Continuous polymerization of methyl methacrylate in a taylor-couette reactor. II. influence of fluid dynamics on polymer properties

2012 ◽  
Vol 53 (5) ◽  
pp. 950-955 ◽  
Author(s):  
Zhen Liu ◽  
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.


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

AIChE Journal ◽  
2008 ◽  
Vol 54 (12) ◽  
pp. 3160-3170 ◽  
Author(s):  
Sebastian Terrazas-Moreno ◽  
Antonio Flores-Tlacuahuac ◽  
Ignacio E. Grossmann

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.


2008 ◽  
Vol 8 (4) ◽  
pp. 1852-1857 ◽  
Author(s):  
Suzhu Yu ◽  
Yang Kang Juay ◽  
Ming Shyan Young

Multiwall carbon nanotube (CNT) reinforced poly(methyl methacrylate) (PMMA) nanocomposites have been successfully fabricated with melt blending. Two melt blending approaches of batch mixing and continuous extrusion have been used and the properties of the derived nanocomposites have been compared. The interaction of PMMA and CNTs, which is crucial to greatly improve the polymer properties, has been physically enhanced by adding a third party of poly(vinylidene fluoride) (PVDF) compatibilizer. It is found that the electrical threshold for both PMMA/CNT and PMMA/PVDF/CNT nanocomposites lies between 0.5 to 1 wt% of CNTs. The thermal and mechanical properties of the nanocomposites increase with CNTs and they are further increased by the addition of PVDF. For 5 wt% CNT reinforced PMMA/PVDF/CNT nanocomposite, the onset of decomposition temperature is about 17 °C higher and elastic modulus is about 19.5% higher than those of neat PMMA. Rheological study also shows that the CNTs incorporated in the PMMA/PVDF/CNT nanocomposites act as physical cross-linkers.


2009 ◽  
Vol 21 (5) ◽  
pp. 579-595 ◽  
Author(s):  
Yakov S. Vygodskii ◽  
Tat'yana V. Volkova ◽  
Tat'yana L. Batalova ◽  
Olesya N. Zabegaeva ◽  
Elena M. Belavtseva ◽  
...  

New copolymers have been synthesized by anionic or radical photopolymerization of ε-caprolactam or methyl methacrylate (MMA) in the presence of dissolved polyimides bearing hexafluoroisopropylidene, fluorene or other groups. Using diimides as models it was shown that the kinetics of anionic polymerization of ε-caprolactam depends on the nature of spacer between the imide cycles. The mechanical and tribological properties of copolymers, their water absorbance and the microstructure of copolymer films were studied. It was found that upon the selection of polyimide activator it was possible to gain the desirable control over the polymer properties, namely, the gel fraction content, phase composition, compression modulus, notched Izod impact strength, friction coefficient and temperature of frictional contact. The kinetics of radical polymerization of MMA in the presence of polyimide and model diimide has been studied by differential scanning photocalorimetry and infrared spectroscopy. From the results of the reaction kinetics and the study of polymer structures by Fourier transform infrared spectroscopy, nuclear magnetic resonance, size-exclusion chromatography and thermogravimetric analysis it has been established that radical photopolymerization of MMA in the presence of polyimide leads to the formation of copolymers owing to chain transfer reactions and/or chain termination by the relevant condensation polymer. It has been established that the imide cycles play a significant role in the formation of both copolymers with ε-caprolactam and MMA, respectively.


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