Binary Vinyl Monomer Research Articles

Synthesis and characterization of cellulose based graft copolymers with binary vinyl monomers for efficient removal of cationic dyes and Pb(II) ions

Cellulose grafted with 2-acrylamido-2-methylpropane sulfonic acid (AASO3H) and binary comonomer acrylonitrile (AN) were synthesized and characterized by FTIR, XRD, SEM, TGA/DTA and swelling studies. Adsorption parameters like contact time, temperature, pH and concentration were optimized for maximum adsorption of organic dyes and Pb(II) ions. Dye adsorption behavior studied for cationic malachite green (MG) and crystal violet (CV) dyes followed the order Cell-g-AASO3H > Cell-g-AASO3H-co-AN > cellulose. Order for adsorption of dyes were reported as MG > CV. Pseudo-second-order model is best-fitted with the experimental data and adsorption capacity from Langmuir adsorption isotherm for MG, and CV were 61.46 and 55.71 mg.g−1 respectively, for Cell-g-AASO3H. Percent uptake capacities followed the order Cell-g-AASO3H-co-AN > Cell-g-AASO3H > cellulose for Pb(II) ions. Maximum adsorption capacities for Pb(II) ions from Langmuir adsorption isotherm were 154.32 and 181.49 mg.g−1 for Cell-g-AASO3H and Cell-g-AASO3H-co-AN, respectively.

Removal of organic dyes and metal ions by cross-linked graft copolymers of cellulose obtained from the agricultural residue

Cellulose extracted from agricultural residue, rice husk was functionalized through free radical grafting with a binary vinyl monomer mixture of 2-acrylamido-2-methylpropane sulfonic acid and acrylic acid in the presence of N,N'-methylene bisacrylamide cross-linker. To ascertain the grafting, the synthesized copolymer, Cell-g-AASO3H-co-AAc was characterized by FESEM, FTIR, XRD and thermal analytical techniques. The swelling behavior of the grafted copolymer, analyzed as a function of pH followed the order 7.0 > 9.4 > 2.2. The as-synthesized graft copolymer was used as an adsorbent for the removal of model malachite green, crystal violet, congo red dyes and Ni(II) and Cu(II) metal ions from aqueous solutions. The adsorption characteristics of the grafted copolymer were studied as a function of contact time, temperature, pH, and concentration. Cationic dyes were adsorbed maximum at pH 7.0 in 90 min contact time, whereas anionic dye was removed under acidic pH of 2.2 in 8 h. Maximum adsorption of Ni(II) and Cu(II) ions was observed at pH 6.0 and temperature of 30 °C after a contact time of 120 min. Among the various kinetic and adsorption isotherm models, the experimental adsorption data were best fitted in pseudo-second-order kinetic model and Langmuir isotherm model for organic dyes and metal ions. From Langmuir adsorption isotherm, maximum sorption capacities of 112.74 and 109.77 mg/g was reported for Ni(II) and Cu(II) ions, respectively. The current study thus proves that the Cell-g-AASO3H-co-AAc copolymer can efficiently be used as an adsorbent for uptake of harmful cationic as well as anionic dyes and toxic metal ions from industrial wastewater.

Metal ions and organic dyes sorption applications of cellulose grafted with binary vinyl monomers

Metal ions and dyes sorption applications of Cell-g-AASO3H-co-GMA were studied, herein. The adsorbent Cell-g-AASO3H-co-GMA was synthesized through grafting of 2-acrylamido-2-methylpropane sulfonic acid (AASO3H) and binary comonomer glycidyl methacrylate (GMA) using potassium persulfate (KPS) as free radical chemical initiator and N,N′-methylene bisacrylamide (NMBA) as cross-linker onto the cellulose extracted from agricultural waste rice husk. The graft copolymer was characterized for morphological, structural, compositional, crystalline and thermal properties through different characterization techniques like FTIR, FESEM, XRD, and TGA/DTA. The swelling behavior of the graft copolymer was evaluated at 2.2, 7.0 and 9.4 pH and compared with the pristine cellulose to explore their applications for the sorption of metal ions and dyes from their aqueous solutions. The adsorption parameters were elaborated for model cationic malachite green (MG) and crystal violet (CV) dyes, anionic congo red (CR) dye and Ni2+ and Cu2+ ions. The adsorption of dyes and metal ions was investigated as a function of contact time, temperature, pH and concentration. The mechanism of the adsorption and the interactions between adsorbent Cell-g-AASO3H-co-GMA and different adsorbates were studied using different kinetics and adsorption isotherms models. The adsorption data for dyes and metal ions fitted well with the pseudo-second-order rate equation and Langmuir adsorption isotherm. The maximum adsorption capacity of Cell-g-AASO3H-co-GMA, obtained from the Langmuir adsorption isotherm for MG, CV and CR dyes were 46.232, 53.533 and 20.942 mg g−1, whereas for Cu2+ and Ni2+ ions it was 78.247 and 69.061 mg g−1 respectively.

Sorption of Pb(II), Cu(II), Fe(II) and Cr(VI) metal ions onto cross-linked graft copolymers of chitosan with binary vinyl monomer mixtures

Novel adsorbents for sorption of Pb(II), Cu(II), Fe(II) and Cr(VI) metal ions from waste water were synthesized by simultaneous cross-linking and graft copolymerization of chitosan (Ch) with N-isopropyl acrylamide (NIPAM) and its binary comonomers acrylic acid, acrylamide and acrylonitrile in presence of azo-bis(isobutyronitrile) (AIBN) as free radical initiator and N,N′-methylene bisacrylamide (MBA) cross-linker. FTIR, XRD, SEM and TGA/DTA techniques were used to describe the structural aspects of cross-linked graft copolymers. The improvement in swelling properties of the synthesized hydrogels was utilized to explore their potential for sorption of toxic metal ions from aqueous solutions. Metal ion sorption by synthesized cross-linked adsorbents was studied as a function of the change in contact time, pH, temperature and concentration of metal ions from a solution of individual metal ions. Selective sorption of metal ions was performed by immersing polymeric samples in a solution containing four metal ions in the same concentration. Candidate polymers showed preferential sorption of metal ions in order of Cu(II)>Pb(II)>Fe(II)>Cr(VI) ions. Cross-Ch-g-poly(NIPAM-co-AAc), Cross-Ch-g-poly(NIPAM-co-AAm) and Cross-Ch-g-poly(NIPAM), showed best results for sorption of all ions from single and four component solutions.

Selective sorption of Fe(II) ions over Cu(II) and Cr(VI) ions by cross-linked graft copolymers of chitosan with acrylic acid and binary vinyl monomer mixtures

Low-cost and environment-friendly polymeric adsorbents for sorption of heavy metal ions were synthesized by simultaneous graft copolymerization and cross-linking of acrylic acid alone and with comonomers glycidyl methacrylate, acrylamide and acrylonitrile onto chitosan using free radical initiator and cross-linker in aqueous medium. Structural aspects of cross-linked graft copolymers have been characterized by FTIR, SEM, TGA/DTA, XRD and swelling behavior at pH 2.2, 7.0 and 9.4. An attempt has been made to study sorption of Cr(VI), Cu(II) and Fe(II) ions on cross-linked graft copolymers by equilibration method and to establish a relationship between structural aspects of graft copolymers and metal ion uptake efficiency and selectivity. Solutions of individual ions were used for non-competitive sorption onto synthesized bio-adsorbents as a function of change in contact time, temperature, pH and metal ion concentration in feed. Competitive sorption investigation was performed from an aqueous solution of ternary metal ions by batch equilibration at 25°C and at 7.0pH. Cross-linked graft copolymers showed better results than unmodified chitosan and showed preferential sorption of Fe(II) ions than Cu(II) and Cr(VI) ions.

Synthesis and characterization of PET fibers grafted with binary mixture of 2-methylpropenoic acid and acrylonitrile by free radical: its application in removal of cationic dye

Grafting of binary vinyl monomer mixtures such as 2-methylpropenoic acid (MPA) and acrylonitrile (AN) onto poly (ethylene terephthalate) fibers (PET) was achieved in an aqueous medium with using benzoyl peroxide like free radical initiator. A new reactively fibrous adsorbent was used for removal of dye such as methylene blue (MB) from aqueous media through batch sorption method. Fibers adsorbent was swelled in solution to support the graft and the subsequent polymerization of MPA/AN onto polyester fibers. Optimum conditions for grafting were discovered and reactive fiber were characterized. Variations of graft yield with time, temperature, initiator concentration and monomer mixture ratio were investigated. The optimum initiator concentration was found to be 8 × 10−3 mol/L. The percentage of grafting rose steadily with the vinyl monomer mixture monomer concentration (50 %). The optimum temperature and polymerization time were found to be 80 °C and 120 min, respectively. The use of AN and MPA monomers together in grafting produce a significant increased in the graft yield. Experimental studies showed that the percentage removal of MB was a great higher on the MPA/AN grafted PET (MPA/AN-g-PET) fibers than on the original PET fibers. The adsorbed quantity of MB improved with pH and basic pH was appropriate for the elimination of MB. MPA/AN-g-PET fibers removed 98 % of cationic dye when initial concentration diverse from 10 to 80 mg L−1 at pH 9.0. Almost all of the adsorbed cationic dye was eluted by ethanoic acid in methanol. Ten removal–desorption cycles indicated that the reactive fibers were favorable for repetitive use without notable change in removal capacity. Consequently, the MPA/AN-g-PET fibers have demonstrated potential as an effective adsorbent for the extremely effective removal of cationic dyes from aqueous media.

Synthesis and Characterization of Chitosan Based Graft Copolymers with Binary Vinyl Monomers for Controlled Drug Release Application

Synthesis and Characterization of Chitosan Based Graft Copolymers with Binary Vinyl Monomers for Controlled Drug Release Application

Microwave induced synthesis of graft copolymer of binary vinyl monomer mixtures onto delignified Grewia optiva fiber: application in dye removal.

Grafting method, through microwave radiation technique is very effective in terms of time consumption, cost effectiveness and environmental friendliness. Via this method, delignified Grewia optiva identified as a waste biomass, was graft copolymerized with methylmethacrylate (MMA) as an principal monomer in a binary mixture of ethyl methacrylate (EMA) and ethyl acrylate (EA) under microwave irradiation (MWR) using ascorbic acid/H2O2 as an initiator system. The concentration of the comonomer was optimized to maximize the graft yield with respect to the primary monomer. Maximum graft yield (86.32%) was found for dGo-poly(MMA-co-EA) binary mixture as compared to other synthesized copolymer. The experimental results inferred that the optimal concentrations for the comonomers to the optimized primary monomer was observed to be 3.19 mol/L × 10−1 for EMA and 2.76 mol/L × 10−1 for EA. Delignified and graft copolymerized fiber were subjected to evaluation of physicochemical properties such as swelling behavior and chemical resistance. The synthesized graft copolymers were characterized with Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and X-ray diffraction techniques. Thermal stability of dGo-poly(MMA-co-EA) was found to be more as compared to the delignified Grewia optiva fiber and other graft copolymers. Although the grafting technique was found to decrease percentage crystallinity and crystallinity index among the graft copolymers but there was significant increase in their acid/base and thermal resistance properties. The grafted samples have been explored for the adsorption of hazardous methylene dye from aqueous system.

Application of vinyl monomers functionalized cellulosic biopolymer for removal of dissolved toxic metal ions from polluted water samples

In the present study, a binary vinyl monomer mixture of acrylonitrile (AN) and acrylamide (AAm) was graft copolymerized onto cellulosic fibers using ascorbic acid and hydrogen peroxide as redox initiator. The grafted fibers were further reacted with aqueous solution of hydroxylamine hydrochloride at pH 10.0 to convert them into amidoxime derivative. These resulting functionalized cellulosic fibers were characterized by various techniques such as FT-IR, TGA, and SEM studies. The functionalized fibers were used for removal of toxic metal ions from aqueous solution through adsorption process. The adsorption process follows pseudo-second-order kinetics and relative adsorption rate of various metal ions were found in the order of Pb2+>Zn2+>Cd2+. Langmuir, Freundlich and Dubinin–Radushkevich models were used to show the adsorption isotherm. Langmuir model fits better with the equilibrium data. The maximum monolayer capacity qm calculated using the Langmuir isotherm for Zn2+, Cd2+ and Pb2+ metal ions were 55.72, 106.72 and 200mg/g respectively. From thermodynamic parameters ΔH° and ΔG° values were obtained. The adsorption process has been found to be exothermic in nature.

Synthesis and Characterization of Graft Co-Polymers of Sisal Fiber with Binary Vinyl Monomers

In this paper morphological transformation of sisal fiber by graft copolymerization with methyl acrylate and its binary mixture with acrylic acid (AAc), vinyl acetate (VA) and n-butyl acrylate (BuA), using FAS-KPS initiator, under influence of microwave radiations has been reported. Optimum reaction conditions for maximum graft yield were kept same as that in case of grafting of principal monomer. Maximum grafting has been observed in case of sisal-g-poly(MA+VA). The Graft copolymers thus formed were characterized with SEM, TGA and XRD techniques. Thermal stability has been found to increase and percentage crystallinity and crystallinity index decrease upon grafting.

Surface Modification Of Ramie Fibers Using Microwave Assisted Graft Copolymerization Followed By Brevibacillus Parabrevis Pretreatment

Ramie fibers usually display poor interfacial adhesion when reinforced in hydrophobic polymer matrices. Hydrophilic nature of natural fibers becomes the most crucial issue in composites engineering. Surface modification of natural fibers has been found to be very effective in improving the fiber-matrix adhesion. In the present paper, we have reported the microwave assisted grafting of binary vinyl monomer mixtures on to ramie fibers (Boehmeria nivea) and bacterial cellulase assisted pre-treatment of ramie fibers using bacteria Brevibacillus parabrevis. The effects of these pretreatments on some properties of ramie fibers are discussed in the present paper. The modified fibers were characterized by scanning electron microscopy (SEM), X-ray diffraction, and TGA/DTA techniques to determine their morphology, crystallinity and thermal stability. Surface of ramie fiber becomes rough on grafting with synthetic polymers, whereas biologically modified ramie fibers showed the enhanced softness and smooth appearance due to the removal of gum materials and other impurities from the surface of fibers. Both the treatments have slightly changed the thermal stability and crystallinity of ramie fibers.

Development and assessment of the advanced graft copolymers obtained from Hibiscus sabdariffa biomass

AbstractIn this article, the morphological transformation in Hibiscus sabdariffa stem fiber through graft copolymerization with effective ethyl acrylate (EA) and its binary vinyl monomeric mixtures using ceric ammonium nitrate—nitric acid initiator system has been reported. Different reaction parameters such as temperature, time, initiator concentration, monomer concentration, and pH were optimized to obtain the maximum graft yield (117.3%). The optimized reaction parameters were then used to screen the additive effect of EA with n‐butyl acrylate (BA), acrylic acid (AA), and 4‐vinyl pyridine (4‐VP) in binary vinyl monomer mixtures on percentage grafting, properties, and the behavior of the fiber. The graft copolymers were characterized by FTIR, SEM, XRD, TGA, and DTA techniques and evaluated for physico‐chemical changes. With increase in the Pg a significant physico‐chemico‐thermal resistance, miscibility in organic solvents, hydrophobicity were found to increase, whereas crystallinity, crystallinity index, dye‐uptake, and hydrophylicity decreased, however, the cellulose form I remained unchanged. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Microwave‐enhanced synthesis of graft copolymer of binary vinyl monomer mixtures onto acetylated Saccharum spontaneum L and characterization

AbstractSynthesis of graft copolymer under the influence of microwave radiation is a rapid, efficient, clean, cheap, convenient, energy‐saving, and green method. Grafting of methylmethacrylate (MMA) + acrylamide (AAm), MMA + acrylonitrile (AN), and MMA + acrylic acid (AA) binary mixtures onto acetylated Saccharum spontaneum L was carried out under the influence of microwave radiation (MWR), and maximum graft yield 94.5% was found with MMA + AAm binary mixture. Synthesized graft copolymers were characterized with FT‐IR, scanning electron microscopy, TGA/DTA/DTG, and X‐ray diffraction techniques. Thermal stability of Ss‐g‐poly(MMA + AAm) was found to be more than that of acetylated S. spontaneum fiber and other graft copolymers. Although on grafting, percentage crystallinity and crystallinity index decreased but graft copolymers were found to exhibit more moisture, chemical, and thermal resistance. © 2011 Wiley Periodicals, Inc. Adv Polym Techn 30: 122–137, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.20209

Synthesis of graft copolymers of binary vinyl monomer mixtures onto acetylated Saccharum spontaneum L and characterization

AbstractMethylmethacrylate (MMA) + acrylamide (AAm), MMA + acrylonitrile (AN), and MMA + acrylic acid (AA) binary vinyl monomer mixtures were graft copolymerization onto acetylated Saccharum spontaneum L, was carried out and maximum graft yield (185.6 %) was found with MMA+AAm binary mixture. Synthesized graft co‐polymers were characterized with FT‐IR spectrophotometry, scanning electron microscopy (SEM), thermal analysis TGA/DTA/DTG, and X‐ray diffraction (XRD) techniques. Thermal stability of Ss‐g‐poly(MMA + AAm) was found to be more than that of natural, acetylated S. spontaneum fiber and other graft copolymers. Although on grafting, percentage crystallinity and crystallinity index were found to decrease but graft copolymers were found to exhibit more moisture, chemical, and thermal resistance. Also, it can be observed that the surface of the grafted fibers is highly rough in comparison with the ungrafted fiber. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

SYNTHESIS OF FLAX-G-COPOLYMERS UNDER PRESSURE FOR USE IN PHENOLIC COMPOSITES AS REINFORCEMENT

In present paper, binary vinyl monomers mixtures such as methyl methacrylate (MMA) + vinyl acetate (VA), MMA + acrylamide (AAm) and MMA + styrene (Sty) have been graft copolymerized onto flax fiber. 21.32, 38.80 and 25.60 % grafting have been found with MMA+VA, MMA+AAm and MMA+Sty binary monomer mixtures, respectively. Graft copolymers thus prepared were characterized with FTIR spectroscopy, scanning electron microscopy (SEM), TGA/DTA techniques and X-ray diffraction (XRD). Thermal stability of flax-g-poly(MMA+AAm) has been found to more than that of flax fiber and other graft copolymers. On grafting, percentage crystallinity decreases rapidly with reduction in its stiffness and hardness. Highest value of percentage crystallinity has been found in case of flax fiber in comparison to flax-g-copolymers. Synthesized graft copolymers were used as reinforcing material in phenolic composites. Composites thus prepared were subjected for the evaluation of some mechanical properties such as wear resistance, tensile strength and compressive strength.

Induction of Morphological Changes in Hibiscus sabdariffa Fiber on Graft Copolymerization with Binary Vinyl Monomer Mixtures

Various reaction parameters of the graft copolymerization of Hibiscus sabdariffa fiber with methyl acrylate as principal monomer and its binary mixture with acrylonitrile, acrylic acid, and acrylamide were optimized. The graft copolymers obtained were characterized by XRD, TGA-DTA, SEM, and FT-IR techniques and were evaluated for different physicochemical changes like moisture absorption and chemical resistance against 1 N NaOH and 1 N HCl. The percentage crystallinity and crystallinity index were found to decrease with increase in grafting, while there was reduction in moisture absorption and increase in chemical and thermal resistance of the graft copolymers.

A Study of Crystallinity of Graft Copolymers of Flax Fiber with Binary Vinyl Monomers

AbstractThe present paper deals with graft copolymerization of binary vinyl monomer mixtures onto flax fiber. Maximum grafting (86.02 %) has been found with MMA+EA binary mixture. Percentage crystallinity and crystallinity index of graft copolymers were measured with X-ray diffraction (XRD) technique. Crystallinity of flax decreases on grafting with binary vinyl monomer mixtures. Flax showed the highest value of percentage crystallinity (76.96 %) and crystallinity index (0.7005) in comparison to Flax-g-copolymers.

Potential use of graft copolymers of mercerized flax as filler in polystyrene composite materials

Graft copolymerization of binary vinyl monomers onto mercerized flax fiber was carried out for the enhancement of mechanical properties of polystyrene composites. Binary vinyl monomer mixture of AA+AN has been found to show maximum grafting (33.55%) onto mercerized flax. Graft copolymers thus synthesized were characterized with FT-IR spectroscopy, SEM, and TGA techniques. Mercerized flax (MF) showed maximum thermal stability in comparison to graft copolymers. It has been found that polystyrene composites reinforced with graft copolymers showed improvement in mechanical properties such as wear resistance, compressive strength, and tensile strength.

Preparation of microwave radiation induced graft copolymers and their applications as reinforcing material in phenolic composites

AbstractFlax fiber was modified through grafting of binary vinyl monomers mixtures such as methyl methacrylate (MMA)/vinyl acetate (VA), MMA/acrylamide (AAm), and MMA/styrene (Sty) under the influence of microwave radiations. 24.64% grafting was found at 210 W microwave power under optimum reaction conditions. Graft copolymers obtained were characterized with FTIR spectroscopy, scanning electron microscopy, and TGA/DTA techniques. Graft copolymers were found to be moisture retardant with better tensile strength. Phenolic composites using graft copolymers vis‐à‐vis flax as reinforcing material were subjected for the evaluation of different mechanical properties such as wear resistance, tensile strength, compressive strength, modulus of rupture (MOR), modulus of elasticity (MOE), and stress at the limit of proportionality (SP). Composites reinforced with graft copolymers showed better mechanical properties in comparison to composites reinforced with flax. Phenolic composites reinforced with Flax‐g‐poly(MMA/Sty) showed maximum wear resistance followed by reinforcement with flax, Flax‐g‐poly (MMA/AAm), and Flax‐g‐poly(MMA/VA). Composites reinforced with Flax‐g‐poly(MMA/Sty) and flax fibers have been found to show 150 N tensile strength with extension of 3.94 and 2.17 mm, respectively. It has also been found that composites reinforced with Flax‐g‐poly(MMA/Sty) showed maximum compressive strength (1,000 N) with compression of 3.71 mm in comparison to other graft copolymers and flax fibers reinforcement. Reinforcement of phenolic resin with Flax‐g‐poly(MMA/Sty) and flax fibers could improve the MOR and MOE. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers

Grafting of Flax Fiber (Linum usitatissimum) with Vinyl Monomers for Enhancement of Properties of Flax-Phenolic Composites

Binary vinyl monomers such as methylmethacrylate (MMA)/Ethylacrylate (EA), MMA/Acrylonitrile (AN) and MMA/Acrylic acid (AA) have been graft co-polymerized onto flax fibers under the influence of microwave radiations (MWR). Various reaction parameters have been optimized and maximum grafting (25%) was observed in reaction time of 30 min at 210 W microwave power. Flax-g-copolymers thus prepared were used as reinforcing material in the preparation of flax-phenolic composites. Wear resistance was maximum with reinforcement of Flax-g-poly(MMA/AA). Composites reinforced with Flax-g-poly(MMA/EA) showed better tensile strength and can bear load upto 225 N with extension of 3.28 mm and composites reinforced with Flax-g-poly(MMA/AA) showed better compressive strength and can bear load upto 1000 N with compression of 1.74 mm. Maximum values of MOR, MOE and SP were found to be 108.0 N/mm2, 5295.62 N/mm2 and 99.29 N/mm2 for the composites reinforced with Flax-g-poly(MMA/AA). On grafting of flax fibers with vinyl monomers, fibers become more and more moisture retardant. It has been found that strength of Flax-g-copolymers was found more than that of raw flax fibers. Flax-g-poly(MMA/AA) has been found to show good thermal stability in comparison to other graft co-polymers and raw flax fibers. Phenol-formaldehyde (PF) composites reinforced with graft co-polymers of flax fibers showed better mechanical properties in comparison to composites reinforced with raw flax fibers. Composites reinforced with Flax-g-poly(MMA/AA) showed the increased values of MOR, MOE and SP.