Preparation and Characterization of Homogeneous Grafted Cellulose in DMAc/LiCl System

2013 ◽  
Vol 312 ◽  
pp. 332-336 ◽  
Author(s):  
Fu Shan Chen ◽  
Zhong Hua Sun
Keyword(s):  
Reaction Time ◽  
Methyl Methacrylate ◽  
Graft Polymerization ◽  
Ammonium Persulfate ◽  
Mass Ratio ◽  
Reaction Conditions ◽  
Grafted Polymer ◽  
Grafting Reaction ◽  
The Media

The homogeneous grafting of methyl methacrylate (MMA) onto cellulose was carried out by using ammonium persulfate as an initiator. DMAc/LiCl was used as the solvent for the dissolution of cellulose and the media for the homogeneous graft polymerization of MMA onto cellulose. The efficient reaction conditions of the grafting reaction were confirmed by weighing methods. The results showed that the efficient reaction conditions were as follows: reaction time, 2h; mass ratio of MMA/cellulose, 1/1(g/g); mass ratio of initiator/cellulose, 6/50 (g/g); and reaction temperature, 80°C. Under these conditions, the GP of homogeneous grafted cellulose can reach 76%. The grafted polymer was characterized by FTIR, SEM and TG-DTA.

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.

scholarly journals Salt-Free Dyeing of Modified Cotton through Graft Polymerization with Highly Enhanced Dye Fixation and Good Strength Properties

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 462 ◽  
Author(s):  
Wei Ma ◽  
Sen Du ◽  
Shumin Yan ◽  
Xiaolin Yu ◽  
Zhongjian Zhang ◽  
...  
Keyword(s):  
Graft Polymerization ◽  
Strength Properties ◽  
Color Fastness ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
X Ray ◽  
Reactive Blue 19 ◽  
Grafting Reaction ◽  
Dyeing Method ◽  
Reactive Red 195

Modification of cotton fabric with 2-methacryloyloxyethyltrimethyl ammonium chloride (DMC) was achieved through free-radical initiated graft polymerization with K2S2O8/NaHSO3 as the initiator. Grafting of DMC was confirmed by ATR-IR of the modified cotton. The optimal grafting reaction conditions, including DMC dosage, mole ratio of initiator to DMC, temperature, and time, were determined by cation content and dye fixation results of the modified cotton. The modified fibers were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and whiteness measurement. Salt-free dyeing of the modified cotton with commonly used C. I. Reactive Blue 19, C. I. Reactive Yellow 145, and C. I. Reactive Red 195 presented high fixation of 96.8%, 98.7%, and 97.3%, respectively. These results indicated that the modification is effective for changing the surface charge of the fiber and increasing the dye-fiber reactivity. The color fastness and strength property were still very satisfactory. With excellent properties, this dyeing method shows promise in real application for eliminating the usage of salt and reducing environmental pollution.

Preparation and Characterization of PMAA/SiO2 Composite Particle Via Emulsion Polymerization

2012 ◽  
Vol 528 ◽  
pp. 184-187 ◽  
Author(s):  
Ke Hong Zhang ◽  
Jun Juan Du ◽  
Hui Xiao ◽  
Yan Yuan
Keyword(s):  
Acrylic Acid ◽  
Emulsion Polymerization ◽  
Silica Gel ◽  
Graft Polymerization ◽  
Polymer Layer ◽  
Grafted Polymer ◽  
Chemically Modified ◽  
Ft Ir ◽  
Silica Gel Particles

Silica gel particle was chemically modified by using 3-methacryloxypropyl trimethoxysilane (KH-570) as coupling agent. Then poly methyl acrylic acid (PMAA) was grafted on the surface of particles MPS-SiO2 with the method of Emulsion Polymerization, and grafting particles PMMA/SiO2 were prepared. The grafting particle PMAA/SiO2 was characterized by using FT-IR, TG and SEM. The experimental results show that the graft polymerization of methyl acrylic acid (MAA) on onto the surface of silica gel particles can successfully realized using the method of “graft from”. During the graft polymerization, the grafted polymer layer is a hindrance to the subsequent graft polymerization. When the grafted polymer layer reach to a certain density via overlapping and entwisting, a kinetic barrier will be built up. Hence, the grafting degree of the polymer under a certain condition has a limiting value.

Preparation and Characterization of Cationic Cassia Tora Gum

2013 ◽  
Vol 781-784 ◽  
pp. 526-530 ◽  
Author(s):  
Shao Ying Li ◽  
Chun Mei Niu ◽  
Hua Yu Zhong
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Water Solubility ◽  
Cold Water ◽  
Water Solution ◽  
Molar Ratio ◽  
Reaction Conditions ◽  
Cassia Tora ◽  
Dispersing Agent

Series of cationic cassia tora gum (CCTG) were synthesized using 3-chloro-2-hydroxypropyl trimethyl ammonium chloride (CHPTAC) as cationic etherifying agent, isopropanol-water solution as dispersing agent, in presence of sodium hydroxide under different reaction conditions. The optimum ratio for preparing the cationic cassia tora gum are that CHPTAC-CTG molar ratio is 0.6:1; NaOH-CHPTAC molar ratio is 1.3:1.The optimum conditions are that reaction temperature is 55°Cand reaction time is 3.5 h. The cold water solubility was improved apparently. The solution transmittance has corresponding relationship with the nitrogen content (N%) in the certain range, and the maximum transmittance is up to 87.2%. N% increased with the increase of reaction time and stable N% can be obtained in shorter reaction time at higher reaction temperature. The products were characterized by 13C-NMR. The heat resistance of CTG and CCTG were analyzed.

Study on Synthesis of Cationic Water in Water Polyacrylamide Emulsion Strength Agent

2012 ◽  
Vol 581-582 ◽  
pp. 164-167
Author(s):  
Yong Sheng Ma ◽  
Lin Tong Wang ◽  
Xian Hui Sun ◽  
Na Liu ◽  
Guang Li Song
Keyword(s):  
Reaction Time ◽  
Ammonium Persulfate ◽  
Strengthening Effect ◽  
Mass Ratio ◽  
Water Emulsion ◽  
Emulsion Copolymerization ◽  
Sodium Hydrogen ◽  
Cationic Monomer ◽  
Wheat Straw Pulp ◽  
Polymerization Conditions

Emulsion copolymerization of acrylamide (AM) and cationic monomer DMC (methyl acrylacyl oxyethyl trimethyl ammonium chloride) was studied. A series of cationic polyacrylamide (CPAM) emulsion were synthesized using Water in water emulsion polymerization. Influence of polymerization conditions such as cationic monomer (DMC) ratio, reaction time, the initiator dosage on synthetic product strengthening effect to paper pulp was studied. It was showed that the CPAM emulsion optimal synthetic conditions was that AM monomer second adding amount was 60% AM total amount, ammonium persulfate initiator and sodium hydrogen sulfite initiator dosage was 0.138g and 0.03g respectively, mass ratio of DMC and AM was 15:85, reaction time was 7 hours. When the dosage of CPAM emulsion was 1.0% to absolute dry bleached wheat straw pulp, distinct strengthening effect was acquired, tensile index and tearing index of handsheet was increased by 27.2% and 26.8% respectively.

Synthesis and Characterization of Polysulfonyldiphenylene Phenylphosphonate with High Melting Range

2011 ◽  
Vol 396-398 ◽  
pp. 2342-2345
Author(s):  
Zhong Wei Wang ◽  
Hao Dong Duan ◽  
Qing Yu
Keyword(s):  
Thermal Stability ◽  
Reaction Time ◽  
Thermogravimetric Analysis ◽  
Synthesis And Characterization ◽  
Target Product ◽  
High Melting ◽  
Melting Range ◽  
Reaction Conditions ◽  
Good Thermal Stability

Polysulfonyldiphenylene phenylphosphonate (PSPPP) with high melting range of 197 to 205 °C was synthesized via molten polycondensation method. The effect of material ratio, reaction temperature and reaction time of the method was studied, and the preferred reaction conditions were obtained. The target product was characterized by FTIR and thermogravimetric analysis (TGA) was carried out to confirm the thermal stability. The PSPPP synthesized in this paper showed fairly good thermal stability.

The Effects of the Reaction Conditions on the Grafting Degree of SiO2-g-PMAA Particle

2012 ◽  
Vol 581-582 ◽  
pp. 301-304
Author(s):  
Ke Hong Zhang ◽  
Hui Xiao ◽  
Jun Juan Du
Keyword(s):  
Silica Gel ◽  
Reaction Temperature ◽  
Methacrylic Acid ◽  
Graft Polymerization ◽  
Monomer Concentration ◽  
Reaction Conditions ◽  
Grafted Polymer ◽  
Limiting Value ◽  
Methacryloxypropyl Trimethoxysilane ◽  
Grafting Degree

Modified MPS-SiO2 particle was obtained by the bonding of 3-methacryloxypropyl trimethoxysilane (KH-570) on the surface of silica gel particle. The methacrylic acid (MMA) monomers were grafted on the surface of MPS-SiO2 particle to prepare the grafting particles SiO2-g-PMAA. The effects of reaction conditions on the graft degree were explored. The results indicate that the MMA monomers can be easily grafted on the surface of silica gel particle by using the method of graft polymerization. During the graft polymerization, the grafted polymer layer is a hindrance to the subsequent graft polymerization. Then the grafting degree of the polymer under a certain condition has a limiting value. The reaction conditions, such as monomer concentration, the amount of initiator, reaction temperature, have remarkably influence on the graft polymerization of SiO2-g-PMAA.

Study on a High-Temperature Delayed Cross-Linked Acid

2012 ◽  
Vol 624 ◽  
pp. 252-255 ◽  
Author(s):  
Xiao Zhao ◽  
Qi Song ◽  
Hai Lin ◽  
Yan Ling Wang ◽  
Zeng Bao Wang ◽  
...  
Keyword(s):  
Lactic Acid ◽  
High Temperature ◽  
Reaction Time ◽  
Influencing Factors ◽  
Reaction Temperature ◽  
Zirconium Oxychloride ◽  
Cross Linking ◽  
Acid System ◽  
Mass Ratio ◽  
Reaction Conditions

A retarded zirconium cross-linking agent ECA-1 was prepared by using zirconium oxychloride, lactic acid， xylitol, and so on, then we got a high-temperature delayed cross-linking acid with cross-linking agent ECA-1 added to EVA-180 gelling acid, cross-linked acid performance and its influencing factors were discussed in details, such as reaction conditions of crosslinker, concentrations of crosslinker and thickener, and so on. The results showed that the obtained cross-linked acid had good temperature-tolerate and shear-tolerate properties when the mass ratio of zirconium oxychloride, lactic acid and xylitol is 1:1.25:0.0208 , the reaction temperature is 50~55°C, the reaction time is 4 hours, the delayed cross-linking time of acid system can be adjusted by changing the dosage of crosslinker and thickener.

Preparation and Electrospinning of Acidified-Oxidized Potato Starch

2012 ◽  
Vol 535-537 ◽  
pp. 2340-2344 ◽  
Author(s):  
Hong Jie Wang ◽  
Xin Jin ◽  
Wen Yu Wang ◽  
Chang Fa Xiao ◽  
Lin Tong
Keyword(s):  
Reaction Time ◽  
Hydrochloric Acid ◽  
Optimum Condition ◽  
Potato Starch ◽  
Ammonium Persulfate ◽  
Modified Starch ◽  
Oxidizing Agent ◽  
Reaction Conditions ◽  
Native Starch ◽  
Optimum Reaction

This paper investigates the preparation and electrospinning of acidified-oxidized potato starch. In this article, acidified-oxidized potato starch was prepared by adding ammonium persulfate as an oxidizing agent and hydrochloric acid as a catalyst. The effect of reaction time, temperature, the concentration of hydrochloric acid and the content of ammonium persulfate on the viscosity and content of carboxyl were discussed. The optimum reaction conditions were as follows: 1.5 hours ,50°C, 0.5mol/l HCl, 2.5% (NH4)2S2O8. And then, the acidified-oxidized potato starch prepared at the optimum condition was dissolved in dimethyl sulfoxide (DMSO) to be electrospinned by contrast to native starch. Electrospinning of 5wt%-21wt% of modified starch in DMSO produced beads, beaded fibers, and smooth fibers, depending on the concentration range. Smooth fibers were observed until the concentration reached 19wt%, while native starch was 5wt%.

Synthesis and Characterization of Polyacrylic Acid/Xanthan Gum/Bentonite Superabsorbent Polymer

2014 ◽  
Vol 670-671 ◽  
pp. 148-152
Author(s):  
Dan Dan Hou ◽  
Shu Li Ding ◽  
Bo Hui Xu ◽  
Xiao Ran Chen ◽  
Xuan Ye Shen
Keyword(s):  
Polyacrylic Acid ◽  
Xanthan Gum ◽  
Salt Water ◽  
Ammonium Persulfate ◽  
Process Conditions ◽  
Aqueous Environment ◽  
Superabsorbent Polymer ◽  
Mass Ratio ◽  
Ftir Spectral Analysis

A novel polyacrylic acid /xanthan gum/bentonite superabsorbent polymer (SAP) was prepared through chemical crosslinking by a polymerization technique in a complete aqueous environment. This SAP was fabricated effectively by dispersing xanthan gum (XG) and bentonite in a monomeric solution, using N,N’-methylenebisacrylamide as crosslinker and ammonium persulfate as initiator. Fourier transform infrared (FTIR) spectral analysis showed that graft copolymerization reaction took place between acrylic acid (AA), XG and bentonite. The optimal process conditions of preparing SAP were investigated. Results showed that the relevant SAP had maximal salt-water absorption (98g/g) when mass ratio of m (bentonite):m (AA) was 5:1, m (ammonium persulfate):m (AA) was 1.75×10-4, m (N,N’-methylenebisacrylamide):m (AA) was 3×10-4, m (XG) :m (AA) was 1:5, the neutralization degree of AA was 75%. Bentonite can not only effectively increase water absorbency, but also improve water retention ability.

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