continuous polymerization
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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):  
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 ◽  
Vol 8 (1) ◽  
Author(s):  
Ahmad F ◽  
◽  
Hamza Nisar ◽  
Naveed Ahmad ◽  
◽  
...  

The sole objective of this paper is to investigate Simulation and Optimization process for the production of polyethylene terephthalate, the biggest polymer being consumed all over the world. In this way, two polymerization reactors are replaced with one polymerization reactor. In this way equipment and operating and many other cost was reduced. Discussion has also been made on the optimum temperature and pressure along with most suitable catalyst. The objective function for the polymerization reactor is to maximize the production as well as conversion. It is found that the reactor should be operated at a high temperature initially to obtain high conversion of Dimethyl Terephthalate (DMT) first, but then it should be lowered to reduce the formation of side products. Previous work was done on Simulation for the batch reactor only but in this work the Simulation was applied to the continuous polymerization reactor and results is investigated.


KOVALEN ◽  
2020 ◽  
Vol 6 (3) ◽  
pp. 165-170
Author(s):  
Rony Pasonang Sihombing ◽  
Robby Sudarman ◽  
Agustinus Ngatin

Substrate combining could be done by using adhesive. In Indonesia, especially industrial field, solvent base adhesives were still being developed. This kind of adhesive was not environmental friendly and not safe handling. Therefore, Polyvinyl Acetate (PVAc) water-based adhesive was prepared as an outcome of this research as one of solution to overcome the problem above. Effect of surfactant concentration on the viscosity was aimed at this research. Semi continuous polymerization with stirring motor rates on 50 – 500 rpm was used (optional).  Pressure of 1 atm, 750C temperature, 5 – 6 hours reaction time for each was used as polymerization operation in this research. Vinyl Acetate Monomer (VAM), partial hydrolysis Polyvinyl Alcohol (PVOH), water, Ammonium Persulfate (APS) were prepared as raw material. NP-10 and NP-06 were non-ionic surfactants which each concentration was varied in this research. Water-based adhesive with NP-06 concentration variation resulting in viscosity from 98 m.Pa for 0.17 %wt concentration to 213 m.Pa for  0.68 %wt concentration. While NP-10 concentration variation resulting viscosity from 143 m.Pa for 0.17 %wt to 321 m.Pa for 0.68 %wt concentration. Therefore, adhesive with NP-10 surfactant concentration variable has a higher viscosity rate than NP-06 ones. Keywords: Water-based adhesive, non-ionic surfactant, adhesive viscosity


Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2454
Author(s):  
Ivan. Y. Skvortsov ◽  
Valery G. Kulichikhin ◽  
Igor I. Ponomarev ◽  
Lydia A. Varfolomeeva ◽  
Mikhail S. Kuzin ◽  
...  

The effect of temperature and storage time at a constant temperature on the stability of poly-(o-aminophenylene)naphthoylenimide solutions in N-methylpyrrolidone has been analyzed using rotational rheometry. A temperature–time window beyond which an irreversible change in the viscoelastic properties of solutions due to cumulative reactions of continuous polymerization and possible intramolecular cyclization has been detected. The influence of polymer concentration and its molecular weight on the rheological properties of solutions determining the choice of methods for their processing into fibers and films has been investigated. The effect of non-solvents (water and ethanol) additives on the rheological properties of solutions and the kinetics of their coagulation has been studied. Dosed addition of non-solvent into the solution promotes a significant increase in the viscoelasticity up to gelation and phase separation. Non-solvent presence in the polymer solutions reduces the activity of the solvent, accelerates the movement of the diffusion front at coagulation, and minimizes the number of macro defects. The combination of parameters under investigation renders it possible for the first time to develop new principles modifying dopes for wet spinning into aqueous or ethanol coagulation bath and finally to obtain a heat- and fire-resistant polynaphthoylenebenzimidazole fibers.


2020 ◽  
Vol 92 (9) ◽  
pp. 1360-1361
Author(s):  
S. Schwarz ◽  
E. Cremer-Bujara ◽  
P. Biessey ◽  
M. Grünewald

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