The synthesis of graft copolymer (gellan gum-g-N-vinyl-2-pyrrolidone) is carried out in nitrogen atmosphere using potassium bromate and silver as redox system. The reaction conditions for maximum grafting have been optimized by varying the reaction variables, including the concentration of N-vinyl-2-pyrrolidone (12.0 × 10(--2) to 28 × 10(--2) mol dm(-3)), potassium bromate (6 × 10(-3) to 22 × 10(-3) mol dm(-3)), silver (2.4 × 10(-3)to 5.6 × 10(-3) mol dm(-3)), sulphuric acid (2.0 × 10(-3) to 10 × 10(-3) mol dm(-3)), gellan gum (0.6-1.4 g dm(-3)) along with time duration (60 to 180 min) and temperature (30-50 °C).Water swelling capacity, metal ion sorption and flocculation studies of synthesized graft copolymer have been performed with respect to the parent polymer. The graft copolymer has been characterized by FTIR spectroscopy and thermogravimetric analysis.

Graft copolymer of N-(hydroxymethyl) acrylamide with carboxymethylated guar gum was synthesized and the reaction conditions were optimized for better yield using potassium peroxymonosulfate and thiourea as a redox initiator. The optimum reaction conditions for grafting have also been determined by studying the effect of N-(hydroxymethyl) acrylamide, hydrogen ion, peroxymonosulphate, thiourea concentration and carboxymethylated guar gum along with time and temperature. Experimental results show that maximum grafting has been obtained at 1.4 g dm(-3) concentration of carboxymethylated guar gum and 16 x 10(-2) mol dm(-3) concentration of N-(hydroxymethyl) acrylamide. It has been observed that grafting ratio, add on, conversion, efficiency and rate of grafting increase up to 6.0 x 10(-3) mol dm(-3) of hydrogen ion, 2.4 x 10(-3) mol dm(-3) of thiourea, 14 x 10(-3) mol dm(-3) of peroxymonosulphate and 35 degrees C of temperature. Grafted copolymer has been characterized by FTIR spectroscopy and thermogravimetric analysis. Water swelling, flocculating, and metal ion uptake properties of partially carboxymethylated guar gum-g-N-(hydroxymethyl) acrylamide have been determined. (C) 2014 Published by Elsevier Ltd.

The present paper reports the graft copolymerization of N,N-dimethylacrylamide onto gellan gumby free radical polymerization using potassium peroxymonosulphate/sarbose redox system in an inert atmosphere. The reaction conditions for maximum grafting have been optimized by varying the reaction variables, including the concentration of N,N-dimethylacrylamide(4.0×10−2–20×10−2moldm−3), potassium peroxymonosulphate (0.6×10−2–1.4×10−2moldm−3), sarbose (0.4×10−3–3.6×10−3moldm−3), sulphuric acid (2.0×10−3–10×10−3moldm−3), gellan gum (0.6–1.4gdm−3) along with time duration (60–180min) and temperature (25–45°C).Water-swelling capacity, metal ion sorption and flocculation studies of synthesized graft copolymer have been performed with respect to the parent polymer. The graft copolymer has been characterized by FTIR spectroscopy and thermogravimetric analysis.

The graft copolymerization of N,N′-dimethylacrylamide onto guar gum initiated by potassium peroxymonosulphate/glycolic acid redox pair in an aqueous medium was studied gravimetrically under a nitrogen atmosphere. Grafting ratio, grafting efficiency and add on increase on increasing the concentration of potassium peroxymonosulphate (8.0×10−3 to 24.0×10−3moldm−3) and glycolic acid concentration (4.4×10−3 to 7.6×10−3moldm−3). On increasing the hydrogen ion concentration from 4×10−3 to 12.0×10−3moldm−3, grafting ratio, efficiency, add on and conversion were increased. Maximum grafting was obtained when guar gum and N,N′-dimethylacrylamide concentration were 1.0×10−2gdm−3 and 14.0×10−2moldm−3, respectively. An increase in temperature from 25°C to 45°C, the grafting ratio increases but conversion and homopolymer decrease. The optimum time period for graft copolymerization was 2h. The graft copolymers were characterized by IR spectroscopy and thermogravimetric analysis.

The aim of the paper is to study the physico-chemical phenomenon of synthesized graft copolymer (carboxymethylated guar gum-g-vinylsulfonic acid). The reaction optimum conditions for grafting has also been determined by studying the effect of vinylsulfonic acid, hydrogen ion, peroxymonosulphate, glycolic acid concentration and carboxymethylated guar gum along with time and temperature. Experimental results show that maximum grafting has been obtained at 1.8 g dm(-3) concentration of partially carboxymethylated guar gum and 5.3 x 10(-2) mol dm(-3) concentration of vinylsulfonic acid. It has been observed that grafting ratio, add on, conversion, efficiency increase up to 4.0 x 10(-3) mol dm(-3) of hydrogen ion, 4 x 10(-3) mol dm(-3) of glycolic acid, 14 x 10(-3) mol dm(-3) of peroxymonosulphate and 35 degrees C of temperature. Grafted copolymer has been characterized by FTIR spectroscopy and thermogravimetric analysis. Water swelling, flocculating, metal ion uptake and resistance to biodegradability properties of partially carboxymethylated guar gum-g-vinylsulfonic acid have been determined. (C) 2013 Elsevier Ltd. All rights reserved.

The synthesis of graft copolymer [κ-carrageenan-g-N-(hydroxymethyl) acrylamide] is carried out in nitrogen atmosphere using potassium peroxymonosulphate (PMS) and glycolic acid (GA) as redox system. The effect of reaction variables including the concentration of N-(hydroxymethyl) acrylamide (4 × 10(-2) to 36 × 10(-2))mol dm(-3), PMS (4 × 10(-3) to 20 × 10(-3))mol dm(-3), GA (1.6 × 10(-3) to 4.8 × 10(-3)) mol dm(-3), sulphuric acid (4 × 10(-3) to 12 × 10(-3)) mol dm(-3), κ-carrageenan (0.6-1.8) g dm(-3) as well as time duration (60-180)min and temperature (25-45)°C has been studied. The physicochemical properties of graft copolymer synthesized have been performed in terms of water swelling, metal ion sorption and flocculation with respect to the κ-carrageenan as a parent polymer. The graft copolymer has been characterized by FTIR and thermogravimetic analysis.

A graft copolymer of κ-carrageenan and 2-acrylamidoglycolic acid (CgOH-g-AGA) was synthesized via free radical polymerization initiated by potassium peroxymonosulphate/malonic acid redox pair. For affording maximum percentage of grafting, optimum conditions were determined by varying the concentrations of κ-carrageenan, 2-acrylamidoglycolic acid, potassium peroxymonosulphate, malonic acid, hydrogen ion, time and temperature. The swelling, metal ion uptake and flocculation studies were investigated with water, three metals (Ni2+, Pb2+ and Zn2+) solutions, coal (coking and non-coking) suspensions, respectively. Both, polymer backbone and its corresponding graft copolymer samples were characterized by Fourier transform infrared spectroscopy and thermogravimetric analysis.

The present paper reports the graft copolymerization of 2-acrylamidoglycolic acid onto chitosan by using potassium bromate/silver nitrate as an efficient redox initiator in an inert atmosphere. The effect of reaction conditions on grafting parameters i.e. grafting ratio, efficiency, conversion, add on, homopolymer and rate of grafting has been studied. Experimental results show that maximum grafting has been obtained at 0.4 g dm−3 concentration of chitosan, 8.0 × 10−2 mol dm−3 concentration of 2-acrylamidoglycolic acid and 1.0 × 10−3 mol dm−3 concentration of hydrogen ion. It has also been observed that grafting ratio, add on, conversion, efficiency and rate of grafting increase up to 3.2 × 10−3 mol dm−3 of silver nitrate and 1.7 × 10−2 mol dm−3 of potassium bromate. Time (120 min) and temperature (40 °C) were kept constant during reaction. The physicochemical properties of graft copolymer synthesized have been performed in terms of water swelling, metal ion sorption, flocculation and resistance to biodegradability with respect to the chitosan as a parent polymer. The graft copolymer has been characterized by Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis.

Graft copolymer of partially carboxymethylated guar gum (CMGOH) and N-vinylformamide (NVF) was synthesized by free radical polymerization using 2,2-Azobis [2-(2-imadazolin-2-yl) propane] dihydrochloride (AIPH) as initiator. The effect of various reaction parameters such as concentration of NVF, CMGOH, sulphuric acid and AIPH, as well as reaction time and temperature were investigated, and the grafting conditions were optimized. Percent total conversion, % grafting, grafting efficiency (%) and percent add on under different conditions were evaluated and compared. The reaction mechanism for graft copolymerization discussed. Studies on swelling, metal ion uptake and flocculation properties were carried out in aqueous medium and the results obtained are presented and discussed. Both CMGOH and its corresponding graft copolymer samples were characterized by Fourier transform infrared spectroscopy and thermogravimetric analysis. Looking at the reasonable results obtained, the synthesized graft copolymers CMGOH-g-NVF, may be exploited as potential candidates for some industrial important applications as flocculent superabsorbent, and other similar applications.

The graft copolymer of N-vinylformamide with alginic acid was synthesized by free radical polymerization using potassium peroxymonosulphate and thiourea as redox pair in inert atmosphere. The optimum conditions for maximum grafting have been determined by varying the concentrations of N-vinylformamide, potassium peroxymonosulphate, thiourea, sulfuric acid, alginic acid as well as time duration and temperature. The grafting parameters increase up to the certain concentrations of N-vinylformamide, potassium peroxymonosulhate, thiourea, and hydrogen ion while thereafter grafting parameters decrease. The effect of alginic acid concentration on grafting parameters has been observed to decrease continuously. It has also been found that grafting parameters increase up to certain time and temperature, respectively, and thereafter decrease. The swelling properties of graft copolymer in terms of swelling ratio and percent swelling are investigated. Flocculation property of pure and grafted sample for both coking and noncoking coals is also investigated for the treatment of coal mine waste water. The graft copolymer has been characterized by Fourier transform infrared spectroscopy as well as thermogravimetic analysis. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 121: 1400-1407, 2011

The synthesis of graft copolymer (partially carboxymethylated guar gum-g-N-vinyl-2-pyrrolidone) is carried out in nitrogen atmosphere using potassium peroxymonosulphate and glycolic acid as redox system. The effect of reaction variables including the concentration of N-vinyl-2-pyrrolidone (8 × 10 −2 to 24 × 10 −2 ) mol dm −3 , potassium peroxymonosulphate (6 × 10 −3 to 22 × 10 −3 ) mol dm −3 , glycolic acid (0.6 × 10 −3 to 4.0 × 10 −3 ) mol dm −3 , sulphuric acid (1 × 10 −3 to 3 × 10 −3 ) mol dm −3 ), partially carboxymethylated guar gum (0.6–1.4) g dm −3 as well as time duration (60–180) min and temperature (30–50) °C has been studied. The water swelling capacity of graft copolymer is investigated. Flocculation property for both coking and non-coking coals is studied for the treatment of coal mine waste water. The graft copolymer has been characterized by Fourier transform infrared spectroscopy and thermogravimetic analysis.

The synthesis of graft copolymer (κ-carrageenan-g-vinylsulfonic acid) is carried out in nitrogen atmosphere using potassium peroxymonosulfate (PMS) and malonic acid (MA) as redox system. The effect of reaction variables including the concentration of vinylsulfonic acid 1.3×10(-2) to 6.7×10(-2) mol dm(-3), PMS 4×10(-3) to 20×10(-3) mol dm(-3), MA 1.6×10(-3) to 4.8×10(-3) mol dm(-3), sulfuric acid 1×10(-3) to 8×10(-3) mol dm(-3), κ-carrageenan 0.4-1.8 g dm(-3) as well as time duration 60-180 min and temperature 25-45 °C has been studied. The water swelling capacity of graft copolymer is investigated. Flocculation property for both coking and non-coking coals is studied for the treatment of coal mine waste water. The graft copolymer has been characterized by FTIR and thermogravimetric analysis.

To synthesize a hydrolyzed graft copolymer, the reaction conditions have been optimized to afford maximum grafting followed by maximum absorbency by varying the concentrations of methacrylic acid (from 8×10−2 to 24×10−2moldm−3), potassium peroxymonosulphate (from 0.4×10−2 to 2.0×10−2moldm−3), silver nitrate (from 1.2×10−3 to 4.4×10−3moldm−3), hydrogen ion (from 1.0×10−3 to 9.0×10−3moldm−3) and partially carboxymethylated guar gum (from 0.4 to 1.8gdm−3) along with N,N′-methylene bisacrylamide (3.0×10−3 to 7.0×10−3moldm−3). The optimum time and temperature for grafting were found to be 40°C and 120min, respectively. The saponification reaction of graft copolymer synthesized has been carried out using NaOH (1.5–3.5N). The effect of methacrylic acid and N,N′-methylene bisacrylamide concentrations on swelling ratio for graft copolymer synthesized i.e. partially hydrolyzed graft copolymer (H-CmgOH-g-MAA) is investigated in water. The graft copolymer is characterized by Fourier transform infrared spectroscopy and thermogravimetric analysis.

The present paper reports the graft copolymerization of vinyl sulfonic acid onto sodium carboxymethyl cellulose by free radical polymerization using potassium peroxydiphosphate/thiourea redox system in an inert atmosphere. The reaction conditions for maximum grafting have been optimized by varying the concentration of vinyl sulfonic acid (2.6 × 10−2–8.0 × 10−2 mol dm−3), potassium peroxydiphosphate (4.0 × 10−2–20 × 10−2 mol dm−3), thiourea (0.8 × 10−3–4.0 × 10−3 mol dm−3), sulphuric acid (1.0 × 10−3–6 × 10−3 mol dm−3), sodium carboxymethyl cellulose (0.6–1.6 g dm−3) along with time duration (60–180 min) and temperature (30–50 °C). Water swelling capacity, metal ion sorption, flocculation studies and resistance to biodegradability of synthesized graft copolymer have been performed with respect to the parent polymer. The graft copolymer has been characterized by FTIR spectroscopy and thermogravimetric analysis.

The optimum conditions for maximum grafting have been determined by varying the concentrations of N-vinyl-2-pyrrolidone, hydrogen ion, potassium bromate, silver nitrate, chitosan along with time and temperature. The grafting ratio increased on increasing N-vinyl-2-pyrrolidone concentration and reaches maximum value at 20×10−2moldm−3. Similarly, the concentration of hydrogen ion increases, the grafting parameters increase and attain maximum value at 1.8×10−2moldm−3. The grafting parameters increase continuously on increasing the concentration of potassium bromate from 2×10−3moldm−3 to 10×10−3moldm−3. On increasing silver nitrate concentration from 0.4×10−2 to 3.6×10−2moldm−3, grafting ratio is found to be maximum at 2.8×10−2moldm−3. The grafting parameters decrease continuously on increasing the concentration of chitosan. An attempt has been made to study some of the physicochemical properties in terms of swelling, metal ion sorption and flocculation. The chitosan and chitosan-g-N-vinyl-2-pyrrolidone were characterized by infrared spectroscopy and thermogravimetric analysis.

The present paper reports the modification of alginate through the grafting of 2-acrylamidoglycolic acid by free radical polymerization using an efficient potassium peroxydiphosphate/silver nitrate redox system in an inert atmosphere. The reaction conditions for maximum grafting have been optimized by varying the reaction variables including the concentration of 2-acrylamidoglycolic acid (2.0×10−2–7.3×10−2moldm−3), potassium peroxydiphosphate (0.4×10−2–2.0×10−2moldm−3), silver nitrate (1.2×10−3–4.4×10−3moldm−3), sulphuric acid (1.0×10−3–8×10−3moldm−3), alginate (0.4–1.8gdm−3) along with time duration (60–180 min) and temperature (30–50°C). Water swelling capacity, metal ion sorption, flocculation and resistance to biodegradability studies of synthesized graft copolymer have been performed with respect to the parent polymer. The graft copolymer has been characterized by Fourier transform infrared spectroscopy and thermogravimetric analysis.

Alginate-g-vinyl sulfonic acid graft copolymer was synthesized through the graft copolymerization of vinyl sulfonic acid (VSA) onto alginate with an efficient system, i.e., potassium peroxydiphosphate (PDP)/thiourea in an aqueous medium. The effects of the concentration of thiourea, PDP, hydrogen ion, alginate, and VSA along with the time and temperature on the graft copolymerization were studied by the determination of the grafting parameters (grafting ratio, add-on, conversion, grafting efficiency, and homopolymer). The synthesized graft copolymer was characterized by FTIR analysis. Thermogravimetric analysis showed that the alginate-g-vinyl sulfonic acid is thermally more stable than alginate. Water swelling capacity, metal ion sorption, flocculation, and resistance to biodegradability studies of synthesized graft copolymer have been performed with respect to the parent polymer. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 118: 3685-3694, 2010

The optimum conditions for grafting of N-vinyl-2-pyrrolidone onto alginate initiated by potassium peroxymonosulphate/glycolic acid redox initiator have been determined by varying the concentration of N-vinyl-2-pyrrolidone, hydrogen ion, potassium peroxymonosulphate, glycolic acid, alginate along with time and temperature. Experimental results show that maximum grafting has been obtained at 0.1gdm−3 concentration of alginate and 16×10−2moldm−3 concentration of N-vinyl-2-pyrrolidone. It has been observed that grafting ratio, add on, conversion and efficiency increase up to 5.0×10−3moldm−3 of hydrogen ion, 2.8×10−3moldm−3 of glycolic acid, 12×10−3moldm−3 of potassium peroxymonosulphate and 40°C of temperature. A physicochemical phenomenon in terms of swelling, metal-ion uptake and flocculation has also been studied and it has been found that graft copolymer shows enhancement in these properties than pure alginate. Both, grafted and ungrafted samples have been characterized by FTIR-Spectroscopy and thermogravimetric analysis.

κ-Carrageenan-g-N-vinyl formamide was synthesized by free radical initiation using the potassium monopersulphate (PMS)/malonic acid redox pair in an inert atmosphere. The effects of variation of different reactant on grafting parameters have been studied by varying the concentration. Grafting ratio, add on and conversion showed an increasing trend on increasing the concentration of N-vinyl formamide, malonic acid, κ-carrageenan and the concentration of PMS from 6 × 10−3 to 22 × 10−3 mol dm−3. The optimum temperature and time for grafting of N-vinyl formamide onto κ-carrageenan was found to be 40 °C and 120 min, respectively. The metal ion sorption, swelling behaviour, flocculation and resistance to biodegradation properties have been studied. Flocculation capability of κ-carrageenan and κ-carrageenan-g-N-vinyl formamide for both coking and non-coking coals has been studied for the treatment of coal mine waste water. The graft copolymer was characterized by FT-IR spectroscopy and thermogravimetric analysis.

An unreported graft copolymer of 2-acrylamidoglycolic acid with partially carboxymethylated guar gum has been synthesized under nitrogen atmosphere using peroxymonosulphate/thiourea redox pair at 40°C. The effect of reaction conditions on grafting parameters i.e., grafting ratio, efficiency, conversion, add on, homopolymer and rate of grafting has been studied. Experimental results show that maximum grafting has been obtained at 0.1gdm−3 concentration of partially carboxymethylated guar gum and 5.3×10−2moldm−3 concentration of 2-acrylamidoglycolic acid. It has been observed that grafting ratio, add on, conversion, efficiency and rate of grafting increase up to 5.0×10−3moldm−3 of hydrogen ion, 2.4×10−3moldm−3 of thiourea, 10×10−3moldm−3 of peroxymonosulphate and 40°C of temperature. Grafted copolymer has been characterized by FTIR spectroscopy and thermogravimetric analysis. Physico-chemical properties of partially carboxymethylated guar gum-g-2-acrylamidoglycolic acid have been determined.