Zur kinetik der Polykondensation von Terephthalsäure und Ethylenglykol in dünnen Schmelzeschichten

Rafler, G.; Bonatz, E.; Sparing, H.-D.; Otto, B.

doi:10.1002/actp.1987.010380102

Cited by 10 publications

(9 citation statements)

References 10 publications

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“…In Figure 2.27, the good quality experimental data of Rafler et al [106] for the antimony acetate catalyzed polycondensation under vacuum are shown, demonstrating the dependency of the overall polycondensation rate on the polymer film thickness.…”

Section: Diffusion and Mass Transfer In Melt-phase Polycondensationmentioning

confidence: 75%

“…Currently, the accepted interpretation of experimental evidence is that the polycondensation of PET in industrial reactors is dominantly controlled by diffusion of EG in the melt phase [1,6,8,[102][103][104][105][106][107][108][109][110].…”

Section: Diffusion and Mass Transfer In Melt-phase Polycondensationmentioning

confidence: 99%

“…Data for the diffusion coefficient of water are sparse and have mostly been estimated [106]. This dependency is obvious, because the diffusion coefficient is proportional to the reciprocal of the viscosity which increases by four orders of magnitude during polycondensation from approximately 0.001 Pa s (for P n = 3) to 67 Pa s (for P n = 100) at 280 • C. In later work, Rafler et al [103,104,106] abandoned the varying diffusion coefficient and instead added a convective mass-transport term to the material balance of EG and water. Rafler et al showed in an early work [102] that the diffusion coefficient of EG varies with the overall effective polycondensation rate and they proposed a dependency of the diffusion coefficient on the degree of polycondensation.…”

Section: Diffusion Modelsmentioning

confidence: 99%

See 2 more Smart Citations

Poly(Ethylene Terephthalate) Polymerization – Mechanism, Catalysis, Kinetics, Mass Transfer and Reactor Design

Rieckmann

Völker²

2004

Modern Polyesters: Chemistry and Technology of Polyesters and Copolyesters

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Section: Diffusion and Mass Transfer In Melt-phase Polycondensationmentioning

confidence: 75%

Section: Diffusion and Mass Transfer In Melt-phase Polycondensationmentioning

confidence: 99%

Section: Diffusion Modelsmentioning

confidence: 99%

See 1 more Smart Citation

Poly(Ethylene Terephthalate) Polymerization – Mechanism, Catalysis, Kinetics, Mass Transfer and Reactor Design

Rieckmann

Völker²

2004

Modern Polyesters: Chemistry and Technology of Polyesters and Copolyesters

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“…The values of the mass transfer rate constants for the volatile species such as EG, free DEG, and water were set to 0.05 s Ϫ1 . 2,10,12 The reactions in Table IV were taken into consideration in this study. The vapor-liquid equilibrium compositions were computed with the Flory-Huggins model.…”

Section: Table IV Reactions Considered In the Prepolymerization And Pmentioning

confidence: 99%

“…The forward reaction of polycondensation is accelerated if the pressure is kept low, and this brings about a much more effective removal of EG. The values of the mass transfer rate constants for the volatile species such as EG, free DEG, and water were set to 0.05 s −1 2, 10, 12. The reactions in Table IV were taken into consideration in this study.…”

Section: Introductionmentioning

confidence: 99%

Optimal reaction conditions for the minimization of energy consumption and by‐product formation in a poly(ethylene terephthalate) process

Rhee

2002

J of Applied Polymer Sci

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ABSTRACT:We determined the optimal reaction conditions to minimize the energy cost and the quantities of by-products for a poly(ethylene terephthalate) process by using the iterative dynamic programming (IDP) algorithm. Here, we employed a sequence of three reactor models: the semibatch transesterification reactor model, the semibatch prepolymerization reactor model, and the rotating-disc-type polycondensation reactor model. We selectively chose or developed the reactor models by incorporating experimentally verified kinetic models reported in the literature. We established the model for the entire reactor system by connecting the three reactor models in series and by resolving some joint problems arising when different types of reactor models were interconnected. On the basis of the simulation results of the reactor system, we scrutinized the cause and effect between the reaction conditions and the final quality of the polymer product. Here, we set up the optimization strategy by using IDP on the basis of the integrated reactor model, and the process variables with significant influence on the properties of polymer were selected as control variables with the help of a simulation study. With this method, we could refine the reaction conditions at the end of each iteration step by contracting the spectra of control regions, and the iteration process finally stopped when the profile of the optimal trajectory converged. We also took the constraints on the control variables into account to guarantee polymer quality and to suppress side reactions. Constituting six different strategies by setting weighting vectors differently, we examined the differences in optimal trajectories, the trend of optimality, and the quality of the final polymer product. For each of the strategies, we conducted the optimization to examine whether the number-average degree of polymerization approached the desired value.

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Zur Modellierung der Vorpolykondensation carboxylgruppenhaltiger Ethylenglykolterephthalate

Rafler¹,

Sparing²,

Otto³

et al. 1987

Acta Polymerica

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Fur ein mehrparametriges Reaktions-Stofftransport-Modell der Poly(ethy1enterephthalat)-Bildung aus Terephthalsaure und Ethylenglykol wurden durch Polykondensationsversuche in dunner Schicht die Geschwindigkeitskonstanten von Veresterung, Umesterung und Thermolyse bestimmt. Mit diesen mikrokinetischen Konstanten lassen sich dann die Stoffaustauschgeschwindigkeiten von Ethylenglykol und Wasser in zwangsdurchmischten Polykondensationssystemen ermitteln. 0 wodeaupoeanuu npoqeeca npednoaurcondencayuu ~a p 6 o~c m c o d e p w a q u x mepegfimuamoe 3mmenzaurcoa~ MHoronapaMeTpoBoti MonenH 06pa30BaHHH n o n m a~m e~~e p e +~a~~a~a ~1 3 TepeaTaneBoit KHCJIOTH H ~T H J I~H~J I I I -KOJIR, ywTmamqeit npoTeKamqHe p e a~q m EI npoqeccbI MacconepeHoca, c noMoqm ~K C~~~H M~H T O B ~OJIEIKOH-neHcaqm B TOHKOM caoe onpenenem KoHcTaHm CKOPOCTI~ peaxqnt ~T~P M I $ H K~~H H , n e p e a~e p~@~~~a q~a EI TepMoJIEI3a. Ha OCHOBe aTHX MHKPOKkiHeTkNeCKEIX KOHCTaHT BOBMOXHO 0npe.QeJIeHEIe CKOPOCTH npOqt?CCOB MaCCOnepeHOCa 3TAJIeHrJIAKOJIR Pi BOAEI B nOJIHKOH#?HCaqHOHHbIX CEICTeMaX C nPHHYnHTeJIbHbIM nepeMemHBaHEIeM. On the modelling of the prepolycondensation of oligo(ethy1ene terephthalate) with carboxylic groups For a multi-parameter reaction-mass transfer model of the formation of poly(ethy1ene terephthalate) from terephthalic acid and ethylene glycol the constants of chemical reactions were determined by means of experiments in thin layer polycondensation. Based on these microkinetic constants the rate of mass transfer of ethylene glycol and water in polycondensation systems under the conditions of compelled mixing can be estimated.

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Zur kinetik der Polykondensation von Terephthalsäure und Ethylenglykol in dünnen Schmelzeschichten

Cited by 10 publications

References 10 publications

Poly(Ethylene Terephthalate) Polymerization – Mechanism, Catalysis, Kinetics, Mass Transfer and Reactor Design

Poly(Ethylene Terephthalate) Polymerization – Mechanism, Catalysis, Kinetics, Mass Transfer and Reactor Design

Optimal reaction conditions for the minimization of energy consumption and by‐product formation in a poly(ethylene terephthalate) process

Zur Modellierung der Vorpolykondensation carboxylgruppenhaltiger Ethylenglykolterephthalate

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