the silicon atom, the functionalized diene elastomer exhibiting a polydispersity index before fractionalization of less than or equal to 1.6; and more than 0 and up to 30% by weight, with respect to the total weight of the modified diene elastomer, of a star-branched diene elastomer exhibiting a polydispersity index before star-branching of less than or equal to 1.6, the Mooney viscosity of the modified diene elastomer varying from 30 to 80.

Abstract: A process for the continuous synthesis of a diene elastomer by n reactors r1 to rn, n ranging from 2 to 15, is provided. The reactor r1 is fed by an input solution comprising a solvent, one or more monomers, an anionic polymerization initiator and a polar agent, one or more of the reactor(s) r2 to rn also being fed by reinjection of a purified solution comprising solvent and/or monomer(s), the purity of the or of each reinjected solution being such that the proportion of the number of dead chains in the output stream from the reactor rn is less than 30%, of the number of living chains initiated in the reactor r1, the temperature of each reactor ranging from 20 to 150° C. and being greater than or equal to the temperature of the reactor which immediately precedes it, the diene elastomer having a polydispersity index of 1.1 to 2.

Abstract: A continuous method for synthesizing a diene elastomer includes modifying the diene elastomer in a functionalizing device by: a kinetic model according to which the ratio of the rate constants is greater than 1, and a flow represented by a residence time distribution in the functionalizing device that is expressed according to equations 1 or 3: (i) in a functionalizing device having at least one tubular continuous reactor or having at least one cascade of at least two stirred reactors, E 1 ? ( t ) = 1 2 ? ( P ?? 1 ? t ) 1 2 ? e - P ? ( ? 1 - t ) 2 4 ? ? 1 ? t Eq ? ? 1 (ii) in a functionalizing device that is a combination of the device (i) and of a device having at least one continuous stirred reactor, having a residence time distribution characterized by the following equation: E 2 ? ( t ) = e ( - t ? 2 ) ? 2 Eq ? ? 2 the device (ii) having a residence time distribution characterized by the

Abstract: A method for producing 1,3-butadiene from a 1,4-butanediol feedstock: One step for esterification of 1,4-butanediol, One step for pyrolysis of 1,4-butanediol diester, producing butadiene.

Abstract: The invention relates to a conversion method that is fed with a diol feedstock that comprises at least 90% by weight of diol and a carboxylic acid feedstock that comprises at least 80% by weight of carboxylic acid. The method comprising at least: An esterification step which is fed with at least the diol feedstock and at least the carboxylic acid feedstock, wherein the carboxylic acid/diol molar ratio at the inlet of the esterification step is between 2 and 6, the esterification step comprises at least one reactive distillation column that has a mixed reaction/separation zone located between two separation zones; and A water elimination step that is fed with distillate from the esterification step that comprises water and producing at least one water effluent.

Abstract: The present invention relates to a modified diene elastomer predominantly comprising a species coupled via a group bearing a function comprising a silicon atom predominantly hydrolyzed into silanol and a tertiary amine function, linked to the diene elastomer via the silicon atom, and to the process for synthesizing the modified diene elastomer. This elastomer has the particular feature of not undergoing any change in Mooney viscosity during its storage.

Abstract: The invention relates to a functionalized diene elastomer composed: a) of a diene elastomer functionalized, at the chain end or in the middle of the chain, by a tin functional group, exhibiting a monomodal distribution of molecular weights before functionalization and a polydispersity index before functionalization of less than or equal to 1.3, b) of a diene elastomer star-branched with a tin compound, exhibiting a monomodal distribution of molecular weights before star-branching and a polydispersity index before star-branching of less than or equal to 1.3, and c) of a content of less than 15% by weight, with respect to the total weight of the functionalized diene elastomer, of a non-tin-functional diene elastomer, the said diene elastomers a), b) and c) being, before optional functionalization or optional star-branching, the same in nature.

Abstract: The present invention relates to a modified diene elastomer predominantly comprising a species coupled via a group bearing a function comprising a silicon atom predominantly hydrolysed into silanol and a tertiary amine function, linked to the diene elastomer via the silicon atom, and to the process for synthesizing the modified diene elastomer. This elastomer has the particular feature of not undergoing any change in Mooney viscosity during its storage.

Abstract: A modified diene elastomer, a process of preparing the elastomer is provided. The modified diene elastomer comprises: (i) from 40 to 80% by weight of the entity functionalized at the chain end by an alkylalkoxysilane group, optionally partially or completely hydrolysed to give silanol, bearing a primary, secondary or tertiary amine function, and bonded to the elastomer via the silicon atom, (ii) from 5 to 45% by weight of the entity functionalized in the middle of the chain by an alkoxysilane group, optionally partially or completely hydrolysed to give silanol, bearing a primary, secondary or tertiary amine function, and the silicon atom of which bonds the two pieces of the chain, (iii) from 3 to 30% by weight of the three-branch star-branched entity containing a silane functional group, bearing a primary, secondary or tertiary amine function, and the silicon atom of which bonds the three branches of the chain.

Abstract: A continuous method for synthesizing a diene includes modifying the diene elastomer in a functionalizing device by: a kinetic model according to which the ratio of the rate constants is greater than 1, and a flow represented by a residence time distribution in the functionalizing device that is expressed according to equations 1 or 3: (i) in a functionalizing device having at least one tubular continuous reactor or having at least one cascade of at least two stirred reactors, E 1 ? ( t ) = 1 2 ? ( P ?? 1 ? t ) 1 2 ? ? - P ? ( ? 1 - t ) 2 4 ? ? 1 ? t Eq ? ? 1 (ii) in a functionalizing device that is a combination of the device (i) and of a device having at least one continuous stirred reactor, having a residence time distribution characterized by the following equation: E 2 ? ( t ) = ? ( - t ? 2 ) ? 2 Eq ? ? 2 the device (ii) having a residence time distribution characterized by the e