Articles de revues : « POLYACRYLAMIDE-GUAR GUM »

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Dutta, Koushik, Beauty Das, Dipankar Mondal, Arpita Adhikari, Dipak Rana, Atis Kumar Chattopadhyay, Rajdeb Banerjee, Roshnara Mishra et Dipankar Chattopadhyay. « An ex situ approach to fabricating nanosilica reinforced polyacrylamide grafted guar gum nanocomposites as an efficient biomaterial for transdermal drug delivery application ». New Journal of Chemistry 41, n^o 17 (2017) : 9461–71. http://dx.doi.org/10.1039/c7nj01713h.

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Nayak, B?R, et R?P Singh. « Comparative studies on the flocculation characteristics of polyacrylamide grafted guar gum and hydroxypropyl guar gum ». Polymer International 50, n^o 8 (2001) : 875–84. http://dx.doi.org/10.1002/pi.708.

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Abdel-Halim, E. S., M. H. El-Rafie et Salem S. Al-Deyab. « Polyacrylamide/guar gum graft copolymer for preparation of silver nanoparticles ». Carbohydrate Polymers 85, n^o 3 (juin 2011) : 692–97. http://dx.doi.org/10.1016/j.carbpol.2011.03.039.

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Musa, Tagwa A., Ahmed F. Ibrahim, Hisham A. Nasr-El-Din et Anas M. Hassan. « New insights into guar gum as environmentally friendly polymer for enhanced oil recovery in high-salinity and high-temperature sandstone reservoirs ». Journal of Petroleum Exploration and Production Technology 11, n^o 4 (1 février 2021) : 1905–13. http://dx.doi.org/10.1007/s13202-020-01080-3.

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AbstractChemical enhanced oil recovery (EOR) processes are usually used as additives for hydrocarbon production due to its simplicity and relatively reasonable additional production costs. Polymer flooding uses polymer solutions to increase oil recovery by decreasing the water/oil mobility ratio by increasing the viscosity of the displacing water. The commonly used synthetic water-soluble polymer in EOR application is partially hydrolyzed polyacrylamide (HPAM). However, synthetic polymers in general are not attractive because of high cost, environmental concerns, limitation in high temperature, and high-salinity environment. Guar gum is an environmentally friendly natural water-soluble polymer available in large quantities in many countries and widely used in various applications in the oil and gas industry especially in drilling fluids and hydraulic fracturing operations; however, very limited studies investigated on guar as a polymer for EOR and no any study investigated on its uses in high-temperature and high -salinity reservoirs. The objective of this study is to confirm the use of guar gum as a natural polymer for EOR applications in sandstone reservoirs and investigate its applicability for high-temperature and high-salinity reservoirs. The study experimentally investigated rheological characteristics of a natural polymer obtained from guar gum with consideration of high temperature (up to 210 °F) and high salinity (up to 20% NaCl) and tested the guar solution as EOR polymer. The results of this study show that the guar solution can be used as an environmentally friendly polymer to enhance oil recovery. Based on the results, it can be concluded that guar gum shows shear-thinning behavior and strongly susceptible to microbial degradation but also shows a very good properties stability in high temperature and salinity, where in low shear rate case, about 100 cp viscosity can be achieved at 210 °F for polymer prepared in deionized water. Guar polymer shows good viscosity in the presence of 20% NaCl where the viscosity is acceptable for temperature less than 190 °F. Also, the flooding experiment shows that the recovery factor can be increased by 16%.

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Ni, Weijun, Yubo Lian, Yan Wei, Bo Zheng, Man Liu, Le Qu et Ling Zhou. « Fenton-like oxidation of Hydroxypropyl guar gum catalysed by Cu(II) complex at high pH ». E3S Web of Conferences 329 (2021) : 01005. http://dx.doi.org/10.1051/e3sconf/202132901005.

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Large amounts of wastewater containing hydroxypropyl guar gum (HPGG), polyacrylamide (PAM) and carboxymethyl cellulose (CMC) are produced in the process of fracturing. In the work, a Fentonlike system in the presence of H2O2 was employed to degrade wastewater. The effects of oxidant concentration, catalyst dosage, the temperature and pH on the degradation efficiency of the polymer were studied in detail. Results showed that the prepared complex (Cu(II)L) exhibited a great catalytic effects in the range of pH 7-12. It was also found that under the conditions of 45℃ and pH=10, when the amount of H2O2 was 5.0% (mass ratio to hydroxypropyl guar gum) and the amount of Cu (II)L complex was 10%, HPGG had a great reduction rate, and its viscosity value can be reduced from 18 to 6.47.

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Berdugo-Clavijo, Carolina, Gabrielle Scheffer, Arindom Sen et Lisa M. Gieg. « Biodegradation of Polymers Used in Oil and Gas Operations : Towards Enzyme Biotechnology Development and Field Application ». Polymers 14, n^o 9 (3 mai 2022) : 1871. http://dx.doi.org/10.3390/polym14091871.

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Linear and crosslinked polymers are commonly used in the oil and gas industry. Guar-derived polymers have been extensively utilized in hydraulic fracturing processes, and recently polyacrylamide and cellulose-based polymers have also found utility. As these polymers are used during various phases of the hydraulic fracturing process, they can accumulate at formation fracture faces, resulting in undesired filter cakes that impede oil and gas recovery. Although acids and chemical oxidizers are often added in the fracturing fluids to degrade or ‘break’ polymer filter cakes, the constant use of these chemicals can be hazardous and can result in formation damage and corrosion of infrastructure. Alternately, the use of enzymes is an attractive and environmentally friendly technology that can be used to treat polymer accumulations. While guar-linkage-specific enzyme breakers isolated from bacteria have been shown to successfully cleave guar-based polymers and decrease their molecular weight and viscosity at reservoir conditions, new enzymes that target a broader range of polymers currently used in hydraulic fracturing operations still require research and development for effective application. This review article describes the current state-of-knowledge on the mechanisms and enzymes involved in biodegradation of guar gum, polyacrylamide (and hydrolyzed polyacrylamide), and carboxymethyl cellulose polymers. In addition, advantages and challenges in the development and application of enzyme breaker technologies are discussed.

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Quezada, Gonzalo R., Williams Leiva, Jorge H. Saavedra, Pedro Robles, Edelmira Gálvez et Ricardo I. Jeldres. « A Molecular Dynamics Simulation of Polymers’ Interactions with Kaolinite (010) Surfaces in Saline Solutions ». Polymers 14, n^o 18 (15 septembre 2022) : 3851. http://dx.doi.org/10.3390/polym14183851.

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The search for polymers that meet the demands of the water recovery process in mining is a contingent challenge. Both the presence of clays and saline waters can impair water recovery from tailings when conventional flocculants are used. In this work, the adsorption of polyacrylamide (PAM), hydrolyzed polyacrylamide (HPAM), poly(2-acrylamido-2-methyl-1-propane sulfonic acid) (PAMPS), polyacrylic acid (PAA), polyethylene oxide (PEO), and guar gum (GUAR) on a kaolinite surface (010) was investigated using classical molecular dynamics. The results show that the presence of sodium chloride modifies the affinities of the polymers with kaolinite (010). At low salt concentrations, the PAM and GUAR polymers generally show higher adsorption due to the formation of hydrogen bridges. However, the highest adsorptions occur in salt solutions in the presence of HPAM by cationic bridging with sodium ions as a mediator. This high affinity of HPAM is not efficient for flocculation because it re-disperses the particles, but it is promising for the design of new additives produced by grafting HPAM groups onto advanced polymers.

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Gupta, Pawan, Vishnu Chandrasekharan Nair et Jitendra S. Sangwai. « Phase Equilibrium of Methane Hydrate in Aqueous Solutions of Polyacrylamide, Xanthan Gum, and Guar Gum ». Journal of Chemical & ; Engineering Data 64, n^o 4 (avril 2019) : 1650–61. http://dx.doi.org/10.1021/acs.jced.8b01194.

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Mahmoud, R. « Investigation of Partially Methylolated Polyacrylamide Guar Gum by FTIR and Thermal Properties ». British Journal of Applied Science & ; Technology 17, n^o 6 (10 janvier 2016) : 1–11. http://dx.doi.org/10.9734/bjast/2016/28761.

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Zhu, Jingjing, Shuang Guan, Qianqian Hu, Guanghui Gao, Kun Xu et Pixin Wang. « Tough and pH-sensitive hydroxypropyl guar gum/polyacrylamide hybrid double-network hydrogel ». Chemical Engineering Journal 306 (décembre 2016) : 953–60. http://dx.doi.org/10.1016/j.cej.2016.08.026.

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Huang, Haolin, Junzhang Lin, Weidong Wang et Shuang Li. « Biopolymers Produced by Sphingomonas Strains and Their Potential Applications in Petroleum Production ». Polymers 14, n^o 9 (9 mai 2022) : 1920. http://dx.doi.org/10.3390/polym14091920.

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The genus Sphingomonas was established by Yabuuchi et al. in 1990, and has attracted much attention in recent years due to its unique ability to degrade environmental pollutants. Some Sphingomonas species can secrete high-molecular-weight extracellular polymers called sphingans, most of which are acidic heteropolysaccharides. Typical sphingans include welan gum, gellan gum, and diutan gum. Most sphingans have a typical, conserved main chain structure, and differences of side chain groups lead to different rheological characteristics, such as shear thinning, temperature or salt resistance, and viscoelasticity. In petroleum production applications, sphingans, and their structurally modified derivatives can replace partially hydrolyzed polyacrylamide (HPAM) for enhanced oil recovery (EOR) in high-temperature and high-salt reservoirs, while also being able to replace guar gum as a fracturing fluid thickener. This paper focuses on the applications of sphingans and their derivatives in EOR.

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Amin, Rabab, et Amal El-Ebissy. « Characterization of partially methylolated polyacrylamide guar gum by FTIR and fastness properties on to printing cotton fabric ». Research Journal of Textile and Apparel 20, n^o 1 (14 mars 2016) : 2–13. http://dx.doi.org/10.1108/rjta-09-2015-0026.

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Purpose The purpose of this study was to prepare partially methylolated polyacrylamide-guar gum via graft copolymerization of acryalmide and guar gum using the potassium bromate/thiourea redox system. Design/methodology/approach Using HCHO (40 per cent), amide groups in the composite are converted to reactive composite. The reactive composites (N-methylolated [PAam-GG]) were used as pastes for printing cotton fabrics with pigment dye, under a variety of conditions. Variables studied include the amount of binder incorporated into the printing paste and different catalysts incorporated into the printing paste. Originality/value Characterization of printing samples under different conditions, including amount of the beneficial effects of varying conditions of printing on the color strength (K/S); the color parameters L, a, b, h and c; and the change in color difference (ΔE) were also investigated. The Fourier transforms infrared spectra of printed cotton fabrics has followed each condition of printing. The obtained results indicate that the improvement in the printing process may be due to change in molecular configuration as a result of the variation in chemical bond.

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Jang, Jungyeon. « A Review of the Application of Biopolymers on Geotechnical Engineering and the Strengthening Mechanisms between Typical Biopolymers and Soils ». Advances in Materials Science and Engineering 2020 (9 janvier 2020) : 1–16. http://dx.doi.org/10.1155/2020/1465709.

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The use of admixtures in soils to improve their properties has been implemented since ancient times. Diverse conventional admixtures such as lime, fly ash, and cement have been added to soils. Also, petrochemicals and bacteria are increasingly used for soil improvement and soil stabilization both mechanically and chemically. However, the conventional admixtures for soils cause significant environmental problems (e.g., CO2 emission). Biopolymers can increasingly replace the conventional admixtures for the application of soil improvement and soil stabilization. Numerous studies have been conducted in the past decades to investigate the suitability and efficiency of various biopolymers for soil improvement. This paper focuses on the properties of the most common biopolymers (xanthan gum, gellan gum, agar, polyacrylamide, and guar gum) and gives the mechanism of biopolymer-treated soils for soil improvements proposed by researchers.

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Bajpai, U. D. N., Alka Jain et Sandeep Rai. « Grafting of polyacrylamide on to guar gum using K2S2O8 ascorbic acid redox system ». Journal of Applied Polymer Science 39, n^o 1112 (5 juin 1990) : 2187–204. http://dx.doi.org/10.1002/app.1990.070391101.

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Liu, Jimin, Xiangzhi Wang, Hua Cheng et Haixu Fan. « Orthogonal Design and Microstructure Mechanism Analysis of Novel Bentonite Polymer Slurry in Pipe Jacking ». Polymers 15, n^o 6 (15 mars 2023) : 1461. http://dx.doi.org/10.3390/polym15061461.

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The selection of an appropriate slurry ingredient and its percentage ratio is a vital and necessary task for engineers in slurry pipe jacking operations. However, traditional bentonite grouting materials are difficult to degrade because of their single and non-biodegradable composition. Nowadays crosslinked polymers have been widely considered due to their excellent performance and application in engineering practices, which enlighten novel polymer slurry in pipe jacking. This study innovatively proposed using boric acid crosslinked polymers added into polyacrylamide bentonite slurry, which not only solves the shortcomings of traditional grouting materials but also meets the general working performance requirements. The new slurry’s funnel viscosity, filter loss, water dissociation ratio and dynamic shear were tested according to an orthogonal experiment. Single factor range analysis was conducted to identify the optimal mix proportion based on an orthogonal design, and the formation behavior of mineral crystals and microstructure characteristics were evaluated by X-ray diffraction and scanning electron microscopy respectively. According to the results, guar gum and borax form a dense boric acid crosslinked polymer through cross-linking reaction. The internal structure grew tighter and more continuous as the crosslinked polymer concentration grew. It improved the anti-permeability plugging action and viscosity of slurries by 36.1~94.3%. The optimal proportions of sodium bentonite, guar gum, polyacrylamide, borax, and water were 10%, 0.2%, 0.25%, 0.1%, and 89.45% respectively. All these works indicated that the improvement of slurry composition by using boric acid crosslinked polymers was feasible.

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Zhang, Zhenchao. « Combined treatment of hydroxypropyl guar gum in oilfield fracturing wastewater by coagulation and the UV/H2O2/ferrioxalate complexes process ». Water Science and Technology 77, n^o 3 (1 novembre 2017) : 565–75. http://dx.doi.org/10.2166/wst.2017.552.

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Abstract Hydroxypropyl guar gum is considered to be a main component of oilfield fracturing wastewater (OFW). This work is intended to optimize the experimental conditions for the maximum oxidative degradation of hydroxypropyl guar gum by the coagulation and UV/H2O2/ferrioxalate complexes process. Optimal reaction conditions were proposed based on the chemical oxygen demand (COD) removal efficiency and UV_vis spectra analysis. The overall removal efficiency of COD reached 83.8% for a dilution ratio of raw wastewater of 1:2, pH of 4 and FeCl3 loading of 1,000 mg/L in the coagulation process; the dosage of H2O2 (30%,v/v) was 0.6% (v/v) and added in three steps, the n(H2O2)/n(Fe2+) was 2:1, n(Fe2+)/n(C2O42−) was 3:1 and pH was 4 in the UV/H2O2/ferrioxalate complexes process; pH was adjusted to 8.5–9 by NaOH and then cationic polyacrylamide (CPAM) of 2 mg/L was added in the neutralization and flocculation process. The decrease in COD during the coagulation process reduced the required H2O2 dosage and improved efficiency in the subsequent UV/H2O2/ferrioxalate complexes process. Furthermore, COD removal efficiency significantly increased by more than 13.4% with the introduction of oxalate compared with UV/Fenton. The UV_vis spectra analysis results indicated that the coagulation and UV/H2O2/ferrioxalate complexes process could efficiently remove the hydroxypropyl guar gum dissolved in OFW. An optimal combination of these parameters produced treated wastewater that met the GB8978-1996 Integrated Wastewater Discharge Standard level III emission standard.

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Tsujino, T., A. Shima et H. Nanjo. « Effects of Various Polymer Additives on Cavitation Damage ». Proceedings of the Institution of Mechanical Engineers, Part C : Journal of Mechanical Engineering Science 200, n^o 4 (juillet 1986) : 231–35. http://dx.doi.org/10.1243/pime_proc_1986_200_123_02.

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Cavitation damage tests in various polymer solutions have been carried out using a vibratory damage apparatus. The relation of weight loss-time, the damage patterns, the cavitation clouds and the damaged area in a polyacrylamide solution, a sodium carboxy-methylcellulose solution, a hydroxyethylcellulose solution, a guar gum solution and a polyethylene oxide solution are compared and are discussed. It is found that the weight losses in the PAM solution and the Polyox solution, which are more elastic, are smaller than the cases of the other polymer solutions and water after sixty minutes exposure to cavitation.

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Zhou, Yunxu, et Subhash N. Shah. « Rheological Properties and Frictional Pressure Loss of Drilling, Completion, and Stimulation Fluids in Coiled Tubing ». Journal of Fluids Engineering 126, n^o 2 (1 mars 2004) : 153–61. http://dx.doi.org/10.1115/1.1669033.

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The rheological properties and friction pressure losses of several common well-drilling, completion, and stimulation fluids have been investigated experimentally. These fluids include polymeric fluids—Xanthan gum, partially hydrolyzed polyacrylamide (PHPA), guar gum, and hydroxyethyl cellulose (HEC), bentonite drilling mud, oil-based drilling mud, and guar-based fracturing slurries. Rheological measurements using a Bohlin CS 50 rheometer and a model 35 Fann viscometer showed that these fluids exhibit shear thinning and thermal thinning behavior except the bentonite drilling mud whose viscosity increased as the temperature was raised. Flow experiments using a full-scale coiled tubing test facility showed that the friction pressure loss in coiled tubing is significantly higher than in straight tubing. Since the polymeric fluids displayed drag reducing property, their drag reduction behavior in straight and coiled tubings was analyzed and compared. Plots of drag reduction vs. generalized Reynolds number indicate that the drag reduction in coiled tubing was not affected by polymer concentration as much as in straight tubing. The onsets of turbulence and drag reduction in coiled tubing were significantly delayed as compared with straight tubing. The effect of solids content on the friction pressure losses in coiled tubing is also briefly discussed.

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Wan, Xiaofang, Youming Li, Xiaojun Wang, Sili Chen et Xiaoyang Gu. « Synthesis of cationic guar gum-graft-polyacrylamide at low temperature and its flocculating properties ». European Polymer Journal 43, n^o 8 (août 2007) : 3655–61. http://dx.doi.org/10.1016/j.eurpolymj.2007.05.037.

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Abdel-Halim, E. S., et Salem S. Al-Deyab. « Hydrogel from crosslinked polyacrylamide/guar gum graft copolymer for sorption of hexavalent chromium ion ». Carbohydrate Polymers 86, n^o 3 (août 2011) : 1306–12. http://dx.doi.org/10.1016/j.carbpol.2011.06.033.

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Bajpai, U. D. N., et Alka Jain. « Grafting of polyacrylamide on to guar gum with the redox system potassium bromate/thiomalic acid ». Polymer International 31, n^o 1 (1993) : 1–7. http://dx.doi.org/10.1002/pi.4990310102.

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Efimov, Konstantin V., Evgeny N. Egorov, Nikolay F. Ushmarin et Nikolay I. Koltsov. « Effect of hydrosorption polymers on the properties of water-swellable rubber ». Butlerov Communications 64, n^o 10 (31 octobre 2020) : 90–93. http://dx.doi.org/10.37952/roi-jbc-01/20-64-10-90.

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Currently, in the oil and gas industry there is a growing demand for sealing elements capable of limited swelling upon contact with water and sealing the annular space of certain sections of the well. The swelling capacity of the sealing elements is predetermined by a well-chosen combination of polymer base and targeted functional ingredients. At the moment, a big drawback of water-swellable sealing elements is the loss of their sealing ability due to the washing out of hydrosorption additives from the sealing element. In this regard, in this work, the effect of hydrosorption polymers (polyacrylamide, sodium carboxymethylcellulose, polyvinyl alcohol and guar gum) on the properties of water-swellable rubber based on a combination of nitrile-butadiene SKN 1855, acrylate nipol AR22 and chloroprene CR 232 rubbers and epoxy 20 with sulfur curing system. The rubber mixture was prepared by mixing rubbers with ingredients on a laboratory roll LB 320 160/160. The rheological characteristics of the rubber compound were studied on an MDR 3000 Basic rheometer at 150 °C. Standard rubber samples were vulcanized at 150 °C for 30 min in a P-V-100-3RT-2-PCD vulcanization press. The main properties of vulcanizates were determined according to the standards in force in the rubber industry. It is shown that the introduction of polyacrylamide together with sodium carboxymethyl cellulose, polyvinyl alcohol and guar gum into a rubber compound leads to a change in its rheological parameters. Vulcanizates containing a combination of polymers are characterized by lower values of the conventional tensile strength and rebound elasticity, but higher elongation at break and the degree of swelling in distilled and formation water as compared to the vulcanizate of the base version of the rubber mixture.

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Quezada, Gonzalo R., Norman Toro, Jorge Saavedra, Pedro Robles, Iván Salazar, Alessandro Navarra et Ricardo I. Jeldres. « Molecular Dynamics Study of the Conformation, Ion Adsorption, Diffusion, and Water Structure of Soluble Polymers in Saline Solutions ». Polymers 13, n^o 20 (14 octobre 2021) : 3550. http://dx.doi.org/10.3390/polym13203550.

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Polymers have interesting physicochemical characteristics such as charge density, functionalities, and molecular weight. Such attributes are of great importance for use in industrial purposes. Understanding how these characteristics are affected is still complex, but with the help of molecular dynamics (MD) and quantum calculations (QM), it is possible to understand the behavior of polymers at the molecular level with great consistency. This study was applied to polymers derived from polyacrylamide (PAM) due to its great use in various industries. The polymers studied include hydrolyzed polyacrylamide (HPAM), poly (2-acrylamido-2-methylpropanesulfonate) (PAMPS), polyacrylic acid (PAA), polyethylene oxide polymer (PEO), and guar gum polysaccharide (GUAR). Each one has different attributes, which help in understanding the effects on the polymer and the medium in which it is applied along a broad spectrum. The results include the conformation, diffusion, ion condensation, the structure of the water around the polymer, and interatomic polymer interactions. Such characteristics are important to selecting a polymer depending on the environment in which it is found and its purpose. The effect caused by salinity is particular to each polymer, where polymers with an explicit charge or polyelectrolytes are more susceptible to changes due to salinity, increasing their coiling and reducing their mobility in solution. This naturally reduces its ability to form polymeric bridges due to having a polymer with a smaller gyration radius. In contrast, neutral polymers are less affected in their structure, making them favorable in media with high ionic charges.

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Ibrahim, N. A., M. M. Rashad et M. H. Abo‐Shosha. « Polyacrylamide/Guar Gum Adduct as a New Thickener for Reactive Printing of Wool and Nylon‐6 ». Polymer-Plastics Technology and Engineering 42, n^o 5 (11 janvier 2003) : 757–77. http://dx.doi.org/10.1081/ppt-120024994.

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Paradelo, R., R. Basanta et M. T. Barral. « Water-holding capacity and plant growth in compost-based substrates modified with polyacrylamide, guar gum or bentonite ». Scientia Horticulturae 243 (janvier 2019) : 344–49. http://dx.doi.org/10.1016/j.scienta.2018.08.046.

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Birajdar, Ravindra P., Sudha S. Patil, Vijaykumar V. Alange et Raghavendra V. Kulkarni. « Electrically Triggered Transdermal Drug Delivery Utilizing Poly(Acrylamide)-graft-Guar Gum : Synthesis, Characterization and Formulation Development ». Current Applied Polymer Science 3, n^o 1 (9 janvier 2019) : 64–74. http://dx.doi.org/10.2174/2452271602666181031093243.

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Objective: The study aimed to prepare electrically-triggered transdermal drug delivery systems (ETDS) using electrically responsive polyacrylamide-graft-gaur gum (PAAm-g-GaG) copolymer. Methods: The PAAm-g-GaG copolymer was synthesized by adopting free radical polymerization grafting method. This PAAm-g-GaG copolymer hydrogel acts as a drug reservoir and blend films of Guar Gum (GaG) and Polyvinyl Alcohol (PVA) were included as Rate Controlling Membranes (RCM) in the system. The PAAm-g-GaG copolymer was characterized by FTIR, neutralization equivalent values, thermogravimetric analysis and elemental analysis. Results: On the basis of results obtained, it is implicit that the drug permeation decreased with an increase in the concentration of glutaraldehyde and RCM thickness; while drug permeation rate was increased with increasing applied electric current strength from 2 to 8 mA. A two fold increase in flux values was observed with the application of DC electric current. An increase in drug permeation was witnessed under on condition of electric stimulus and permeation was decreased when electric stimulus was "off". The skin histopathology study confirmed the changes in skin structure when electrical stimulus was applied. Conclusion: The electrically-sensitive PAAm-g-GaG copolymer is a useful biomaterial for transdermal drug delivery application.

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M. P., Gowrav, Umme Hani, Hosakote G. Shivakumar, Riyaz Ali M. Osmani et Atul Srivastava. « Polyacrylamide grafted guar gum based glimepiride loaded pH sensitive pellets for colon specific drug delivery : fabrication and characterization ». RSC Advances 5, n^o 97 (2015) : 80005–13. http://dx.doi.org/10.1039/c5ra17257h.

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Pal, Sagar, S. Ghorai, M. K. Dash, S. Ghosh et G. Udayabhanu. « Flocculation properties of polyacrylamide grafted carboxymethyl guar gum (CMG-g-PAM) synthesised by conventional and microwave assisted method ». Journal of Hazardous Materials 192, n^o 3 (septembre 2011) : 1580–88. http://dx.doi.org/10.1016/j.jhazmat.2011.06.083.

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Yang, Kaiji, Jinghuan Chen, Qingjin Fu, Xuji Dun et Chunli Yao. « Preparation of novel amphoteric polyacrylamide and its synergistic retention with cationic polymers ». e-Polymers 20, n^o 1 (28 avril 2020) : 162–70. http://dx.doi.org/10.1515/epoly-2020-0026.

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AbstractA novel amphoteric polyacrylamide (PDAA) was prepared by inverse emulsion polymerization. The influence of its cationic degree and molecular weight on retention property was discussed. Then, the chemical structure and micromorphology of the obtained PDAA were characterized by Fourier infrared spectrum (FTIR), NMR hydrogen spectrum (1H NMR), gel permeation chromatography (GPC), and scanning electron microscope (SEM). Finally, the synergistic retention effects of polydimethyldiallylammonium chloride (PDADMAC), cationic starch (CS), cationic guar gum (CHPG), cationic chitosan (CTS), and polyamine (PA) on the novel PDAA were investigated. The results showed that the optimum cationic degree and molecular weight of PDAA were 25% and 4 million, respectively. The chemical structure of PDAA was confirmed by FTIR, 1H NMR, and GPC. SEM showed that the particle size of PDAA was between 150 and 600 nm, and the particles were very stable because no broken particles were found. In addition, most of the five cationic polymers have good synergistic retention effect on PDAA, and the order of synergistic effect was PDAA/PDADMAC > PDAA/CTS > PDAA/CS > PDAA/CHPG > PDAA/PA.

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Xu, Xiuru, Chubin He, Feng Luo, Hao Wang et Zhengchun Peng. « Robust Conductive Hydrogels with Ultrafast Self-Recovery and Nearly Zero Response Hysteresis for Epidermal Sensors ». Nanomaterials 11, n^o 7 (19 juillet 2021) : 1854. http://dx.doi.org/10.3390/nano11071854.

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Robust conductive hydrogels are in great demand for the practical applications of smart soft robots, epidermal electronics, and human–machine interactions. We successfully prepared nanoparticles enhanced polyacrylamide/hydroxypropyl guar gum/acryloyl-grafted chitosan quaternary ammonium salt/calcium ions/SiO2 nanoparticles (PHC/Ca2+/SiO2 NPs) conductive hydrogels. Owing to the stable chemical and physical hybrid crosslinking networks and reversible non-covalent interactions, the PHC/Ca2+/SiO2 NPs conductive hydrogel showed good conductivity (~3.39 S/m), excellent toughness (6.71 MJ/m3), high stretchability (2256%), fast self-recovery (80% within 10 s, and 100% within 30 s), and good fatigue resistance. The maximum gauge factor as high as 66.99 was obtained, with a wide detectable strain range (from 0.25% to 500% strain), the fast response (25.00 ms) and recovery time (86.12 ms), excellent negligible response hysteresis, and good response stability. The applications of monitoring the human’s body movements were demonstrated, such as wrist bending and pulse tracking.

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Soppimath, Kumaresh S., Anandrao R. Kulkarni et Tejraj M. Aminabhavi. « Chemically modified polyacrylamide-g-guar gum-based crosslinked anionic microgels as pH-sensitive drug delivery systems : preparation and characterization ». Journal of Controlled Release 75, n^o 3 (août 2001) : 331–45. http://dx.doi.org/10.1016/s0168-3659(01)00404-7.

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Soppirnath, Kumaresh S., et Tejraj M. Aminabhavi. « Water transport and drug release study from cross-linked polyacrylamide grafted guar gum hydrogel microspheres for the controlled release application ». European Journal of Pharmaceutics and Biopharmaceutics 53, n^o 1 (janvier 2002) : 87–98. http://dx.doi.org/10.1016/s0939-6411(01)00205-3.

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Xu, Ke, Yongjun Lu, Jin Chang et Yang Li. « Research Progress of High Temperature Resistant Fracturing Fluid System ». Journal of Physics : Conference Series 2076, n^o 1 (1 novembre 2021) : 012039. http://dx.doi.org/10.1088/1742-6596/2076/1/012039.

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Abstract China has made significant progress in the efficient exploration and development of deep-seated oil and gas wells. Reservoir reformation, as the core tool of high-temperature deep-seated exploration and development, puts forward a strong demand for fracturing fluids. The ultra-high temperature fracturing fluid system developed in my country is mainly divided into two types: ultra-high temperature guar gum fracturing fluid and ultra-high temperature synthetic polyacrylamide fracturing fluid. The high temperature resistant fracturing fluid system is mainly composed of high temperature resistant thickener, high temperature resistant crosslinking agent and temperature stabilizing additives and other additives. Based on indoor research and a large amount of literature, this article summarizes the research and application of high temperature resistant fracturing fluid system, high temperature resistant thickener, high temperature resistant crosslinking agent and temperature stabilizing additives in my country in recent years, and pointed out the shortcomings and limitations of the high-temperature fracturing fluid, the technical direction of the development of high-temperature resistant fracturing fluid technology is proposed.

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Roy, Pialee, Paramita Karfa, Utpal Adhikari et Dipankar Sukul. « Corrosion inhibition of mild steel in acidic medium by polyacrylamide grafted Guar gum with various grafting percentage : Effect of intramolecular synergism ». Corrosion Science 88 (novembre 2014) : 246–53. http://dx.doi.org/10.1016/j.corsci.2014.07.039.

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Toti, Udaya S., Mahadevappa Y. Kariduraganavar, Kumaresh S. Soppimath et Tejraj M. Aminabhavi. « Sorption, diffusion, and pervaporation separation of water-acetic acid mixtures through the blend membranes of sodium alginate and guar gum-grafted-polyacrylamide ». Journal of Applied Polymer Science 83, n^o 2 (7 novembre 2001) : 259–72. http://dx.doi.org/10.1002/app.2241.

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Gupta, Pawan, et Jitendra S. Sangwai. « Formation and Dissociation Kinetics of Methane Hydrate in Aqueous Oilfield Polymer Solutions (Polyacrylamide, Xanthan Gum, and Guar Gum) and Their Performance Evaluation as Low-Dosage Kinetic Hydrate Inhibitors (LDHI) ». Energy & ; Fuels 33, n^o 7 (juillet 2019) : 6335–49. http://dx.doi.org/10.1021/acs.energyfuels.9b01204.

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Chandan, K. K., et G. P. Karmakar. « Drilling fluid waste treatment using polysaccharide-grafted copolymers ». APPEA Journal 59, n^o 1 (2019) : 34. http://dx.doi.org/10.1071/aj18229.

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A large amount of drilling fluid waste is produced as effluents during exploration and production of oil and gas. Such effluents need to be treated before their final disposal. Efficient coagulation/flocculation can reduce the total amount of disposed effluent, and both coagulation by inorganic salts and flocculation by synthetic flocculants are found to be very effective. The graft-copolymers-based flocculants were prepared using a potassium persulfate initiator solution made by grafting copolymerisation of polyacrylamide onto polysaccharide backbones (starch, guar gum and amylose) in our laboratory. The synthesised graft copolymers have been characterised using various instrumental methods of analysis. The effects of various synthetic flocculants and their concentrations have been studied in combination with the coagulants on coagulation/flocculation of bentonite-based drilling fluid waste have been studied. The effects of coagulant/flocculant dosage, electrolyte concentration and pH on the degree of flocculation of bentonite-based drilling fluid waste was investigated. It was observed that the increase in coagulant/flocculant dosage reduces the residual turbidity and improves the settling rate of the drilling fluid waste. At higher pH conditions, drilling fluid waste dispersions are highly flocculated and have high settling rates and low supernatant turbidity. The combined effect of salt concentration and coagulant/flocculant dosage improves the overall flocculation efficiency of the system.

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Kumbar, Sangamesh G., Ashok M. Dave et Tejraj M. Aminabhavi. « Release kinetics and diffusion coefficients of solid and liquid pesticides through interpenetrating polymer network beads of polyacrylamide-g-guar gum with sodium alginate ». Journal of Applied Polymer Science 90, n^o 2 (7 août 2003) : 451–57. http://dx.doi.org/10.1002/app.12675.

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Sen, Gautam, Sumit Mishra, Usha Jha et Sagar Pal. « Microwave initiated synthesis of polyacrylamide grafted guar gum (GG-g-PAM)—Characterizations and application as matrix for controlled release of 5-amino salicylic acid ». International Journal of Biological Macromolecules 47, n^o 2 (août 2010) : 164–70. http://dx.doi.org/10.1016/j.ijbiomac.2010.05.004.

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Srivastava, Arti, Vivek Mishra, Shailendra Kumar Singh et Rajesh Kumar. « One pot synthesis and characterization of industrially important graft copolymer (GOH-g-ACM) by using peroxymonosulphate/ mercaptosuccinic acid redox pair ». e-Polymers 9, n^o 1 (1 décembre 2009). http://dx.doi.org/10.1515/epoly.2009.9.1.58.

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AbstractGuar gum-g-polyacrylamide is a graft copolymer which is used for many industrial applications. This paper outlines the details of synthesis of guar gum -gacrylamide by using potassium peroxymonosulphate/ mercaptosuccinic acid redox pair in an inert atmosphere and their characterization by infrared spectroscopy, UV analysis and study of swelling and thermal properties. Grafting characteristics: %G, %E, %C, %A and %H were determined by using Fanta’s definition; rate of grafting was also calculated. On studying the effect of reaction conditions on grafting characteristics, it was found that the optimum concentration of peroxymonosulphate, mercaptosuccinic acid, hydrogen ion, acrylamide and guar gum for maximum % of grafting were 8.0×10-3, 3.2×10-3, 8.0×10-3, 16.0×10-2 mol dm-3 and 60.0×10-2 g dm-3 respectively. The optimum time duration and temperature of reaction were found to be 120 min and 40 °C respectively. During the study [H+] variation showed prompt changes on grafting characteristics. It was found that after 310 °C the polyacrylamide grafted guar gum was thermally more stable than pure guar gum.

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C, Chirayu, Nagaraja T.S et Vitthal K. Vijapure. « “FORMULATION AND EVALUATION OF TRANSDERMAL PATCHES OF PREDNISOLONE” ». Journal of Biomedical and Pharmaceutical Research 8, n^o 3 (14 juin 2019). http://dx.doi.org/10.32553/jbpr.v8i3.613.

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The purpose of this research work was to develop and evaluate transdermal patch of Prednisolone, using Xanthan gum, Guar gum and Polyacrylamide in different ratios prepared by the Glass Substrate Technique. The physicochemical compatibility of the polymers and the drug was evaluated by FTIR. The results suggested that no physicochemical incompatibility between the polymer and the drug. Drug free films were formulated and evaluated characteristics like flexibility and smoothness. Further drug loaded films were formulated and evaluated for thickness, weight uniformity, drug content, folding endurance and drug release. The XRD analysis confirmed the amorphous dispersion of the drug in the formulation. SEM analysis showed surface morphology of prepared formulations. Drug diffusion through cellophane membrane was carried out using Franz diffusion cell by in-vitro study. The film prepared with formulation PDS 9 showed maximum diffusion release at the end of 24 hours. It is shown that drug release follows order and non Fikinian mechanism of release diffusion. The PDS 9 formulation was found to be stable with respect to drug content as well as physical changes at 40 ºC and 75 % RH. Keywords: Transdermal drug delivery, Prednisolone, Xanthan gum, Guar gum, Polyacrylamide.

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Sayed, Asmaa, Mai M. Mohamed, Manar El-Sayed Abdel-raouf et Ghada A. Mahmoud. « Radiation Synthesis of Green Nanoarchitectonics of Guar Gum-Pectin/Polyacrylamide/Zinc Oxide Superabsorbent Hydrogel for Sustainable Agriculture ». Journal of Inorganic and Organometallic Polymers and Materials, 16 août 2022. http://dx.doi.org/10.1007/s10904-022-02465-z.

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AbstractIn the current study, the performance of superabsorbent hydrogel composites comprised of Guar gum-Pectin/Polyacrylamide/ZnO crosslinked with gamma irradiation (10 kGy) has been investigated for sustainable agriculture. The claimed composites (GG/PC/PAAm/ZnOx) were characterized by FTIR, TGA, and AFM. The swelling capacity data reveal that the equilibrium water swelling (EW) of the composites was increased by increasing the ZnO content from 600 to 1050 g/g for zero to the highest concentration of ZnO, respectively. Furthermore, the physical properties of the soil mixed with the hydrogels were improved; water holding capacity (WHC) increased to 66% and water retention (WR) kept at 15% after 20 days. The composites showed a good degradability in the biodegradation test. They also portrayed super-absorption capacity at three swelling/deswelling cycles. This advancement is important for reducing water consumption through the irrigation of arid lands. The prepared composites were proved as excellent candidates in sustainable agriculture applications.

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Hussain, Daud, Suhail Ayoub Khan, Tabrez Alam Khan et Salman S. Alharthi. « Efficient liquid phase confiscation of nile blue using a novel hybrid nanocomposite synthesized from guar gum-polyacrylamide and erbium oxide ». Scientific Reports 12, n^o 1 (29 août 2022). http://dx.doi.org/10.1038/s41598-022-18591-0.

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AbstractIn recent times, biopolymer-metal oxide nanocomposites have gained prominent importance in the attenuation of environmental toxicants from aqueous phase. But lanthanide oxide-based biopolymer nanocomposites have scantly been evaluated for their adsorption potential. A novel guar gum-polyacrylamide/erbium oxide nanocomposite (GG-PAAm/Er2O3 NC) adsorbent was synthesized by copolymerization of guar gum (GG) and acrylamide (AAm) utilizing N-N′-methylenebisacrylamide as a crosslinker and Er2O3 as a reinforcing agent. The adsorptive efficacy of GG-PAAm/Er2O3 nanocomposite was evaluated using nile blue (NB) as a model pollutant dye from aquatic system. The prepared adsorbent was characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) analysis, Brunauer–Emmett–Teller (BET) analysis, thermogravimetric analysis, scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM–EDX), and high-resolution transmission electron microscopy (HRTEM). The optimal process parameters, which include dosage (0.8 g/L), agitation time (40 min), initial solution pH (6), and initial NB concentration (80 mg/L) were determined by batch methodology. The equilibrium data for NB confiscation was better expressed by Langmuir isotherm model, with maximal adsorption effectiveness (Qm) of 225.88 mg NB/g demonstrating the actively monolayer adsorption onto homogeneous surface of GG-PAAm/Er2O3 NC. The kinetics of NB sorption process onto GG-PAAm/Er2O3 NC was reliable with pseudo-second order model. Thermodynamic parameters such as ΔH° (15–17 kJ/mol) and ΔS° (0.079–0.087 kJ/mol/K), and − ΔG° (8.81–10.55 kJ/mol) for NB validated the endothermic, an increased randomness at the GG-PAAm/Er2O3–NB interface, and spontaneity and feasibility of the process, respectively. The spent nanocomposite was effectively regenerated with NaOH, and could be reused proficiently for five runs demonstrating the high reusability potential of the nanocomposite. The commendable removal efficiency and high reusability of GG-PAAm/Er2O3 NC recommended it to be a highly competent adsorbent for cationic dyes particularly NB diminution from aqueous waste.

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Ferreira, Vitor Hugo, Karl Clinckspoor, Alane Vermelho, Veronica Cardoso et Rosangela Moreno. « Mechanical Degradation of Biopolymers for Enhanced Oil Recovery Applications ». SPE Journal, 1 février 2022, 1–21. http://dx.doi.org/10.2118/209579-pa.

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Summary Polymer degradation is detrimental to enhanced oil recovery (EOR) because it ultimately leads to solution viscosity loss. Molecular breakage during flow owing to high stresses, known as mechanical degradation, can occur in numerous stages during field polymer injection. One of the reasons biopolymers are promising for EOR is their enhanced mechanical stability compared to their polyacrylamide counterparts. This study presents a comparative investigation of the mechanical degradation of biopolymers with potential applications in EOR. The mechanical degradation was evaluated by flowing the solutions through a short-length capillary (internal diameter of 0.127 mm and length of 10 mm) and then testing their viscosity loss through a rheometer. Nine flow velocities were tested between 0.13 and 66 m/s (shear rates between 8.29 × 103 and 1.66 × 107 s−1) in addition to the undegraded baseline. Four biopolymers were evaluated [xanthan gum (XG), scleroglucan (SCLG), schizophyllan (SCP), and guar gum (GG)] and compared to two polyacrylamides [hydrolyzed polyacrylamide (HPAM) and HPAM-AMPS (2-acrylamido-2-methylpropane sulfonic acid)] that serve as benchmarks for EOR processes. All the polymers were evaluated in three different concentrations (100, 500, and 2,000 ppm) in synthetic seawater (3.01% total dissolved solids). The degradation was evaluated through the Ostwald-de Waele indices. The consistency index (K) indicates loss of overall viscosity, and the behavior index (n) accounts for the loss of pseudoplasticity. Overall, the mechanical degradation correlated positively with shear rate and negatively with polymer concentration. When increasing the polymer concentration, the dominant mechanisms at play were macromolecule extension inhibition, caused by interactions with surrounding molecules, and hydrodynamic volume reduction. The biopolymers displayed superior resistance to mechanical degradation than the synthetic ones, with XG being the most resistant polymer. In this work, the main factors for the mechanical degradation resistance of different polymers were rigidity of the polymer structure in solution and the molar mass of the polymer chains.

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Harshan, Krishnan, A. Prashanth Rajan, Danie Kingsley, Rahul Amin Sheikh, Jemima Aashmi et Anand Prem Rajan. « Plant-based biopolymers for wastewater pollutants mitigation ». Physical Sciences Reviews, 4 avril 2023. http://dx.doi.org/10.1515/psr-2022-0220.

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Abstract Pollution is one of the most pressing issues of modern times. Effluent in the world is escalating due to the exponential growth in the industrial and agricultural sectors. The effluents contain heavy metals, pesticides, and inorganic substances ultimately leading to the deterioration of the ecosystem. Even though there are numerous wastewater treatment methods like adsorption, membrane separation, ion exchange, and physical, mechanical, and chemical treatments. They are expensive and have the risk of second-hand pollution. Biopolymers are alternate and superior to synthetic polymers due to their environmentally friendly approach and high efficiency in treating wastewater. The most prominent plant-based biopolymers for the treatment of pollutants are cellulose, starch, carrageenan, alginate, xylan, inulin, pectin, and tragacanth. These have their advantages and disadvantages in bioremediation. The mechanism of pollution removal has adsorption, flocculation, bridge formation, and electrostatic patches. They are biodegradable as they are natural in origin. They have proved to remove toxic pollutants like chitosan, pullulan, polyhydroxy alkonates and butyrates, dextran, starch and cellulose, polyvinyl alcohol and polycaprolactone, gelatin, collagen and wheat gluten, alginate, heparin, and pectin to name a few. Biopolymers are also sourced from diverse sources like agricultural wastes and well-known sources like plants, animals, and microbes. Biopolymer and its composites are utilized as coagulants and flocculants. They are cellulose graft polyacrylamide, anionic sodium carboxymethylcellulose, guar gum graft polyacrylamide, pectin polyacrylamide, starch, and tannin. Nanotechnology has led to the development of elite nanohybrid bio-adsorbents to actively remove pollutants. These nano adsorbents have been targeting pollutants like azo dyes, bovine serum albumin, cationic dyes, parabens, and methylene blue among others. Biopolymer composites are also widely used for diverse applications primarily due to their enhanced mechanical and thermal properties. Biopolymers from natural and synthetic sources can be modified and used as per the requirement.

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