Abstract: The present invention provides method for recovering fossil-based materials from oil sources using multifunctional, multipolymeric continuous composition spectrum surfactant mixtures. The invention also provides methods for reducing the loss of volatile organic compounds (VOCs) from oil storage containers using multifunctional, multipolymer surfactants. The multifunctional, multipolymer surfactants are characterized by a hydrophobic part and a hydrophilic part. The hydrophobic part of the polymer surfactants includes functionalities that impart a polarity of greater than 0 Debye to the hydrophobic part. The polymer surfactants are further characterized by molecular weights that are above their entanglement weights. The result is polymer surfactants and their continuous composition surfactant-thickener mixtures with demulsifying characteristics.

Abstract: Polymer dispersions of polymers derived from silicone macromers and ethylenically unsaturated monomers are capable of incorporating large amounts of chemically bonded macromer, when the silicone macromer and part of the unsaturated monomer are polymerized in aqueous medium as an initial charge with an oil soluble initiator, and the remaining monomers are fed in and polymerized using a water soluble initiator. The dispersions may be dried to form water redispersible polymer powders.

Abstract: A nozzle for catalyst injection for olefin polymerization is provided. In one or more embodiments the nozzle includes a first conduit including a body, a tapered section, and an injection tip. The nozzle also includes a second conduit having an inner surface and an outer surface. The first conduit is disposed about the second conduit defining a first annulus therebetween. The nozzle further includes a support member at least partially disposed about the outer surface of the first conduit defining a second annulus therebetween. The support member has a converging outer surface at a first end thereof.

Abstract: Polymerization processes and polymers formed therefrom are described herein. The polymerization processes generally include contacting an olefin monomer with a catalyst system to form polymer within a reaction vessel, withdrawing polymer from the reaction vessel, contacting the polymer with one or more initiation additives to form a modified polymer and extruding the modified polymer.

Abstract: The invention relates to a method for radical polymerization of one or several ethylenically unsaturated compounds, characterized in that it consists in providing at least 80.8 percent by weight ethylenically unsaturated compounds in relation to the total weight of the ethylenically unsaturated compounds, adding at least one polymerization initiator for radical polymerization in at least two steps, wherein more polymerization initiator is added in the second step than in the first.

Abstract: The invention relates to a process for the manufacture of ethylene polymers and copolymers in which ethylene is compressed in a primary compressor at a throughput of at least 55 tonnes/hour, mixed with recycled ethylene and further compressed in a two-stage reciprocating secondary compressor having at least 14 cylinders to a pressure of at least 2300 bar at a throughput of at least 120 tonnes/hour, heating at least a portion of that ethylene to a temperature of at least 95° C. and introducing it into a tubular reactor of diameter at least 65 mm and a length of at least 1500 m, introducing initiator in at least three reaction zones to give a conversion of at least 28% and maintaining a pressure drop over the reactor to maintain a flow velocity of at least 6 m/s.

Abstract: Polyesters prepared using germanium catalyst in the finishing stage at temperatures less than 285° C. exhibit low loss of Ge catalyst and excellent low acetaldehyde generating characteristics.

Abstract: Method of changing from a polymerization using a first catalyst to a polymerization using a second catalyst which is incompatible with the first catalyst in a gas-phase reactor, which comprises the steps a) stopping of the polymerization reaction using the first catalyst, b) flushing of the reactor under polymerization conditions with at least one deactivating agent comprising a volatile constituent and a nonvolatile constituent in a weight ratio of from 0.1 to 1000, c) introduction of the second catalyst into the reactor and d) continuation of the polymerization using the second catalyst.

Abstract: A process for preparing a polymer comprising selecting temperatures and amounts of a polymerization medium, a surfactant, a monomer or polymer seed, and any desired additives to achieve an initial temperature in a polymerization reactor; adding the polymerization medium and surfactant as contents to the polymerization reactor whereby the surfactant is added within 1.5 times a time period required for polymerization medium addition; and introducing the monomer or polymer seed and the any desired additives as contents to the polymerization reactor, wherein the temperatures and amounts of the contents are selected such that when the additions are completed, the resulting temperature of the contents of the polymerization reactor is within about 5° C. of a temperature at which polymerization is initiated, and wherein less than about 5 kcal of energy is removed or added per liter of contents in the reactor; and initiating polymerization.

Abstract: A method for continuous ethylene polymerization under high pressure using a polymerization reaction zone comprises a primary reaction zone and a secondary reaction zone wherein the secondary reaction zone has a length of 1.5-6.5 times the length of the primary reaction zone and a cross-sectional area of 1.2-4 times the cross-sectional area of the primary reaction zone. Ethylene is fed continuously into the primary reaction zone at the starting point of the primary reaction zone. Low temperature initiator alone, or an initiator mixture containing mainly low temperature initiator is introduced into the primary reaction zone at the starting point of the primary reaction zone. Initiator alone or an initiator mixture is introduced into the secondary reaction zone at two or more different points of the secondary reaction zone. Ethylene polymer products of various physical properties are produced with high productivity, while the pressure drop is minimized.

Abstract: Disclosed is to provide a process for producing an olefin polymer by continuous polymerization according to which the transition metal compound and the co-catalyst component promptly contact after they are fed to the polymerization reaction tank. The above process for producing an olefin polymer comprises continuously polymerizing an olefinic monomer in the presence of a polymerization catalyst obtained by contact treatment of a transition metal compound and a co-catalyst component in a polymerization reaction tank in which an agitation shaft having an agitating blade is suspended in the central part of the tank.

Abstract: Radical polymerization process for the preparation of halogenated polymers employing one or more ethylenically unsaturated monomers, at least one of which is chosen from halogenated monomers, molecular iodine and one or more radical-generating agents chosen from diazo compounds, peroxides and dialkyl diphenylalkanes Radical polymerization process for the preparation, starting from the halogenated polymers prepared by the process as described above, of block copolymers, at least one block of which is a halogenated polymer block. Halogenated polymers which have a number-average molecular mass Mn of greater than 1.0×104 and an Mz/Mw ratio of less than 1.65. Block copolymers, at least one block of which is a block of halogenated polymer identical to the halogenated polymers described above. Block copolymers comprising at least one halogenated polymer block which have a number-average molecular mass Mn of greater than 1.5×104 and a polydispersity index Mw/Mn of less than 1.60.

Abstract: A process including: heating to a first polymerization temperature a first mixture including a free radical polymerizable monomer, a free radical initiator, and a stable free radical compound to polymerize only a portion of the monomer, resulting in a prepolymer composition; shearing a second mixture including the prepolymer composition, a continuous phase liquid, and a stabilizing compound to create a miniemulsion; and flowing the miniemulsion within a polymerization reactor and heating the miniemulsion at a second polymerization temperature to form polymeric particles wherein the formation of the polymeric particles occurs while the miniemulsion flows within the reactor.

Abstract: There is provided a process for producing a vinyl chloride-based polymer, in which a suspension polymerization of either vinyl chloride monomer, or a mixture of vinyl chloride monomer and another copolymerizable monomer, is conducted in a polymerization vessel fitted with a reflux condenser, the process including the steps of: (A) adding to the reaction mixture a high-activity, oil-soluble polymerization initiator, with a 10-hour half life temperature of no more than 40° C. at a concentration of 0.1 mol/L in benzene, for a specified time within a period from the commencement of heat removal using the reflux condenser through to completion of the polymerization, and (B) adding an antioxidant either continuously or intermittently to the reaction mixture at least during the period from the commencement of addition of the high-activity, oil-soluble polymerization initiator through to completion of that addition.

Abstract: Radical polymerization process for the preparation of halogenated polymers employing one or more ethylenically unsaturated monomers, at least one of which is chosen from halogenated monomers, molecular iodine and one or more radical-generating agents chosen from diazo compounds, peroxides and dialkyl diphenylalkanes Radical polymerization process for the preparation, starting from the halogenated polymers prepared by the process as described above, of block copolymers, at least one block of which is a halogenated polymer block. Halogenated polymers which have a number-average molecular mass Mn of greater than 1.0×104 and an Mz/Mw ratio of less than 1.65. Block copolymers, at least one block of which is a block of halogenated polymer identical to the halogenated polymers described above. Block copolymers comprising at least one halogenated polymer block which have a number-average molecular mass Mn of greater than 1.5×104 and a polydispersity index Mw/Mn of less than 1.60.

Abstract: Various novel block cationomers comprising polyisobutylene (PIB) and poly(2-dimethylamino)ethyl methacrylate) (PDMAEMA) segments have been synthesized and characterized. The specific targets were various molecular weight diblocks (PDMAEMA+) and triblocks (PDMAEMA+-b-PIB-b-PDMAEMA+) with the PIB blocks in the DPn=50–200?(Mn=3,000–9,000 g/mol) range connected to blocks of PDMAEMA+ cations in the DPn=5–20 range. The overall synthetic strategy for the preparation of these block cationomers comprised four steps: 1) Synthesis by living cationic polymerization of mono- and di-allyltelechelic polyisobutylenes, 2) End group transformation to obtain PIBs fitted with termini capable of mediating the atom transfer radical polymerization (ATRP) of DMAEMA, 3) ATRP of DMAEMA and 4) Quaternization of PDMAEMA to PDMAEMA+I? by CH3I. Kinetic and model experiments provided guidance to develop convenient synthesis methods.

Abstract: The invention relates to a polymerization process wherein at least one peroxide, with a half life in between 1 hour and 0.001 hour at the polymerization temperature at the moment of dosing, is dosed to the reaction mixture at the polymerization temperature and wherein at least during part of the period in which the peroxide is dosed i) the cooling means of the reactor are kept at essentially maximum cooling capacity and ii) the amount of initiator that is dosed is actively controlled such that the desired polymerization temperature is achieved and maintained within 0.3° C. of said polymerization temperature.

Abstract: This invention relates to a process for controlling the architecture of copolymers of at least two unsaturated monomers, made by free-radical polymerization in the presence of a cobalt-containing chain transfer agent, including the control of molecular weight, degree of branching and vinyl end group termination, by varying at least one of the variables of molar ratio of monomers, their relative chain transfer constants, polymerization temperature and degree of conversion and amount of cobalt chain transfer agent; and polymers made thereby.

Abstract: The invention relates to a suspension polymerization process for the preparation of styrene-containing (co)polymers, wherein the process comprises the steps of continuously or semi-continuously dosing an initiator to the reaction mixture, said initiator having a specified half-life at the temperature of the reaction mixture to which it is dosed. The invention further relates to styrene based (co)polymer obtainable by said process, and to the use of said styrene (co)polymer in a shaping process.

Abstract: There is provided a process for producing a vinyl chloride-based polymer, in which a suspension polymerization of either vinyl chloride monomer, or a mixture of vinyl chloride monomer and another copolymerizable monomer, is conducted in a polymerization vessel fitted with a reflux condenser, the process including the steps of: (A) adding to the reaction mixture a high-activity, oil-soluble polymerization initiator, with a 10-hour half life temperature of no more than 40° C. at a concentration of 0.

Abstract: The invention pertains to a process wherein initiators and protective colloids are both metered to a polymerization mixture. This manner of metering allows for improved control of the polymerization rate and an improved reactor space-time yield, and the process will render a polymer with a relatively high porosity.

Abstract: Radical polymerization process for the preparation of halogenated polymers and block copolymers. Halogenated polymers and block copolymers.

Abstract: The present invention relates to a method of producing multimodal polyolefins using at least one or more activated metallocene catalysts. The activated metallocene catalysts are used in combination in a single-process method. The method allows for the production of multimodal polyolefins of tunable composition, molecular weight and polydispersity.

Abstract: A process to support a homogeneous catalyst on a porous solid support is performed in two separate zones. In the first zone the solid is contacted, under stirring, with an amount of a catalyst solution lower than the total pore volume of the solid. In the second zone the solid is dried from the solvent while flowing under pneumatic conveying. A loop circulation of solid is established between the two zones, so that the solid is subject to more contacting steps. The process is particularly suitable to support a metallocene-alumoxane polymerization catalyst on a porous prepolymer. The process can be advantageously performed in continuous, thus fitting the needs of an industrial scale production process.

Abstract: A stable free radical process for preparing a polymer having acid anhydride functionality includes heating a mixture comprised of a stable free radical agent, maleic anhydride or derivative thereof, and at least one polymerizable electron donor monomer to initiate exothermic reaction and during exotherm of the reaction, adding additional amounts of stable free radical agent to control the reaction temperature. The mixture may also include a stable free radical initiator. In the mixture, the maleic anhydride or derivative thereof preferably comprises from about 10% to about 70%, molar basis, of a total amount of the maleic anhydride or derivative thereof and the at least one polymerizable electron donor monomer. Typically, the heating is to a temperature of from about 100° C. to about 160° C., and the rate of addition of the additional amounts of stable free radical agent is adjusted to control the reaction temperature to be about 160° C. or less.

Abstract: Processes for transitioning among polymerization catalyst systems, preferably catalyst systems that are incompatible with each other. In particular, the processes relate to transitioning from olefin polymerizations utilizing metallocene catalyst systems to olefin polymerizations utilizing traditional Ziegler-Natta catalyst systems.

Abstract: Processes for transitioning among polymerization catalyst systems, preferably catalyst systems that are incompatible with each other. In particular, the processes relate to transitioning from olefin polymerizations utilizing metallocene catalyst systems to olefin polymerizations utilizing traditional Ziegler-Natta catalyst systems.

Abstract: The invention provides a hot melt adhesive composition including a tubular reactor copolymer of ethylene and 5 to 20 mol % of comonomer units derived from an alkyl acrylate or alkyl methacrylate, wherein the copolymer has a melt index of at least 300 g/10 min. The alkyl group of the alkyl acrylate or alkyl methacrylate can be a linear or branched C1 to C12 group, particularly n-butyl. If desired, the hot melt adhesive can further include tackifiers, waxes, antioxidants and other desired additives. The hot melt adhesive composition shows improved heat resistance and favorable properties, such as has a shear adhesion fail temperature of at least 80° C., without the need to use high melting waxes. The invention further provides articles such as cartons, cases, trays, bookbindings or disposables including the hot melt adhesive compositions.

Abstract: A curable fluoroelastomer composition for preparing a perfluoroelastomer. The composition includes; (1) a perfluoropolymer having one or more cure-sites selected from a halogen capable of participating in peroxide cure reaction and/or nitrile groups; (2) an organic peroxide and/or a compound capable of effecting curing of the perfluoropolymer through said nitrile groups; and (3) optionally a polyunsaturated coagent. The perfluoropolymer in the composition is essentially free of ionic end groups and the total amount of metal cations in the composition is not more than 10 ?g/g perfluoropolymer. The perfluoroelastomers may be obtained from curing the composition in a sufficiently low amount of metal cations so as to make the fluoroelastomer suitable for use in the semi-conductor industry.

Abstract: Microspheroidal particles, suitable as fluidized bed catalyst supports, are prepared by incorporating a portion of small, preferably recycled, particles into a slurry of inorganic oxide sol and inorganic particles which is spray dried to form microspheroidal particles.

Abstract: A fluoropolymer suitable for the preparation of a fluoroelastomer. The fluoropolymer generally includes repeating units derived from the monomers tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, chlorotrifluoroethylene and optionally one or more repeating units from fluorinated monomers other than tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride and chlorotrifluoroethylene.

Abstract: In forming pressure sensitive adhesive microspheres by copolymerizing a non-ionic monomer of an alkyl acrylate or alkyl methacrylate ester of a non-tertiary alcohol and an ionic monomer copolymerizable with said non-ionic monomer, non-free radically polymerizable acid is present during the polymerization to promote formation of solid rather than hollow microspheres and to reduce residual unconverted ionic monomer. These microspheres exhibit reduced adhesive transfer in downstream use as a repositionable pressure sensitive adhesive. A water soluble initiator is optionally added to the polymerization mixture after achieving about 90% conversion of the non-ionic monomer to further reduce residual unconverted ionic monomer.

Abstract: Process for the production of statistic elastomeric conjugated diene-vinyl arene copolymers having a branched structure which comprises: (1) anionic copolymerization in solution of the conjugated diene and vinyl arene monomers, in the presence of randomizing agents and an initiator selected from the group of Lithium alkyls, the copolymerization being carried out until the almost total disappearance of the monomers; (2) addition to the solution of step (1) of a quantity of Lithium alkyl from 1 to 4 times the molar quantity of the Lithium alkyl of step (1); (3) addition to the polymeric solution of step (2) of a compound having the general formula R—Br, the molar ratio between R—Br and the total Lithium alkyl ranging from 0.6/1 to 1/1, preferably from 0.7/1 to 0.9/1, thus obtaining an elastomeric branched copolymer.

Abstract: This invention relates to processes for transitioning among polymerization catalyst systems, preferably catalyst systems, which are incompatible with each other. Particularly, the invention relates to processes for transitioning among olefin polymerization reactions utilizing Ziegler-Natta catalyst systems, metallocene catalyst systems and chromium-based catalyst systems.

Abstract: Processes for transitioning among polymerization catalyst systems, preferably catalyst systems, which are incompatible with each other. Particularly, processes for transitioning among olefin polymerization reactions utilizing silyl-chromate catalyst systems and metallocene catalyst systems.

Abstract: The present invention is a process for transitioning from a first polymerization catalyst system to a second polymerization catalyst system incompatible with the first polymerization catalyst system in a gas-phase reactor. The novel process comprises conducting a first polymerization reaction using a first polymerization catalyst system; stopping the first polymerization reaction; removing the contents of the first polymerization reaction from the reactor while maintaining a substantially closed system; then, in the substantially closed system, introducing a substantially contaminant free seedbed into the reactor; introducing a second feed system and a second catalyst system into the reactor; and conducting a second polymerization reaction.

Abstract: A method of transitioning catalysts for polyolefin polymerization is provided. In one aspect, the process includes providing a polymerization reactor that includes a first catalyst system, contacting olefin monomers with the first catalyst system to form polyolefin in a first polymerization reaction and introducing a catalyst killer to the polymerization reactor in an amount sufficient to terminate the first polymerization reaction. The method further includes introducing a second catalyst system to the polymerization reactor in the presence of at least a portion of the catalyst killer, wherein the at least a portion of the catalyst killer is an amount sufficient to activate the second catalyst system and contacting olefin monomers with the second catalyst system to form polyolefin in a second polymerization reaction.

Abstract: A process of transitioning from a first polymerization reaction conducted in the presence of a mixed catalyst system to a second polymerization reaction conducted in the presence of a chrome-based catalyst system is disclosed, the polymerization reactions being conducted in one embodiment in a polymerization zone of a gas phase fluidized bed reactor which contains a fluidized bed of polymer particles by the essentially continuous passage of monomer gases through the polymerization zone, comprising: a) discontinuing the introduction of the mixed catalyst system into the reactor; b) maintaining polymerization conditions in the reactor and permitting polymerization to continue for a period of time to allow the components of the mixed catalyst system present in the reactor to produce additional polymer particles; c) introducing a deactivating agent into the fluidized bed in an amount sufficient to deactivate the mixed catalyst system; d) establishing optimal conditions within the reactor for the chrome-based

Abstract: This invention relates to a process of polymerizing ethylene in a reactor comprising contacting a catalyst system comprising a supported chromium catalyst and an aluminum alkyl cocatalyst, where the catalyst and cocatalyst are contacted by cofeeding the catalyst and cocatalyst to the reactor or feeding the catalyst and cocatalyst separately to the reactor, where the catalyst and cocatalyst are not contacted prior to the step of feeding or cofeeding, with ethylene, and from 0 to 50 mole % of one or more comonomers, where the polymerization occurs at a temperature between 50 and 120° C., and the molar ratio of aluminum from the cocatalyst to the chromium in the supported chromium catalyst is 30:1 or more.

Abstract: A process of transitioning from a first polymerization reaction conducted in the presence of a mixed catalyst system comprising to a second polymerization reaction conducted in the presence of a chrome-based catalyst system is disclosed, the polymerization reactions being conducted in one embodiment in a polymerization zone of a gas phase fluidized bed reactor which contains a fluidized bed of polymer particles by the essentially continuous passage of monomer gases through the polymerization zone, comprising:

Abstract: A low-molecular (meth)acrylic acid (salt)-based polymer having a good color tone is obtained by polymerizing an aqueous solution of at least one monomer component of a high concentration in the presence of an alkaline substance, wherein: 100 to 95 mol % of the at least one monomer component is a monoethylenically unsaturated monocarboxylic acid (salt) monomer (a) having 3 to 6 carbon atoms; and 0 to 5 mol % of the at least one monomer component is a monoethylenically unsaturated monomer (b) copolymerizable with the monomer (a) (wherein the total of (a) and (b) is 100 mol % ); and wherein: a persulfate salt and hydrogen peroxide are used together as polymerization catalysts; and the entirety of the alkaline substance as used is set not to be more than 99 mol % of the amount which is necessary for neutralizing all acid groups of the at least one monomer component; and wherein: the dropwise addition of the hydrogen peroxide is completed at the latest 10 minutes earlier than the completion time of the dropwise ad

Abstract: A process including: heating to a first polymerization temperature a first mixture composed of a first free radical polymerizable monomer, a first free radical initiator, and a first stable free radical compound to polymerize only a portion of the first monomer, resulting in a prepolymer composition; shearing a second mixture including the prepolymer composition, a continuous phase liquid, and a stabilizing compound to create a miniemulsion; and heating to a second polymerization temperature the miniemulsion to form polymeric particles, wherein there is added to the second mixture, the miniemulsion, or both the second mixture and the miniemulsion at any time prior to the formation of the polymeric particles a second free radical initiator, a second free radical polymerizable monomer, and an optional second stable free radical compound, wherein at least one of the second initiator and the second monomer includes a functional group, wherein the polymeric particles each includes a compound with the functional

Abstract: The invention provides a process for preparing an aqueous polymer dispersion of a copolymer CP of at least two different monomers M1 and M2 by free-radical aqueous emulsion polymerization of the monomers M in the presence of at least one initiator, at least 80% of the monomers M and at least 75% of the initiator being supplied continuously to the polymerization reaction during its course, which comprises changing the rate at which the initiator is supplied to the polymerization reaction a number of times, or continuously, during the polymerization reaction. The invention further provides the polymer dispersions obtainable by this process, polymer powders prepared therefrom, and for the use of the dispersions and/or of the polymer powders to prepare pressure sensitive adhesives.

Abstract: The present invention relates to a nozzle for the injection of a liquid under pressure (3), comprising a vertical feed pipe (1) surmounted by a hollow head (3), the liquid under pressure being conducted between the outer wall (4) of the vertical feed pipe (1) and an inner tube (5), the upper part of the nozzle comprising at least one lateral orifice (6) for expelling the liquid under pressure (3).

Abstract: Disclosed are thermoplastic elastomeric compositions comprising: ps

Abstract: This invention relates to a process for controlling the architecture of copolymers of at least two unsaturated monomers, made by free-radical polymerization in the presence of a cobalt-containing chain transfer agent, including the control of molecular weight, degree of branching and vinyl end group termination, by varying at least one of the variables of molar ratio of monomers, their relative chain transfer constants, polymerization temperature and degree of conversion and amount of cobalt chain transfer agent; and polymers made thereby.

Abstract: The invention concerns a method for preparing stable (co)polymer dispersions in a polyol by polymerising in situ a monomer or a mixture of ethylenically unsaturated monomers, in the presence of one or several azocarboxylic acid ester(s).

Abstract: The invention relates to a polyphenylene ether resin containing residual aliphatic unsaturation as well as composites, blends, and articles made from the polyphenylene ether resin containing residual aliphatic unsaturation. Also included are reaction products between the polyphenylene ether resin containing residual aliphatic unsaturation and other resins and unsaturated resin formulations, e.g., thermosetting polyesters, acrylics, bismaleiimides, silicones, and allylics, and thermoplastics such as polyolefins, styrenics, rubbers, etc.

Abstract: This invention relates to a process for controlling the architecture of copolymers of at least two unsaturated monomers, made by free-radical polymerization in the presence of a cobalt-containing chain transfer agent, including the control of molecular weight, degree of branching and vinyl end group termination, by varying at least one of the variables of molar ratio of monomers, their relative chain transfer constants, polymerization temperature and degree of conversion and amount of cobalt chain transfer agent; and polymers made thereby.

Abstract: This invention relates to a method to start up an olefin polymerization process comprising: a. calculating a trajectory, from elements including catalyst deactivation rate constants (kd), for the rate of introduction of a catalyst system, into a reactor, said catalyst system comprising two different metal catalyst compounds (A and B) and at least one activator, wherein the ratio of the deactivation constants of the two different metal catalyst compounds kdA/kdB is not 1; and b. introducing olefin monomer, a catalyst system, optional co-monomer, and optional chain transfer or termination agents into a polymerization reactor in a manner such that the catalyst system introduction rate is manipulated to follow the trajectory until a desired production rate is achieved.