Calorimetric and diffractometric study of the room-temperature transitions of polytetrafluoroethylene from aqueous suspension polymerization

1993 ◽  
Vol 271 (7) ◽  
pp. 652-656 ◽  
Author(s):  
V. Villani ◽  
R. Pucciariello
Keyword(s):  
Room Temperature ◽  
Suspension Polymerization ◽  
Aqueous Suspension ◽  
Diffractometric Study

Validation of the Pseudo Imprinted Microspheres for Solid-Phase Extraction of Acyclovir from Swine Tissue

2011 ◽  
Vol 393-395 ◽  
pp. 1591-1594
Author(s):  
Feng Xia Qiao ◽  
Hong Yuan Yan
Keyword(s):  
Solid Phase Extraction ◽  
Solid Phase ◽  
Suspension Polymerization ◽  
Aqueous Suspension ◽  
Selective Extraction ◽  
Phase Extraction ◽  
Matrix Interferences ◽  
The Matrix ◽  
Extraction Volume ◽  
Swine Tissue

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%.

Synthesis of Ultra-High Molecular Weight Polyacrylonitrile (UHMWPAN) by Aqueous Suspension Polymerization

2015 ◽  
Vol 1120-1121 ◽  
pp. 615-619
Author(s):  
Hui Yu Jiang ◽  
Mei Hua Zhou ◽  
Ding Pan
Keyword(s):  
Molecular Weight ◽  
Suspension Polymerization ◽  
Aqueous Suspension ◽  
Average Molecular Weight ◽  
Monomer Concentration ◽  
Polymerization Process ◽  
Polymerization Temperature ◽  
Different Temperatures ◽  
Total Monomer Concentration ◽  
Ultra High Molecular Weight

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).

scholarly journals Magnetic Properties and Biological Activity Evaluation of Iron Oxide Nanoparticles

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Alina Mihaela Prodan ◽  
Simona Liliana Iconaru ◽  
Carmen Mariana Chifiriuc ◽  
Coralia Bleotu ◽  
Carmen Steluta Ciobanu ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Iron Oxide ◽  
Iron Oxide Nanoparticles ◽  
Room Temperature ◽  
Aqueous Suspension ◽  
Hysteresis Loops ◽  
Biological Properties ◽  
Oxide Nanoparticles ◽  
Metallic Ions ◽  
Tem Analysis

The aim of this study was to provide information about the biological properties of iron oxide nanoparticles (IO-NPs) obtained in an aqueous suspension. The IO-NPs were characterized by transmission electron microscopy (TEM). Analysis of hysteresis loops data at room temperature for magnetic IO-NPs sample indicated that the IO-NPs were superparamagnetic at room temperature. The calculated saturation magnetization for magnetic iron oxide wasMs= 18.1 emu/g. The antimicrobial activity of the obtained PMC-NPs was tested against Gram-negative (Pseudomonas aeruginosa1397,Escherichia coliATCC 25922), Gram-positive (Enterococcus faecalisATCC 29212,Bacillus subtilisIC 12488) bacterial as well as fungal (Candida krusei963) strains. The obtained results suggested that the antimicrobial activity of IO-NPs is dependent on the metallic ions concentrations and on the microbial growth state, either planktonic or adherent. The obtained IO-NPs exhibited no cytotoxic effect on HeLa cells at the active antimicrobial concentrations.

Microwave-assisted oxidative coupling of thiols using polystyrene supported bromoderivatives of 2-oxazolidone

2021 ◽  
pp. 096739112110486
Author(s):  
Anjaly Mathew ◽  
Beena Mathew ◽  
Ebey P Koshy
Keyword(s):  
Oxidative Coupling ◽  
Suspension Polymerization ◽  
Aqueous Suspension ◽  
Glycol Diacrylate ◽  
Polymeric Reagent ◽  
Solution Phase Synthesis ◽  
Polystyrene Support ◽  
Polymer Supported ◽  
Normal Laboratory Condition ◽  
Work Up

Polymer-supported reagents have become popular in synthetic organic chemistry over the past decades. But the kinetics of polymer-supported reactions is slow compared to solution phase synthesis because of the poor diffusion of the reactants through the macromolecular polymer matrix. This difficulty can be reduced to a great extent by performing polymer-supported reactions under microwave (MW) conditions. The present work is focussed on the design and development of an innovative, powerful, MW stable and recyclable polymeric reagent prepared by attaching bromoderivative of 2-oxazolidone into the macromolecular matrix of polystyrene. 3% cross-linked polystyrene was prepared by free radical aqueous suspension polymerization technique using tetra ethylene glycol diacrylate as the cross-linking agent and the resulting beads were functionalized by chloromethylation followed by reaction with 2-oxazolidone. Bromine functionality is introduced into the polymer by treating with bromine in carbon tetrachloride. The synthetic utility of the prepared polymeric reagent was demonstrated by the oxidative coupling of thiols to disulfides under MW irradiation. No over oxidation was observed in this protocol and the utilization of polystyrene support simplifies work up and product isolation. The synthesised polymeric reagent displayed good cyclic stability up to five cycles without any substantial decrease in bromine content and satisfactory storage stability under normal laboratory condition. Moreover this may be the first report that uses MW energy for the oxidation of thiols to disulfides using polymer-supported reagents. [Formula: see text]

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