Modeling and experimental studies of aqueous suspension polymerization processes. 1. Modeling and simulations

1993 ◽  
Vol 32 (9) ◽  
pp. 1822-1830 ◽  
Author(s):  
George Kalfas ◽  
W. Harmon Ray
2011 ◽  
Vol 393-395 ◽  
pp. 1591-1594
Author(s):  
Feng Xia Qiao ◽  
Hong Yuan Yan

The novel pseudo imprinted microspheres were synthesized by aqueous suspension polymerization using theophylline as the template and employed as a special sorbent of solid-phase extraction for selective extraction of acyclovir from swine tissue. The pseudo imprinted microspheres revealed high affinity and selectivity to acyclovir, and the matrix interferences could be efficiently eliminated, which make the extract of solid-phase extraction clean enough for HPLC analysis. The parameters that affect the extraction efficiency of solid-phase extraction were investigated, including solvent of extraction, volume of loading sample, washing and elution solvent, etc. Good linearity was obtained in a range of 0.05~15 μg/mL with correlation coefficient (r2) of 0.9991. The recoveries at three spiked levels were ranged from 91.4% to101.0% with RSD less than of 5.0%.


2021 ◽  
Vol 04 ◽  
Author(s):  
Mariaugusta F. Mota ◽  
Thainá Araruna ◽  
Nathália M. Campelo ◽  
Meiry Gláucia F. Rodrigues ◽  
Gabriella R. Ferreira ◽  
...  

Background: This work presents the preparation and characterization of the polymeric nanocomposites based on methyl methacrylate (MMA), ethyl acrylate (EA), and natural and modified clays. The clays used to prepare the composite were natural green bentonite (GBC-N) and organophilic clays modified with ammonium quaternary salts: Praepagen (GCBP), Dodigen (GCB-D) and Praepagen/Dodigen mixture 1:1 in weight (GCB-P/D). Objective: The experimental studies focused on the evaluation of the effect of clays (in natura and chemically modified) on the final quality of the polymeric nanocomposites containing around 3 wt%. of clay nanocharges in association with MMA to produce poly(methyl methacrylate)/clays; and MMA/EA to form poly(methyl methacrylate-co-ethyl acrylate)/clays. Materials and Methods: The poly(methyl methacrylate)/clay and poly(methyl methacrylate-co-ethyl acrylate)/clay materials were synthesized through mass-suspension polymerization process. The natural and modified green bentonite clays were characterized by X-ray powder diffraction (XRD), infrared spectroscopy (IR), Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) analyzes to understand its effect on the basal spacing, d001 (compared to the pure clay), as a result of cation exchange step, in which also improved the thermal efficiency of the final nanocomposites. Results: The proper incorporation of MMA and MMA/AE monomers between the layers of natural and modified clays occurred through in situ mass-suspension polymerization, leading to a successful exfoliation of clay layers during the growth of the polymer chains. Conclusion: The IR, SEM, TGA and DSC analyzes confirmed the improvement in the thermal property of the composites compared to polymers formed in the absence of clays. The experimental results are very promising, indicating that the experimental protocol based on the in situ formation of polymer nanocomposites by the using sequential mass-suspension polymerization consist of an interesting tool.


2015 ◽  
Vol 1120-1121 ◽  
pp. 615-619
Author(s):  
Hui Yu Jiang ◽  
Mei Hua Zhou ◽  
Ding Pan

Acrylonitrile (AN) and itaconic acid (IA) were used to synthesize UHMWPAN by aqueous suspension method with 2,2’-azobisisobutyronitrile (AIBN) as the initiator and polyvinylalcohol (PVA) as the disperser at different temperatures (55°C~75°C) for different timings (1.0h~3.0h). The usage amounts of AN, IA, AIBN and PVA were also technical polymerization parameters used to obtain the optimal polymerization process. We found that the conversion and the viscosity average molecular weight both achieved the optimum levels when the conditions were as follows: the total monomer concentration (21wt%), the monomer ratio (AN: IA=98:2), the usage amount of the initiator (AIBN, 0.01wt%), the usage amount of the disperser (PVA, 0.1wt%), the polymerization temperature (70°C) and the polymerization time (2h).


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