scholarly journals Optimization of cellulose acrylate and grafted 4-vinylpyridine and 1-vinylimidazole synthesis

2010 ◽  
Vol 64 (6) ◽  
pp. 529-535 ◽  
Author(s):  
Vaso Bojanic
Keyword(s):  
Noble Metals ◽  
Radical Copolymerization ◽  
Nitrogen Atmosphere ◽  
Molar Ratio ◽  
Vinyl Monomers ◽  
Acryloyl Chloride ◽  
Optimal Conditions ◽  
Grafting Reaction ◽  
Elementary Analysis ◽  
Vinyl Group

Optimization of cellulose acrylate synthesis by reaction with sodium cellulosate and acryloyl chloride was carried out. Optimal conditions for conducting the synthesis reaction of cellulose acrylate were as follows: the molar ratio of cellulose/potassium-t-butoxide/acryloyl chloride was 1:3:10 and the optimal reaction time was 10 h. On the basis of elemental analysis with optimal conditions for conducting the reaction of cellulose acrylate, the percentage of substitution of glucose units in cellulose Y = 80.7%, and the degree of substitution of cellulose acrylate DS = 2.4 was determined. The grafting reaction of acrylate vinyl monomers onto cellulose in acetonitrile with initiator azoisobutyronitrile (AIBN) in a nitrogen atmosphere was performed, by mixing for 5 h at acetonitrile boiling temperature. Radical copolymerization of synthesized cellulose acrylate and 4-vinylpyridine, 1-vinylimidazole, 1-vinyl-2-pyrrolidinone and 9-vinylcarbazole, cellulose-poly-4-vinylpyridine (Cell-PVP), cellulose-poly-1- vinylimidazole (Cell-PVIm) and cellulose-poly-1-vinyl-2-pyrrolidinone (Cell-P1V2P) and cellulose-poly-9-vinylcarbazole (Cell-P9VK) were synthesized. Acrylate cellulose and cellulose grafted copolymers were confirmed by IR spectroscopy, based on elementary analysis and the characteristics of grafted copolymers of cellulose were determined. The mass share of grafted copolymers, X, the relationship of derivative parts/cellulose vinyl group, Z, and the degree of grafting copolymers of cellulose (mass%) were determined. In reaction of methyl iodide and cellulose-poly-4-vinylpyridine (Cell-PVP) the cellulose-1-methyl-poly-4-vinylpyridine iodide (Cell-1-Me-PVPJ) was synthesized. Cellulose acrylate and grafted copolymers were obtained with better thermal, electrochemical and ion-emulation properties for bonding of noble metals Au, Pt, Pd from water solutions. The synthesis optimization of cellulose acrylate was applied as a model for the synthesis of grafted lignin copolymers and grafted tannin polymers with vinyl monomers.

Synthesis of Polycarboxylate Superplasticizer with β-Cyclodextrins as Side Chain

2012 ◽  
Vol 455-456 ◽  
pp. 606-611
Author(s):  
Sheng Hua Lv ◽  
Rui Jun Gao ◽  
Di Li
Keyword(s):  
Maleic Anhydride ◽  
Ammonium Persulfate ◽  
Radical Copolymerization ◽  
Molar Ratio ◽  
Side Chain ◽  
Vinyl Monomers ◽  
Feeding Mode ◽  
Molar Ratios ◽  
Polycarboxylate Superplasticizer ◽  
Effect Of Feeding

A new polycarboxylate superplasticizer (NPC) was synthesized by radical copolymerization of maleic anhydride (MAH), sodium methylacryl sulfonate (MAS), allyl polyethylene glycols (APEG), and β-cyclodextrins grafted maleic anhydride (MAH-β-CD) using ammonium persulfate (APS) as initiator. The effect of feeding mode and molar ratio of monomers, contents of MAH-β-CD and reaction temperature on fluidity was discussed. The results show that the excellent properties of NPC were obtained when molar ratios of MAH, MAS, APEG and MAH-β-CD were 2.5: 0.5 : 1 : 0.1 in the presence of 1 mol% APS of all molar of vinyl monomers at 90 °C for 5 h. Meanwhile, the molecular structure was characterized by FTIR spectrum.

scholarly journals Two-Stage Biodiesel Synthesis from Used Cooking Oil with a High Acid Value via an Ultrasound-Assisted Method

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3703
Author(s):  
Ming-Chien Hsiao ◽  
Wei-Ting Lin ◽  
Wei-Cheng Chiu ◽  
Shuhn-Shyurng Hou
Keyword(s):  
Acid Value ◽  
Molar Ratio ◽  
Optimal Conditions ◽  
Two Stage ◽  
Cooking Oil ◽  
High Acid ◽  
Used Cooking Oil ◽  
Biodiesel Synthesis ◽  
Stage Process ◽  
Ultrasound Assisted

In this study, ultrasound was used to accelerate two-stage (esterification–transesterification) catalytic synthesis of biodiesel from used cooking oil, which originally had a high acid value (4.35 mg KOH/g). In the first stage, acid-catalyzed esterification reaction conditions were developed with a 9:1 methanol/oil molar ratio, sulfuric acid dosage at 2 wt %, and a reaction temperature of 60 °C. Under ultrasound irradiation for 40 min, the acid value was effectively decreased from 4.35 to 1.67 mg KOH/g, which was decreased to a sufficient level (<2 mg KOH/g) to avoid the saponification problem for the subsequent transesterification reaction. In the following stage, base-catalyzed transesterification reactions were carried out with a 12:1 methanol/oil molar ratio, a sodium hydroxide dosage of 1 wt %, and a reaction temperature of 65 °C. Under ultrasound-assisted transesterification for 40 min, the conversion rate of biodiesel reached 97.05%, which met the requirement of EN 14214 standard, i.e., 96.5% minimum. In order to evaluate and explore the improvement of the ultrasound-assisted two-stage (esterification–transesterification) process in shortening the reaction time, additional two-stage biodiesel synthesis experiments using the traditional mechanical stirring method under the optimal conditions were further carried out in this study. It was found that, under the same optimal conditions, using the ultrasound-assisted two-stage process, the total reaction time was significantly reduced to only 80 min, which was much shorter than the total time required by the conventional method of 140 min. It is worth noting that compared with the traditional method without ultrasound, the intensification of the ultrasound-assisted two-stage process significantly shortened the total time from 140 min to 80 min, which is a reduction of 42.9%. It was concluded that the ultrasound-assisted two-stage (esterification–transesterification) catalytic process is an effective and time-saving method for synthesizing biodiesel from used cooking oil with a high acid value.

Synthesis and characterization of amphiphilic graft copolymers with hydrophobic poly(α-methylstyrene) backbone and hydrophilic poly(n-vinylpyrrolidone) side chains

e-Polymers ◽  
2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Fatima Zohra Sebba ◽  
Seghier Ould Kada ◽  
Mohamed Benaicha ◽  
Nerjesse Nemiche
Keyword(s):  
Graft Copolymer ◽  
Graft Copolymers ◽  
Radical Copolymerization ◽  
Side Chains ◽  
Free Radical Copolymerization ◽  
Good Efficiency ◽  
Molecular Weights ◽  
Grafting Reaction ◽  
Viscosity Variation ◽  
End Capping

AbstractIn this study, 2-oxopropylmethacrylate-terminated poly(N-vinyl-2- pyrrolidone) is produced by cationic polymerization using HClO4 as an initiator. Termination (end capping) step is accomplished using 2- hydroxypropylmethacrylate (2HPMA) and the polymer product has different chain lengths of molecular weight averages ranging from 672 to 3049 g/mol. The study also synthesised amphipathic graft copolymers having hydrophobic poly(α- methylstyrene) as a backbone chain and hydrophilic poly(N-vinyl-2-pyrrolidone) (PVP) as side chains of various lengths. The copolymer synthesis was accomplished by free radical copolymerization of ω-oxopropylmethacrylate PVP in the presence of α-methyl styrene initiated with benzoyl peroxide. Measurements of the dynamic viscosity of the polymer solution (20% weight of macromonomers in ethanol) show that the viscosity is proportional to the average molecular weights M̅n . However, a reverse behaviour of the viscosity variation with regard to M̅n is observed for graft copolymer samples. The viscosity variation with respect to the graft copolymer mass must be due to steric effects, which are strongly pronounced in grafted copolymer chains. Appearance of the number of side chains attached to poly(α-methylstyrene) backbone reveals that the grafting reaction has occurred with good efficiency.

Synthesis of Poly(acrylamide-Methacrylate)-G-Octylphenyl Polyoxyethylene and its Micellar Behavior in Aqueous Solution

2011 ◽  
Vol 239-242 ◽  
pp. 3337-3341
Author(s):  
Dong Xia Zhang ◽  
Wen Hui Hu ◽  
Fang Ping Wang ◽  
Lin Ke Xue ◽  
Xin Zhen Du
Keyword(s):  
Aqueous Solution ◽  
Graft Copolymer ◽  
Main Chain ◽  
Radical Copolymerization ◽  
Molar Ratio ◽  
Free Radical Copolymerization ◽  
Transmission Electron ◽  
Spherical Micelles ◽  
Acrylamide Monomer ◽  
Poly Acrylamide

An amphiphilic graft copolymer with poly(acrylamide-methacrylate) as a main chain and octylphenyl polyoxyethylene as side chains (P(AM-MA)-g-C8PhEO10) was successfully synthesized via free radical copolymerization. The structure and the composition of the graft copolymer were characterized by FTIR, 1H-NMR and elemental analysis (EA) in detail. The absolute molecular weight of the copolymer is 1.304×106, as determined by static light scattering (SLS). The molar ratio of acrylamide monomer to the macromonomer is 33:1 in the copolymer and 53 C8PhEO10 branch chains attach to a P(AM-MA) backbone. The micellar behavior of P(AM-MA)-g-C8PhEO10 was preliminarily studied by means of surface tension measurements, transmission electron microscope (TEM) in aqueous solution. It was found that the stable spherical micelles with core-shell structure are formed and polymolecular micelles are larger and more compact than monomolecular micelles. In addition, the graft copolymer has favorable thermal stability.

scholarly journals New Grafted Copolymers Carrying Betaine Units Based on Gellan and N-Vinylimidazole as Precursors for Design of Drug Delivery Systems

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5451
Author(s):  
Stefania Racovita ◽  
Nicolae Baranov ◽  
Ana Maria Macsim ◽  
Catalina Lionte ◽  
Corina Cheptea ◽  
...  
Keyword(s):  
Graft Copolymerization ◽  
Polymer Concentration ◽  
Monomer Concentration ◽  
Ammonium Persulfate ◽  
Nitrogen Atmosphere ◽  
Sustained Drug Release ◽  
Reaction Conditions ◽  
Grafted Polymer ◽  
Grafted Copolymer ◽  
Grafting Reaction

New grafted copolymers possessing structural units of 1-vinyl-3-(1-carboxymethyl) imidazolium betaine were obtained by graft copolymerization of N-vinylimidazole onto gellan gum followed by the polymer-analogous reactions on grafted polymer with the highest grafting percentage using sodium chloroacetate as the betainization agent. The grafted copolymers were prepared using ammonium persulfate/N,N,N′,N′ tetramethylethylenediamine in a nitrogen atmosphere. The grafting reaction conditions were optimized by changing one of the following reaction parameters: initiator concentration, monomer concentration, polymer concentration, reaction time or temperature, while the other parameters remained constant. The highest grafting yield was obtained under the following reaction conditions: ci = 0.08 mol/L, cm = 0.8 mol/L, cp = 8 g/L, tr = 4 h and T = 50 °C. The kinetics of the graft copolymerization of N-vinylimidazole onto gellan was discussed and a suitable reaction mechanism was proposed. The evidence of the grafting reaction was confirmed through FTIR spectroscopy, X-ray diffraction, 1H-NMR spectroscopy and scanning electron microscopy. The grafted copolymer with betaine structure was obtained by a nucleophilic substitution reaction where the betainization agent was sodium chloroacetate. Preliminary results prove the ability of the grafted copolymers to bind amphoteric drugs (cefotaxime) and, therefore, the possibility of developing the new sustained drug release systems.

The radical copolymerization of p-diethynylbenzene with vinyl monomers

1972 ◽  
Vol 14 (4) ◽  
pp. 952-957
Author(s):  
A.Kh. Uzbekova ◽  
V.V. Razumovskii
Keyword(s):  
Radical Copolymerization ◽  
Vinyl Monomers

Preparation of Pd/Ag Film on Porous Ceramic Tube by Osmosis Pressure–Assisted Electroless Plating

2011 ◽  
Vol 199-200 ◽  
pp. 426-430
Author(s):  
Bo Quan Jiang ◽  
Jiang Nan Zhang ◽  
Yu De Liu ◽  
Jian Guo Zou
Keyword(s):  
Electroless Plating ◽  
Hydrogen Permeation ◽  
Sucrose Solution ◽  
Porous Ceramic ◽  
Film Surface ◽  
Solution Concentration ◽  
Alloy Film ◽  
Molar Ratio ◽  
Optimal Conditions ◽  
Permeation Properties

The osmosis pressure was introduced to improve the conventional electroless plating process for preparing porous ceramic supported Pd/Ag inorganic composite membrane. The effects of temperature (t), molar ratio of hydrazine to total metal ions(y), molar ratio of silver ions to palladium ions(x), concentrations of ethylene diamine tetraacetic acid (EDTA) and sucrose solution on the metal deposition rate, silver content in alloy film, surface morphology of film and permeation properties of the membrane were investigated and their optimal conditions were determined to be: [MET]=5mM, x = 20%, y = 1, [EDTA] = 40g•L-1, t = 40 °C, pH =11 and sucrose solution concentration of 6 M. Under these optimal conditions, the prepared Pd/Ag alloy film with thickness of 7.9 μm demonstrated good permeation properties with nitrogen free and hydrogen permeation rate of 8.8×10-3m3•m-2•s-1at 0.3 MPa and 473 K.

Synthesis and Characterization of Pd/Ag/SiO2 Nano-Composite Materials

2017 ◽  
Vol 726 ◽  
pp. 204-209 ◽  
Author(s):  
Jing Yang ◽  
Bao Song Li ◽  
Zhi Tong ◽  
Rui Hua Mu
Keyword(s):  
Zeta Potential ◽  
Size Distribution ◽  
Sol Gel ◽  
Linear Structure ◽  
Nitrogen Atmosphere ◽  
Molar Ratio ◽  
Powder Materials ◽  
X Ray Diffraction ◽  
Silica Network

Pd/Ag/SiO2 sols and powder materials were prepared by adding AgNO3 and Pd (NO3)2·2H2O into a methyl-modified silica sol. Tetraethylorthosilicate and methyltriethoxysilane were used as the silica precursor for the sol-gel reaction. The obtained SiO2 sols and powder materials were characterized by sol particle size distribution, zeta potential analysis, UV-Vis spectra, Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) measurement. It was found that most of the particle sizes of the prepared Pd/Ag/SiO2 sols are about 2~10 nm with narrow size distribution. The zeta potential of Pd/Ag/SiO2 sol with Pd/Ag molar ratio of 7.5/2.5 presents the highest value. The FTIR analysis substantiates that the Si-CH3 groups exist in the silica network and the formed Pd/Ag/SiO2 sol particles possess linear structure. XRD characterization indicates that the Pd2+ and Ag+ in the Pd/Ag/SiO2 materials had be reduced to Pd0 and Ag0, respectively, after annealed in a nitrogen atmosphere at 350°C.

A vinylic rotaxane cross-linker for toughened network polymers from the radical polymerization of vinyl monomers

2017 ◽  
Vol 8 (12) ◽  
pp. 1878-1881 ◽  
Author(s):  
J. Sawada ◽  
D. Aoki ◽  
M. Kuzume ◽  
K. Nakazono ◽  
H. Otsuka ◽  
...  
Keyword(s):  
Radical Polymerization ◽  
Vinyl Monomers ◽  
Network Polymers ◽  
Cross Linker ◽  
Vinyl Group

A [2]rotaxane cross-linker with one vinyl group in each component was synthesized as a vinylic cross-linker for highly toughened network polymers.

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