Grafting Of Acrylamide Research Articles

Synthesis and characterization of porous tree gum grafted copolymer derived from Prunus cerasifera gum polysaccharide.

Porous grafted copolymer with excellent thermal stability and swelling capacity was synthesized from water soluble Prunus cerasifera gum polysaccharide (PG) and acrylamide (AM). The monosaccharide compositions and the structure of Prunus cerasifera tree gum were detected by a high-performance anion exchange chromatography (HPAEC) system and 1H NMR and 13C NMR, and the obtained PG-AM copolymer was characterized by Fourier transform infrared (FT-IR), scanning electron microscope (SEM), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), respectively. The results indicated that the water soluble polysaccharides obtained from Prunus cerasifera tree gum were mainly composed of l-arabinose (39.78%) and d-galactose (40.59%) with minor amount of xylose, mannose and uronic acids. The maximum percent and the grafting efficiency of grafting acrylamide (AM) onto PG to form PG-AM were obtained by copolymerization between polysaccharide and 3 times (weight) acrylamide with 3 mmol/L potassium persulfate initiator at 50 °C for 1 h. In addition, lots of isolated and conjoint pores were observed in the prepared PG-AM materials, with a diameters distribution between 2 and 10 μm. Compared with PG, the synthesized copolymer PG-AM showed an excellent performance in thermal stability and swelling capacity. The detailed structural characteristic together with excellent thermal stability and swelling properties will benefit efficient utilization of the synthesized copolymer as a precursor for preparation of large-scale environmentally friendly advanced materials with various potential applications.

Anionic reverse microemulsion grafting of acrylamide (AM) on HydroxyEthylCellulose (HEC): Synthesis, characterization and application as new ecofriendly low-cost flocculant

New water-soluble cellulosic derivative based on HEC was successfully elaborated (HECc), and used as anionic coagulant-flocculant of colloidal systems Fe(OH)3 and to remove of heavy metal ions (Cu(II)) from aqueous media. HECc was synthesized in unconventional reverse microemulsion process using water as ecofriendly solvent and as hydrogen transfer agent, where cyclohexane was employed as continuous phase to reduce the hydrophobicity of the medium. The amide groups grafted on HEC main chain were saponified to increase the negative charge density, and then the zeta potential value of HECc derivative reached -45 mV. The proposed structure of HECc was confirmed by FTIR, 1H, 13C NMR and deept-135. The XRD technique was used to study the effect of grafting process on the crystalline order. Moreover, the morphological changes and the elementary composition of the surfaces were studied using scanning electron microscope equipped with EDX. The new HECc coagulant-flocculant showed a high coagulation-flocculation capacity toward Fe(OH)3 colloidal system at 35 μL as added volume of 0.5% flocculant solution. Moreover, the pH values showed an important effect (species distribution) on the coagulation-flocculation mechanism and on the flocculating capacity to remove (Cu (II).

Cassava starch graft copolymer as a novel inhibitor for the corrosion of aluminium in HNO3 solution

Cassava starch graft copolymer (CSGC) was prepared by grafting acryl amide (AA) onto cassava starch (CS). The inhibition effect of CSGC on the corrosion of aluminium in HNO3 solution was studied by weight loss, electrochemical techniques, scanning electron microscope (SEM), atomic force microscope (AFM), contact angle images and X-ray photoelectron spectroscopy (XPS). Quantum chemical calculation and molecular dynamic simulation were performed to theoretically investigate the adsorption mechanism. CSGC is an effective novel inhibitor, and shows higher inhibition efficiency than either CS or AA. The adsorption of CSGC on aluminium surface obeys Langmuir isotherm. CSGC is a mixed-type inhibitor, while mainly retards the anodic corrosion. EIS consists of a large capacitive loop at high frequencies followed by a small inductive one at middle frequencies and the second capacitive loop at low frequency values, and the impedance strengthens with the concentration of CSGC. SEM and AFM confirms the corrosion of aluminium surface is prominently retarded after adding CSGC to the media. Contact angle image suggests that the inhibited aluminium surface is of hydrophobic nature. XPS provides the evidence of the adsorptive inhibitor of CSGC on aluminium surface. Quantum chemical calculation and molecular dynamic simulation can be well theoretically elucidate that CSGC shows higher adsorption and inhibition ability than CS.

New Type of Sodium Alginate-g-acrylamide Polyelectrolyte Obtained by Electron Beam Irradiation: Characterization and Study of Flocculation Efficacy and Heavy Metal Removal Capacity.

The goals of the paper were first the obtainment and characterization of sodium alginate-g-acrylamide polyelectrolytes by electron beam irradiation in the range of 0.5 to 2 kGy, and second, the evaluation of flocculation efficacy and heavy metal removal capacity from aqueous solutions of known concentrations. Based on sodium alginate concentration, two types of grafted polymers were obtained. Physical, chemical, and structural investigations were performed. Flocculation studies under different stirring conditions on 0.5, 0.1 and 0.2% kaolin suspension were done. The removal capacity of Cu2+ and Cr6+ ions was also investigated. The acrylamide grafting ratio on sodium alginate backbone was found up to 2000% for samples containing 1% sodium alginate and up to 500% for samples containing 2% sodium alginate. Transmittances between 98 and 100% were obtained using, in the flocculation studies, polyelectrolytes containing 2% sodium alginate in concentrations of 0.5 and 1 ppm on kaolin suspension of 0.1 wt %. The polymer concentration was found critical for kaolin suspension of 0.05 and 0.1 wt %. Polymers containing 1% sodium alginate were efficient in Cr6+ ion removal, while those containing 2% in Cu2+ ion removal.

PH-responsive poly (xanthan gum-g-acrylamide-g-acrylic acid) hydrogel: Preparation, characterization, and application

Poly (xanthan gum-g-acrylamide-g-acrylic acid) (XGDA) hydrogel was prepared by grafting acrylamide (AM) and partly neutralized acrylic acid (AA) onto xanthan gum (XG) with trimethylolpropane triglycidyl ether as a cross-linking agent. With the introduction of amino and carboxyl groups by AM and AA, the XG molecules were rearranged with better regularity, leading to higher thermal stability and a more porous structure. The resulting hydrogel exhibited excellent performance in Cu (II)-adsorption and possessed sensitivity to external pH stimuli. The adsorption kinetics and adsorption equilibrium were best described by a pseudo-second-order model and Freundlich isotherms, respectively. The thermodynamic parameters indicated that the adsorption is a spontaneous, endothermic, and a process that increases entropy. The maximum equilibrium adsorption capacity of Cu (II) was 130.31 ± 2.97 mg/g. The XGDA can be regenerated and reused in the following adsorption process. This pH-sensitive hydrogel has potential to be used for the uptake of heavy metal ions from aqueous solution.

Investigation of semi-interpenetrated networks gel for water production control in a mature offshore oilfield

Water flooding as the dominant method to improve oil recovery has been widely applied to most oilfields in the world; however, excess water production has become a major problem for reservoirs that have been flooded by water for many years. The objective of this paper is to prepare and evaluate a novel strong gel that can be used to significantly reduce the permeability of the fluid channels resulting from water flooding. We developed a novel fluid diversion agent called CPP gel, which is a semi-interpenetrated networks gel cross-linked by acrylamide grafting onto sodium carboxymethyl cellulose/polyglycol. The paper investigated its applicability with the Bohai offshore oilfield reservoir conditions. The gel properties, including the rheological performance and blocking efficiency, as well as its influencing factors were investigated. The results showed that the CPP had less injection pressure but higher blocking efficiency than conventional polymer gels, and its blocking efficiency was dependent on the gel components, temperature, water salinity, rock permeability and rheological properties. The decrease in the network chain length, the increase in the interactions among molecules and the increase in the uniformity of the overall network structure could contribute to the enhanced blocking mechanisms. [Received: February 7, 2015; Accepted: January 28, 2017]

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

Microwave Assisted Acrylamide Grafting on a Natural Gum Cassia Tora: Characterization and Pharmacokinetic Evaluation of the Formulation Containing Metformin and Sitagliptin in Rats by LC-MS/MS

A vast proportion of synthesis based polymers used to develop matrix drug delivery systems are too some extent harmful to patients who are taking those formulations for shorter and longer duration of time. Long term toxic effect of synthetic polymers can be countered by replacing those with substituted natural polymers. Under influence of microwave dielectric heating natural gums can be modified as promising biodegradable polymeric materials. The grafting as a tool to manipulate natural polysaccharides with the precise control over the features of the grafted polymer, under microwave irradiation can be a powerful strategy for the development of natural polymers with tailor made properties. The grafting of acrylamide onto cassia tora (CT) was carried out using microwave-assisted graft copolymerization and was characterized. The acute oral toxicity study in rodents was carried out according to OECD guideline. The pharmaceutical application in the tablet formulation of the acrylamide grafted CT (best batch) was studied by using metformin and sitagliptin as model drugs. It can be concluded that microwave assisted acrylamide grafting on cassia tora was successful. The developed formulation with the grafted CT as polymer was also studied in rats for pharmacokinetic profiling. The developed bioanalytical method to determine both the drugs in rat plasma was found simple, reproducible and validated as per the guidelines.

Experimental design sequential generation and overall D-efficiency criterion for electron beam grafting of corn starch

An experimental investigation of the electron beam irradiation induced grafting of acrylamide onto corn starch was performed. In this way the synthesis of water-soluble copolymers having flocculation abilities is realized. The acrylamide monomer provides a polar graft side chain which turns it into a hydrophilic copolymer. The robust engineering approach was implemented for the estimation of models for the means and the variances of the investigated quality parameters in production conditions, aiming the assurance of low toxicity of the synthesised copolymer, process economic efficiency, copolymer efficiency in the flocculation process and its good solubility in water. In order to improve the accuracy of the estimated models, performing new experiments was planned, based on the sequentially generated D-optimal designs. An approach for the generation of such designs for several quality parameters is presented.

Synthesis and characterization of a non-cytotoxic and biocompatible acrylamide grafted pullulan – Application in pH responsive controlled drug delivery

The aim of present study was to develop a pH responsive rate controlling polymer by acrylamide grafting onto pullulan. Grafting was performed using free radical induced microwave assisted irradiation technique using ceric ammonium nitrate as free radical inducer. Acrylamide grafted pullulan (Aam-g-pull) was characterized by Fourier transform infrared spectroscopy, solid state 13C nuclear magnetic resonance and field emission scanning electron microscopy. In vitro enzymatic degradation of Aam-g-pull showed degradation of 22.45% after 8 h with degradation rate constant (k) of 0.019 min−1. In vitro cytotoxicity test did not show cell viability below 80% on HepG2 cell line. Pirfenidone tablets were prepared by utilizing wet granulation method using Aam-g-pull as the only rate controlling polymer. The tablets were characterized in terms of in-process quality control parameters like weight variation, hardness, assay, and in vitro dissolution study. The dissolution study showed that the cumulative drug release in phosphate buffer pH 6.8 (rel3 h = 44.12 ± 0.56%) got a significant jump as compared to the release in 0.1 N hydrochloric acid (rel2 h = 26.78 ± 0.23%), confirming the material to be pH responsive. Aam-g-pull can be used as pH responsive rate controlling polymer.

Lignin-g-poly(acrylamide)-g-poly(diallyldimethyl- ammonium chloride): Synthesis, Characterization and Applications.

The search for a renewable substitute to petroleum‐based products has fueled increasing research on lignin, an under‐utilized product from pulping processes. In this work, lignin was copolymerized with acrylamide (AM) and diallyldimethylammonium chloride (DADMAC) under acidic conditions with Na2S2O8 as an initiator, generating a cationic water‐soluble lignin‐g‐P(AM)‐g‐P(DADMAC) copolymer. The optimal reaction conditions, using a 5×4 factorial design experiment, were determined to be an AM/DADMAC/lignin molar ratio of 5.5:2.4:1, 90 °C, 0.26 mol L−1 of lignin, and pH 2. Under the optimal reaction conditions, the resulting lignin‐g‐P(AM)‐g‐P(DADMAC) copolymer was 83 % soluble in an aqueous solution (at 10 g L−1) and at neutral pH. The copolymer had a charge density of 1.27 meq g−1, molecular weight of (1.33±0.08) ×106, an AM grafting ratio of 112 wt %, and a DADMAC grafting ratio of 20 wt %. In addition, the activation energy for producing this copolymer as well as the thermal and rheological properties of the copolymer were determined. The flocculation performance of lignin‐g‐P(AM)‐g‐P(DADMAC) copolymer was evaluated in a kaolin suspension, which showed that the lignin copolymer had a comparable flocculation efficiency with the synthetic analogue of P(AM)‐g‐P(DADMAC) at pH 6.

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.

Microwave Assisted Synthesis of Acrylamide Grafted Locust Bean Gum for Colon Specific Drug Delivery

Microwave Assisted Synthesis of Acrylamide Grafted Locust Bean Gum for Colon Specific Drug Delivery

Binary grafted chitosan film: Synthesis, characterization, antibacterial activity and prospects for food packaging

The antimicrobial binary grafted chitosan film [chit-g-Poly (An-co-Am)] was prepared by grafting of acrylonitrile and acrylamide on to chitosan via microwave initiated graft copolymerization. The grafting of acrylonitrile and acrylamide onto chitosan backbone was confirmed by FTIR, XRD, SEM and TGA/DTA/DTG analytical techniques. The binary grafted chitosan film possessed efficient antimicrobial activity against three tested strains, i.e. Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. The prepared binary grafted chitosan film was tested for packaging apple and guava to prevent microbial infection and extend their shelf life. The biodegradability study of binary grafted chitosan film was also done and all the results were positive.

Sodium dodecyl sulfate intercalated and acrylamide anchored layered double hydroxides: A multifunctional adsorbent for highly efficient removal of Congo red

In this study, a novel adsorbent was designed and synthesized via intercalation of sodium dodecyl sulfate (SDS) in the interlayer, and subsequent grafting of acrylamide (AM) on the layer of layered double hydroxides (LDH) (named as AM/SDS-LDH), and applied for congo red (CR) removal. The morphological structure, wettability and physicochemical properties of the adsorbents were thoroughly characterized using SEM, EDS, N2-adsorption/desorption isotherm, static contact angle, XRD and FTIR. Results elucidated that SDS and AM were successfully introduced into the interlayer and onto the layer of LDH, respectively. Adsorption experimental results suggested that the maximum adsorption capacities of CR on SDS-LDH and AM/SDS-LDH at pH 5.0 and 293 K were 714.29 and 1118.78 mg/g, respectively, which were much higher than that of CR on LDH (588.24 mg/g). Based on the BET, XRD and FTIR analysis, the higher adsorption capacity of AM/SDS-LDH was mainly attributed to high surface area, large basal spacing as well as the abundant NH2 groups. The experimental data can be well fitted by pseudo-second-order kinetic and Langmuir isotherm models. Thermodynamic parameters indicated the adsorption process was favorable under the higher temperature condition. The synergistic effect existed during the adsorption process of CR onto AM/SDS-LDH, including the electrostatic interactions, anion exchange and hydrophobic-hydrophobic interactions. Overall, this study provided a strategy for design and fabrication of highly efficient adsorbents.

Acrylamide grafted chitosan based ion imprinted polymer for the recovery of cadmium from nickel-cadmium battery waste

Spent nickel-cadmium (Ni-Cd) batteries are classified as hazardous waste due to the presence of toxic cadmium (Cd). Sustainable solution to this problem can be adoption of resource recovery methods for the reuse of Cd. This has been attempted in the present work using the biopolymer chitosan having inherent affinity for metals. Stability of chitosan in acidic medium was improved by grafting it with a suitable grafting agent and crosslinking. Further, it was used for the synthesis of acrylamide grafted chitosan based Cd ion imprinted polymer (CdIIP) using Cd as template and epichlorohydrin (EPI) as crosslinker for the selective recovery of Cd. Density functional theory (DFT) confirmed acrylamide as the best grafting agent with ΔG of −17.98 Kcal/mol for the acrylamide grafted chitosan. FTIR confirmed the grafting of acrylamide on chitosan as well as successful synthesis of CdIIP. EPI proved to be a better crosslinking agent as compared to glutaraldehyde (GLA) for CdIIP as confirmed by EDS. Adsorption of Cd on CdIIP was influenced by pH, time, initial Cd concentration and CdIIP dose. The kinetic data fitted well to pseudo-second-order equation than first order with R2 equals to 0.997. The monolayer adsorption capacity for Cd (167 mg/g) calculated using Langmuir isotherm model was in close approximation to the experimental adsorption capacity of 152 ± 3 mg/g. The thermodynamic data confirmed exothermic and spontaneous nature of adsorption. 84.3% of Cd could be recovered by CdIIP from the acidic leachate of the Ni-Cd battery waste. CdIIP could be effectively reused for five cycles.

Nano-modification of polyamide thin film composite reverse osmosis membranes by radiation grafting

Radiation synthesis of reverse osmosis membranes were carried out by grafting of N-Isopropyl acrylamide (NIPAM) and ZnO nanoparticles incorporation onto polyamide thin film composite reverse osmosis membranes PA(TFC). The effect of monomer concentration, radiation time and concentration of ZnO nanoparticles on the grafting percent were investigated. The properties of the prepared grafted reverse osmosis membranes were characterized by using different analytical tools such as contact angles goniometer, Fourier transform IR (FTIR), X-ray diffraction (XRD), Field Emission-Scanning Electron Microscope (FESEM). The performance of the reverse osmosis process of the neat and the modified PA(TFC) membranes in terms of water flux and salt rejection (%) was investigated. The chlorine and biofouling resistance properties of the neat and the modified PA(TFC) membrane were evaluated. It is found that, the performance of the modified ZnO NPs/P(NIPAM)-g-PA(TFC) membrane is much better than the neat PA(TFC) membrane.

Antimicrobial silver-loaded polypropylene sutures modified by radiation-grafting

The aim of this work was to implement a radiation-grafting method for the surface functionalization of polypropylene (PP) suture threads with N-vinyl imidazole (NVI) for the subsequent loading of silver (Ag) particles onto the surface. Grafting of NVI required the previous grafting of hydroxyethyl methacrylate (HEMA) or N-isopropyl acrylamide (NIPAAm) to finally obtain the composite materials [(PP-g-HEMA)-g-NVI]/Ag and [(PP-g-NIPAAm)-g-NVI]/Ag. Functionalized PP monofilaments were characterized by FTIR-ATR, SEM, EDS, and TGA. Antimicrobial efficiency and cytocompatibility demonstrated a strong dependence on the amount of Ag immobilized on sutures surface. [(PP-g-HEMA)-g-NVI]/Ag and [(PP-g-NIPAAm)-g-NVI]/Ag filaments with contents in Ag ranging from 3 to 5 wt (%) combined antimicrobial activity against Escherichia coli and Staphylococcus aureus, and an adequate cytocompatibility. Overall, the implemented method may open an alternative way to design surgical suture threads that guarantee protection against opportunistic pathogens during wound healing.

Radiation grafting of acrylamide and maleic acid on chitosan and effective application for removal of Co(II) from aqueous solutions

The graft copolymerization has been proven as a superior polymerization technique because it combines the functional advantages of the grafted and base polymers. In this work, the radiation-induced grafting of acrylamide (AAm) and maleic acid (MA) onto chitosan (CTS) was developed and optimized by determining the grafting percentage and efficiency as a function of grafting conditions such as AAm, MA, and CTS concentrations, and absorbed dose. Fourier transform infrared spectroscopic analysis (FTIR) confirmed the graft copolymerization. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) further characterized the grafted copolymers and showed their high thermal stability. Using batch sorption experiments and 60Co as a radiotracer, poly(CTS-AAm) and poly(CTS-MA) were evaluated for Co(II) removal from aqueous solutions. The Co(II) removal increases with increasing time, pH, polymer, and Co(II) concentrations. Experimentally, P(CTS-AAm) and P(CTS-MA) show high sorption capacities of Co(II), i.e. 150mgg–1 and 421mgg–1, respectively, which makes them potential sorbents of Co(II) for water and wastewater treatment. Finally, the Co(II) sorption was examined using sorption isotherm and kinetic models. The sorption was best fitted to Langmuir model which suggests the sorption is of chemisorption type. On the other hand, the sorption kinetics was best represented by Elovich model which also indicates the chemical nature of Co(II) sorption on P(CTS-AAm) and P(CTS-MA).

Acrylamide grafting with Maltodextrin for adsorption of hazardous water pollutants Cu(II), Co(II) and Cr(III)

Acrylamide grafting with Maltodextrin for adsorption of hazardous water pollutants Cu(II), Co(II) and Cr(III)