Graft Copolymers Of Acrylamide Research Articles

Synthesis of Novel Acrylamide Graft Copolymer of Acacia nilotica Gum for the Stabilization of Melatonin Nanoparticles for Improved Therapeutic Effect: Optimization Using (3)2 Factorial Design.

The objective of the present study was to optimize the microwave-assisted synthesis of the acrylamide graft copolymer of Acacia nilotica gum (AM-co-ANG). Furthermore, graft copolymer was used for the formulation of a nanoparticulate system using a novel top to bottom solvent antisolvent technique for the delivery of melatonin. Grafting of ANG was optimized by using 32 factorial design, where concentrations of polymer and monomer (acrylamide) were used as independent variables and swelling index in acidic (0.1 N HCl) and basic (1 N NaOH) pH. Grafted polymers were further used to develop and optimize nanoparticulate system using concentration of the graft copolymer and concentration of drug as independent variables. The size of the nanoformulation and entrapment efficiency were selected as dependent variables. Difference in infrared spectrum and absorbance maxima in the ultraviolet region confirm that grafting has taken place. Porous structure and a higher contact angle confirmed hydrophobic nature of AM-co-ANG as compared with the native polymer. Acrylamide graft copolymers show more swelling in 1 N NaOH as compared with 0.1 N HCl. In vitro toxicity studies in hepatic (HepG2 cell line), brain (SHSY5Y cell line), and skin (HaCaT cell line) cells easily predict that synthesized polymer have no cytotoxicity. The entrapment efficiency ranged from 55.24 ± 1.35% to 73.21 ± 1.83%. A nonlinear correlation was observed between independent and dependent variables, as confirmed by multivariate analysis of variance, surface regression, and the correlation report. The prepared formulations were able to release drug up to 12 h. The regression coefficient easily predicted that most of the formulations followed Baker-Lonsdale drug release kinetics.

Non-invasive drug delivery system for the delivery of protein/peptide using neem gum and its derivatives

The present investigation is continuation of author’s previous work. In previous work, the author was prepared acrylamide grafted copolymer of neem gum and carboxymethylatedneem gum derivatives. Neem gum polysaccharide (NGP) and its derivatives viz. acrylamide grafted neem gum (NGP-g-Am) and carboxymethylated neem gum (CMNGP) were explored as film forming agent for transdermal delivery of protein/peptide drug (albumin). It was observed that films were not prepared at all the concentrations of NGP with a given concentration range. Studies show that film cannot be prepared using CMNGP even at ahigher concentration of polymer (2 % w/v solution). So only acrylamide grafted neem gum based film were prepared and evaluated. Transdermal films were prepared by using solvent casting method. The developed films were evaluated for various parameters such as drug content, folding endurance, thickness, weight variation, surface pH, moisture uptake, in vitro drug release study and ex-vivo permeation study. The films showed more than 300 folding endurance which demonstrated the good mechanical strength of film. It was also observed that after permeation studies small cracks were also formed in the films. Fabricated films were able to deliver drug upto 7 h. Drug release study and drug permeation studies showed that formulations followed zero order and KorsmeyerPepass model of kinetics. It can be concluded from the findings of the results that acrylamide graft copolymers of neem gum were able to deliver protein/peptide drugs through transdermal route.

Removal of Congo red from aqueous solution by adsorption using gum ghatti and acrylamide graft copolymer coated with zero valent iron

Gum ghatti (Gg) and acrylamide (AAm) grafted copolymer [poly (Gg-AAm)] coated by zero valent iron (ZVI) was developed to remove toxic Congo red (CR) from waste water. Prepared composite, [poly (Gg-AAm)/ZVI] was characterized by FESEM, TEM, BET, FTIR and XRD. CR adsorption from water using [poly (Gg-AAm)/ZVI] was investigated and several parameters discussed, such as solution pH, contact time, dosage and temperature to find out removal efficiency of polymer composite. The kinetic data for the adsorption of CR followed the pseudo-second-order model and the Langmuir maximum adsorption capacity for CR at pH 7.0 were found to be 153.8, 200 and 250 mg/g at 25, 35 and 45 °C correspondingly. Desorption studies revealed that prepared composite can be used up to three cycles efficiently and thermodynamic parameters such as Gibbs free energy (ΔG0), enthalpy (ΔH0) and entropy (ΔS0) changes showed the adsorption of CR onto [poly (Gg-AAm)/ZVI] was feasible, spontaneous and endothermic.

Microwave-assisted preparation of biodegradable, hemocompatible, and antimicrobial neem gum–grafted poly (acrylamide) hydrogel using (3)2 factorial design

The objective of the study was to prepare neem gum polysaccharide graft copolymers of acrylamide (NGP-g-Am) using 3 factorial design. Prepared NGP-g-Am’s hydrogels were characterized using UV-visible spectroscopy, FTIR spectral analysis, SEM images, contact angle determination, biodegradability, hemocompatibility, and pH-dependent swelling ability. NGP-g-Am showed more swelling index in all the media like double distilled water, 1 N NaOH, and 0.1 N HCl than native form. Data obtained through soil burial biodegradation studies were showed t90% for neem gum polysaccharide (NGP) and NGP-g-Am (N1), 9 and 28 days, respectively. Findings of the Lee-White test for blood clotting time showed the longest clotting time (15.39 ± 0.53 min) for NGP-g-Am (N5) as compared with that for the uncoated glass surface (2.05 ± 0.93 min). Thrombus formed during studies were found to be significantly more in case of uncoated glass surface as compared with N (0.47 ± 0.23 mg), N1 (0.29 ± 0.08 mg), N2 (0.30 ± 0.13 mg), N5 (0.29 ± 0.11 mg), N7 (0.29 ± 0.07 mg), and N9 (0.28 ± 0.13 mg). Structure-based docking studies predict that binding of ligands to TLR-4 receptors is significantly more responsible for the antimicrobial effect of both NGP and NGP-g-Am.

Microwave Controlled the Green Synthesis of Acrylamide Graft Copolymers of Azadirachita indica Gum for the Wastewater Management

Microwave Controlled the Green Synthesis of Acrylamide Graft Copolymers of Azadirachita indica Gum for the Wastewater Management

Stability facilitation of nanoparticles prepared by ultrasound assisted solvent-antisolvent method: Effect of neem gum, acrylamide grafted neem gum and carboxymethylated neem gum over size, morphology and drug release

In present research, etoricoxib nanoparticles were prepared using newly developed ultrasonication assisted solvent-antisolvent method. Neem gum (NGP) and their semisynthetic derivatives NGP-g-Am (acrylamide graft copolymer of neem gum) and CMNGP (carboxymethylated neem gum) were used to provide stability to drug nanoprecipitates. In this research response surface methodology based on 32 factorial design was utilized to evaluate the effect of two independent variables (concentration of drug and polymer) over size and entrapment efficiency of nanoparticles (dependent variables). When compared with pure drug nanocrystals, polymer stabilized molecular composite nanoparticles were of smaller size and spherical shape. CMNGP stabilized composite nanoparticles shown smaller size hence better performance in terms of solubility and dissolution rate as compared to NGP and NGP-g-Am. As shown by zeta seizer analysis for the same concentration of drug and stabilizer, size of nanoparticles were found in the range of NGP-g-Am > NGP > CMNGP and reverse case was observed for dissolution rate. Contact angle determination easily predict better hydrophilicity of CMNGP than NGP followed by NGP-g-Am. DSC thermogram predict the amorphous nature of CMNGP than NGP and NGP-g-Am. SEM revealed spherical shaped and non-aggregation of nanoparticles. Prepared nanosuspension show no aggregation and Ostwald repining after 45 days when ultrasonicated for 5 s. t90% of optimized formulations of NGP (N9), NGP-g-Am (A8) and CMNGP (C1) was found to be 249.46 min, 296.63 min and 223.39 min and followed 1° order, Higuchi and 1° order kinetics of drug, respectively. Similarity factor analysis predict that release pattern of drug from three different polymer stabilized nanoparticles are significantly differ to each other. Particle size of nanoparticles was studied in presence of solvent and findings showed no change in size after 45 days.

Synthesis and characterization of maleylated cellulose-g-polyacrylamide hydrogel using TiO2 nanoparticles under sunlight

Graft polymerization onto the cellulose is one way to produce semisynthetic copolymers and semiconductors were hardly used as initiators. Maleylated cellulose (MC) with different degree of carboxyl groups was synthesized and degree of carboxyl groups was determined using titration method. Then the graft copolymers of acrylamide (AM) on MC were synthesized by titanium dioxide semiconductor photoinitiator in aqueous suspension under sunlight. The effect of different parameters, such as the degree of carboxyl groups, degassing of atmosphere, reactor type, light source, MC/AM ratio, and initiator concentration, was evaluated in the synthesis of graft copolymers. MC with a high degree of carboxyl groups about 2.8 mmol g−1 was selected for graft photopolymerization. Maximum monomer conversion (55%) for Maleylated cellulose-g-polyacrylamide (MC-g-PAM) was achieved with 0.5 mg TiO2, MC/AM = 0.056, argon atmosphere, sunlight source, and double quartz tube reactor. The maximum amount of equilibrium swelling (41 g g−1) was achieved for MC-g-PAM with 34% monomer conversion. The resulting graft copolymers were characterized by FT-IR, SEM, and TGA. Synthesis of MC-g-PAM using TiO2 nanoparticles (NPs) as the initiator was done successfully that shows the TiO2 NPs are useable in graft polymerization of acrylamide monomers onto the MC under sunlight.

Modification of guar gum through grafting of acrylamide with potassium bromate/thiourea redox initiating system

In the present work, graft copolymers of acrylamide onto guar gum were synthesized by free radical polymerization using potassium bromate/thiourea redox initiating system. The guar gum and guar gum-g-polyacrylamide were characterized by infrared spectroscopy and thermogravimetric analysis. It was found that the guar gum-g-polyacrylamid was thermally more stable than pure guar gum. The grafting ratio, grafting efficiency, add-on, and conversion increased with the concentration of bromate and acrylamide, whereas they decreased with increasing the concentration of guar gum. The grafting ratio and grafting efficiency showed maximum value at the concentration of thiourea and hydrogen ions of 3.2×10-3 mol dm-3 and 4.0×10-3 mol dm-3, respectively, but decreased with further increasing the thiourea and hydrogen ions concentrations. The increase in temperature from 30 to 45 °C resulted in increasing the grafting ratio while decreasing the conversion. The optimum reaction time for the graft copolymerization was found to be 2 h. Compared to the parent guar gum, the graft copolymer showed higher water swelling capacity and metal ion sorption, as well as better flocculant behaviors.

Polyacrylamide-grafted legume starch for wastewater treatment: synthesis and performance comparison

Polyacrylamide as traditional flocculant begins to draw the public awareness because of its non-biodegradable nature which may cause the long-term environmental degradation problems. A new high-efficient flocculant was synthesized by legume starch and acrylamide to satisfy the demand of coalmine wastewater treatment. Grafting acrylamide onto mung bean starch was investigated and the characterizations of elemental analysis, scanning electron microscopy, gel permeation chromatography, Fourier transform infrared, X-ray diffraction, thermogravimetric analysis, differential scanning calorimetry and nuclear magnetic resonance spectrometer were conducted. The characterization results of the new flocculant prove that acrylamide has grafted onto the mung bean starch molecule chains successfully. Experimental results indicate the optimal synthesis parameters of the new flocculant are: mung bean starch 50 g/L (ethanol solvent), acrylamide 100 g/L, ceric ammonium nitrate 12 g/L, gelatinization temperature 70 °C and copolymerization temperature 70 °C. We also measured and evaluated the performance of the new flocculant on wastewater treatment, and the optimal dosage of the new flocculant is 20 mg/L, with a prominent transmittance of 98.1% and turbidity of 7.82. Experimental results have demonstrated the graft copolymer of acrylamide and mung bean starch owns an outstanding flocculation effect than the traditional polyacrylamide and polyaluminum chloride. The new flocculant has a few features such as environmentally friendly, easy to degrade, fasting sedimentation and low cost, which is especially suitable for the occasions of rigorous environmental requirements and is bound to have broad application prospect for coalmine wastewater treatment.

Synthesis of graft copolymers of acrylamide for locust bean gum using microwave energy: swelling behavior, flocculation characteristics and acute toxicity study

The graft copolymer of locust bean gum (LBG) and acrylamide has been synthesized by microwave assisted method using potassium persulphate (KPS) as an initiator in aqueous medium. Different reaction parameters such as time, initiator concentration, monomer concentration, polymer concentration, and microwave power were studied to get maximum graft copolymer. The grafted copolymer was characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and differential scanning calorimetry (DSC). The graft copolymer exhibited pH switching on-off behavior depending on the pH of the external medium. Flocculation capacity of LBG and LBG-graft-polyacrylamide for both coking and non-coking coals has been studied. Results indicated that the graft copolymer exhibited good flocculation properties compared to native polymer. The graft copolymer was non-toxic in the acute toxicity study, since the acute single dose did not cause any toxic signs, or symptoms. All mice treated with the graft copolymer survived beyond the 14 days of observation period.

Effect of Structure of Graft on the Properties of Graft Copolymers of Acrylamide and Surfactant Macromonomers Dilute Aqueous Solutions

Several surfactant macromonomers (SMMxyz) were prepared by using triblock polymers of ethylene oxide (EO) and propylene oxide (PO) (POx–EOy–POz triblock polymer, x: y: z represent the weight ratio of the different blocks). Then graft copolymers of acrylamide and SMMxyz (PAM-g-SMMxyz) were synthesized. The effects of EO/PO mole ratio, length of grafted SMMxyz and the three relative block sizes on the surface activity and thermo-associativity of PAM-g-SMMxyz dilute solutions were studied. The results showed that the surface tension decreased with increasing PO in the graft at 30°C and decreased with the length of the graft when the temperature was higher than the cloud points of the grafted POx–EOy–POz chains, regardless of EO/PO ratio. When the EO/PO ratio was the same in the SMMxyz, the PAM-g-SMMxyz with higher PO content at the graft end had higher surface activity. With increasing temperature, the hydrodynamic radius (Rh) of PAM-g-SMMxyz in dilute aqueous solution increased. The polymer with shorter grafts may have much more intermolecular interaction points and there were more polymer chains in the polymeric aggregates, which led to Rh increasing with decreasing length of graft. In addition, when the EO/PO was not more than 1:1.74, the three relative block sizes had no great influence on the temperature-associativity of PAM-g-SMMxyz. However, for PAM-g-SMM217 and PAM-g-SMM712, the Rh of PAM-g-SMM217 was smaller than PAM-g- SMM712.

Thermo-Associative and Salt-Associative Graft Copolymers of Surfactant Macromonomers and Acrylamide: Synthesis and Solution Properties in Dilute Aqueous Solutions

Three new surfactant macromonomers (SMM) with different ethylene oxide (EO)/propylene oxide (PO) ratios (for SMM1, SMM2, and SMM3, the EO/PO ratios were 1:0.5, 1:0.9, and 1:1.25, respectively) were synthesized by the reaction between PEO-PPO di-block polymers having terminal tertiary amine groups and chloropropene. Graft copolymers of acrylamide and SMM (PAM-g-SMM) were prepared with different SMMs and grafting densities in water, and the products were confirmed by FTIR and elemental analysis. Owing to the strong hydrophobicity of the graft, the PAM-g-SMM3 was not water soluble. However, PAM-g-SMM1 and PAM-g-SMM2 aqueous solutions had good surface activity and their surface tensions were 44.26 and 37.63 mN/m at a concentration of 1000 mg/L, respectively. In general, in diluted graft PAM solutions, the copolymer predominantly formed intrapolymeric associates. The PAM-g-SMM2 was both thermo-associative and salt-associative in dilute solution. For PAM-g-SMM2, when the temperature and salt concentration increased, interpolymeric aggregations were formed.

The Research of the Preparation and Characterization of Selective Flocculant Suitable for Fine Hematite

This paper, a comprehensive analysis of selective flocculation am fine hematite selected based on the combination of soluble starch and the characteristics of acrylamide was prepared soluble starch - grafting of acrylamide polymer flocculant. Conditions of single-factor experiment studied the conditions on the starch - the impact of acrylamide polymerization and to the level of starch graft ratio to measure the various conditions on the polymerization to determine the optimal conditions of each are as follows: initiator using cerium nitrate Ammonium; initiator concentration 0.001moL / L; AM / soluble starch mass ratio of 2:1; reaction time of 2h; the reaction temperature is 60 °C. In terms of single-factor test, designed a four factors and three levels of the orthogonal test, the optimum conditions are: starch and monomer mass ratio of 1:2; initiator concentration of 0.001 mol / L; the reaction temperature is 65 °C; reaction time was 1.5h. Under these conditions, starch and the grafting rate of 153.24. By scanning electron microscopy and infrared spectrum we can see, the namely, the resulting polymer soluble starch and acrylamide graft copolymer. By hematite flocculation test we can see, with flocculants prepared by flocculation, its ability to better than selective flocculation.

Research on the Selective Flocculant of Soluble Starch and Acrylamide Graft Copolymer for Fine Hematite Particle

This paper, a comprehensive analysis of selective flocculation am fine hematite selected based on the combination of soluble starch and the characteristics of acrylamide was prepared soluble starch - grafting of acrylamide polymer flocculant. We can see through selective testing, the preparation of starch - acrylamide graft polymer of pure quartz and pure hematite were produced on the surface adsorption, through the measured absorbance and then converted to the concentration of ways we can see remnants of the graft material in the quartz very small amount of surface adsorption, while in hematite adsorption volumes. By hematite flocculation test we can see, with flocculants prepared by flocculation, its ability to better than selective flocculation modified maize starch and polyacrylamide.

Synthesis and flocculation characteristics of chitosan and its grafted polyacrylamide

AbstractA flocculant based on chitosan was prepared, and its flocculation behavior was studied. The graft copolymer of acrylamide onto chitosan was synthesized using potassium persulfate as an initiator. The effect of reaction conditions, i.e., deacetylation degree of chitosan (CTS), the effect of the concentration, solution pH, and the initial concentration of kaolin on flocculation characteristics of chitosan‐grafted polyacrylamide (CAM), was discussed. The experimental results showed that the higher the deacetylation degree of chitosan, the better the flocculation performance of CAM. The concentration and pH of flocculant solution had a great impact on the flocculation performance. Compared with chitosan, the graft copolymer had a better flocculating effect on the kaolin suspensions. © 2011 Wiley Periodicals, Inc. Adv Polym Techn 31: 292–297, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.20252

Microwave-assisted synthesis and characterization of polyacrylamide grafted co-polymers of Mimosa mucilage

Response surface methodology was applied to optimize the microwave-assisted graft co-polymerization of acrylamide on Mimosa pudica seed mucilage. The effect of variables, microwave power and time of exposure, concentrations of acrylamide, mucilage and ammonium persulfate on grafting efficiency of graft co-polymerization was screened using Plackett–Burman experimental design. The results revealed that the concentration of acrylamide and mucilage are the most significant variables, which were further optimized using, a central composite design. A second-order polynomial equation fitted to the data was used to predict the response in the optimal region. The optimal grafting parameters provided graft co-polymer with grafting efficiency close to the predicted values. The proposed mathematical model is found to be robust and accurate for graft co-polymerization of acrylamide and Mimosa mucilage consistent with goals of maximizing grafting efficiency. The results of FT-IR, DSC, XRD, and SEM studies confirmed the formation of graft co-polymer of acrylamide and Mimosa mucilage.

Study on the Application of Starch Derivatives as the Regulators of Potassium Drilling Fluids Filtration

Derivatives of starch, such as graft copolymer of acrylamide onto starch, carbamoylethylated starch, carbamoylethyl-dihydroxypropylated starch, and dihydroxypropylated starch have been tested for their properties as components of drilling fluids used for clay inhibition and for the regulation of their rheology. The influence of modified starch and their blends with tylose as protective agents in the filtration of drilling fluids, as well as replacement of tylose, by modified starch were investigated. The viscosity, flow limit, filtration, pH, and dispersion as factors of the properties of potassium drilling fluids with the addition of starch derivatives were determined.

The graft copolymerisation of acrylamide onto cellulose using enhanced Fe<sup>2+</sup> / H<sub>2</sub>O<sub>2</sub> redox initiator system

Graft copolymers of acrylamide onto holocellulose derived from cocoa (Theobroma cacao) wood meal have been produced using hydroquinone enhanced Fe2+/H2O2 redox system. The addition of hydroquinone to the redox system affected the effectiveness of the redox system to initiate graft copolymer formation. The effects of time, monomer concentration, initiator concentration, and temperature were studied to determine the optimum condition for graft copolymer formation. Journal of Applied Sciences and Environmental Management Vol. 10(3) 2006: 151-155

1,2-propanediol-cellulose-acrylamide graft copolymers

1,2-Propanediol–cellulose–acrylamide graft copolymers (PCACs) were developed for enhanced oil recovery. They were prepared with acrylamide and 1,2-propanediol (PDO)–cellulose, which was formed through the addition of glycols to cellulose by the Shotten–Baumann reaction between 3-chloro-1,2-propanediol and cellulose. The graft copolymerization was initiated with a redox system between Ce4+ and glycols in cellulose. The infrared spectrum of PDO–cellulose had some characteristic absorption bands around 2960 (νCH) and 1050 cm−1 (νCO) that also appeared for the PDO group and pyranose ring of cellulose, respectively. The rate of Ce4+ consumption by PDO–cellulose was investigated through the calculation of the overall kinetic constant from the slopes of ln(D − DR) versus time (where D is the absorbance and DR is the absorbance of the original polysaccharide solution) The results showed that PDO–cellulose had high reactivity and that there were two mechanisms of oxidation by Ce4+ with PDO–cellulose. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3022–3029, 2004

Novel grafted cellulose-based hydrogels for water technologies

A wide spectrum of reactive networks and graft copolymers of acrylamide and acrylic acid, alone or with some binary monomers, have been synthesized by benzoyl peroxide as an initiator using glutaraldehyde as the crosslinker and have been characterized by water uptake studies. It was observed that these polymers behave as hydrogels and absorb a good amount of water that has no dependence on the amount of polymer incorporated by grafting but rather depends on the nature of the polymer grafted. In a field study on the actual water samples, these polymers were used to treat some natural water systems otherwise rendered non-potable by natural contamination. The water treated with the hydrogels was made potable and usable for agricultural purposes. The characteristics of the natural water and treated water samples were studied and compared. In a single treatment study, it was observed that a high shift in pH and total scavenging of iron was affected by almost all the hydrogels studied.