Continuous polymerization of methyl methacrylate in a taylor-couette reactor. I. Influence of fluid dynamics on monomer conversion

2012 ◽  
Vol 53 (1) ◽  
pp. 96-104 ◽  
Author(s):  
Zhen Liu ◽  
Tao Jin ◽  
Matthias Kind
2021 ◽  
Author(s):  
Narges Ghadi

A mathematical model was developed to simulate emulsion polymerization in batch, semi-batch and continuous reactors for monomers with high water solubility and significant desorption such as vinyl acetate. The effects of operating conditions such as initiator and emulsifier concentration as well as reactor temperature have been studied. The simulation results revealed the sensitivity of polymer properties and monomer conversion to variation of these operating conditions. Furthermore, the impact of monomer soluble impurities on reduction of monomer conversion has been investigated. In order to control polymer molecular weight, application of chain transfer agents such as t-nonyl mercaptan was suggested. Generally, the simulation results fitted well [with] experimental data from the literature. Several optimizing policies were considered to enhance the reaction operation for better product quality. During continuous polymerization, the reactor demonstrates oscillatory behavior throughout the operation. A new reactor train configuration was consistent with the aim of damping the oscillations and producing high-quality latex.


2021 ◽  
Author(s):  
Baranitharan Sanmuga Sundaram

Optimal control policies are determined for the free radical polymerization of three different polymerization processes, in a non-isothermal batch reactor as follows: (1) bulk polymerization of n-butyl methacrylate; (2) solution polymerization of methyl methacrylate with monofunctional initiator; (3) solution polymerization of methyl methacrylate with bifunctional initiator. Four different optimal control objectives are realized for the above three processes. The objectives are: (i) maximization of monomer conversion in a specified operation time, (ii) minimization of operation time for a specified, final monomer conversation, (iii) maximization of monomer conversion for a specified, final number average polymer molecular weight, and (iv) maximization of monomer conversion for a specified, final weight average polymer molecular weight. The realization of these objectives is expected to be very useful for the batch production of polymers. To realize the above four different optimal control objectives, a genetic algorithms-based optimal control method is applied, and the temperature of heat exchange fluid inside reactor jacket is used as a control function. Necessary equations are provided in the above three processes to suitably transform the process model in the range of a specified variable other than time, and to evaluate the elements of Jacobian to help in the accurate solution of the process model. The results of this optimal control application reveal considerable improvements in the performance of the batch polymerization processes.


2011 ◽  
Vol 250-253 ◽  
pp. 804-808
Author(s):  
Ri Qing Chen ◽  
Fu Xiang Chu ◽  
Chun Peng Wang ◽  
Elodie Bourgeat-Lami ◽  
Muriel Lansalot

Ethyl cellulose was hybridized with methyl methacrylate and butyl acrylate via mini-polymerization. The polymerization process was traced to obtain a stable reaction system. The effects of the EC content and viscosity on the monomer droplet size, the particle size and the monomer conversion were investigated. It was showed that the stability of the latex dispersion was strongly dependent of the EC content and viscosity. With investigation on ethyl cellulose series, initiator and crosslinker, the stable mini-emulsion with 10% ethyl cellulose was obtained under conditions of crosslinker and LPO as initiator.


2002 ◽  
Vol 55 (7) ◽  
pp. 475 ◽  
Author(s):  
M. Buback ◽  
A. Feldermann

Copolymerization termination rate coefficients (kt) of the methyl methacrylate–dodecyl acrylate (MMA–DA) and dodecyl methacrylate–methyl acrylate (DMA–MA) systems at 40°C and 1000 bar have been measured using the single pulse (SP)–pulsed laser polymerization (PLP) technique. Plateau regions of kt are observed in the initial polymerization period. The region of constant kt increases with the size of the alkyl ester group, e.g. it extends up to at least 60% monomer conversion in DA and DMA homopolymerizations. The plateau kt values of MA and MMA are significantly above the corresponding DA and DMA values. The kt penultimate unit effect model, which uses the so-called geometric mean approximation, is well suited for representation of the dependence on monomer composition of the plateau kt values. The dependence of kt on monomer composition is quite different at low and at high degrees of monomer conversion. The reason behind this is seen in different types of diffusion control being operative at low and at high degrees of monomer conversion. The plateau-type behaviour is assigned to segmental diffusion control, whereas high-conversion kt is controlled by reaction diffusion.


2011 ◽  
Vol 302 (1) ◽  
pp. 169-178 ◽  
Author(s):  
Zhen Liu ◽  
Roland Kádár ◽  
Matthias Kind

2014 ◽  
Vol 809-810 ◽  
pp. 161-168 ◽  
Author(s):  
Jian Hua Zhou ◽  
Lin Ben Wang ◽  
Yan Jiao Cui ◽  
Jian Zhong Ma ◽  
Gen Xing Sun

Nano-TiO2Modified Fluorine-Containing Polyacrylate Soap-Free Emulsion was Successfully Synthesized via Soap-Free Emulsion Polymerization Technique, in which the Polymerization Monomers Consisted of Methyl Methacrylate (MMA), Butyl Acrylate (BA) and Dodecafluoroheptyl Methacrylate (DFMA). the Influence of Amount of Initiator, Emulsifier, Containing Fluorine Monomer and nano-TiO2on the Performance of Emulsion was Investigated. the Results Showed that the Good Polymerization Stability, and High Monomer Conversion were Obtained when the Amount of Ammonium Initiator was 1.2%, the Amount of Reactive Emulsifier was 3.5%. with Increasing Amount of DFMA, the Monomer Conversion Decreased and the Gel Rate Increased Gradually with the Increase of DFMA Amount. UV-Blocking Ability of the Cotton Fabric Treated with the Hybrid Emulsion Containing Nano-Tio2increased with Increasing Amount of Nano-TiO2. IR Spectrum Results Showed that Nano-TiO2and Fluorine-Containing Monomer were Successfully Introduced in the Segmental Structure of the Polymer. SEM Revealed that Nano-TiO2was Loaded on the Surface of the Treated Cotton Fabric which had Good Hydrophobicity.


2016 ◽  
Vol 11 (3) ◽  
pp. 185-196
Author(s):  
Woon Phui Law ◽  
Wan Hanisah Wan Ibrahim ◽  
Jolius Gimbun

Abstract This paper presents a modeling of methyl methacrylate (MMA) polymerization with toluene in the presence of azo-bi’s-isobutyronitrile (AIBN) using MATLAB. This work aims to optimize the initial concentration of initiator and the reactor temperature to achieve a maximum monomer conversion in minimum batch time. The optimization of solution polymerization of MMA based on the three-stage polymerization model (TSPM) was performed using ode23t solver. The non-linear polymerization kinetics considered the gel, glass and cage effect to obtain a realistic prediction. The predicted reactor and jacket temperature showed a reasonable agreement with the experimental data, where the error is about 2.7 % and 2.3 %, respectively. The results showed that a maximum monomer conversion of 94 % was achieved at 0.126 kgmol m–3 of the initial concentration of AIBN and 346 K of the initial reactor temperature in 8,951 s (2.5 h).


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