Papers by Keyword: Acrylamide

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Authors: Zhong Qing Zhang, Chi Zhang, Hong Lei, Ling Ling Zhao, Rui Huan Yang, Chuang Shuai, Ji Chao Chen, Peng Qu
Abstract: Rice husk is a plentiful agricultural byproduct. In this paper, rice husk (RH) surface was first treated by NaOH/urea into a modified-rice husk(MRH), then the MRH was used as a new template for polymerization of acrylamide(AM) on MRH, as a result, the product named as MRH-g-AM, was formed by the free-radical initiation in aqueous solution using ammonium persulfate as an initiator. The polymer grafted on the MRH was considered as a novel copolymer which was thereafter analyzed by FTIR and SEM. The product was washed thoroughly with distilled water to remove all unreactive chemicals. The results showed that MRH was successfully reacted with AM. The SEM images indicated that MRH-g-AM appeared distinct cracks and formed a loosen structure in comparison with RH, indicating the facilitation of heavy metal ion adsorption in the future wastewater treatment.
Authors: Xin Jian He, Kai Huang, Jian Jun Xie, Na Li, Nian Zeng
Abstract: A kaolin/sodium lignosulfonate graft acrylic acid and acrylamide superabsorbent composites(KLPAAM) prepared by solution polymerization are used for the equilibrium absorbency test of KLPAAM superabsorbent composite in different metal ion salt solutions. The effects of the solution concentrations on the equilibrium absorbencies in CuCl2, ZnCl2, FeCl3 and AlCl3 solutions are in order: CuCl2<ZnCl2<FeCl3<AlCl3. The solution concentrations and the pH values have an important effect on the equilibrium absorbencies. There are different pH values, 3.0 in FeCl3 and ZnCl2, 4.25 in AlCl3 and 6.0 in CuCl2 solution when the equilibrium absorbencies quickly increase with the pH values of the solutions. And then they reach their relative define values, in which the pH value is 3.8 in FeCl3, 3.5 in ZnCl2 and 5.5 in AlCl3 solution. The absorbency obviously increases again when the pH value is larger than 7.0 in ZnCl2 solution. They are slightly affected by the solution temperatures, that is, slightly decreases with increasing solution temperatures.
Authors: Sri Mulijani, Erizal, Tun Tedja Irawadi, Tyas Cipta Katresna
Abstract: Realizing the growing extraordinary interest in the development of polymer hydrogels, successful attempt has been made for synthesis of copolymer hydrogels from aqueous solution of acrylamide/bacterial cellulose (AAm/BC) with irradiation processing technology using Co-60 gamma source. The study envisaged to: (i) develop a novel high strength polymer nanocomposite hydrogels containing natural BC, and (ii) investigate chemical structure, morphology, and mechanical strength properties of the formed gels. The effectiveness of AAm/BC hydrogel for wound dressing application was also tested. Structure and properties of composite were investigated using Fourier Transform Infrared spectrophotometer (FTIR), Differential Scanning Calorimetry (DSC), and Atomic force microscopy (AFM). While investigating the influence of irradiation dose and concentration of acrylamide on gel content, swelling properties and thermal stability of copolymer hydrogel,maximum gel content of prepared hydrogel was obtained at the radiation dose of 40 kGy. Swelling ratio and equilibrium water content increased with increasing irradiation dose and concentration of acrylamide in feed solution. The water absorption of hydrogel increased with increased standing time in swelling medium. It was rapid up to 24 h and got slowed down thereafter. The water absorption also increased with increasing concentration of irradiation dose in the feed solution. The water absorption of copolymer hydrogel obtained at 40 kGy irradiation dose decreased from 1800 to 1400%. This type of diffusion of prepared hydrogel was found to be a non Fickian diffusion. The thermal stability of copolymer hydrogel prepared at the irradiation dose of 40 kGy increased with increasing amount of AAm in the feed solution. The mechanical behavior of composite hydrogels at optimum irradiation dose performed value of tensile and strain at 46.3MPa and 36.6%, respectively.
Authors: Zi Yi Wan, Ting Fei Xi, P. Zhao, Y. Sun, Z.G. Feng
Abstract: The polyacrylamide hydrogel (PAMG) has been used in cosmetology in China, Ukraine and Russia since 1990s. Because the monomer acrylamide(AM) used to produce PAMG has been implicated as a potential mutagen and reproductive toxicant[1,2], it is important to accurately determine the amount of residual AM monomer in the PAMG. In this study, a quick, practical and simple method to determine AM is presented with respect to the hydrogel. AM is analysed quantitatively by ODS-3 column with ultraviolet (UV) absorbance detector. AM is separated from interferential component with an aqueous solution of 0.9%NaCl (NS) adjusted at pH~3.7 using hydrochloric acid and then detected at a UV wavelength of 210 nm. The results show that ODS-3 is effective approach for quantifying AM concentrations in PAMG. This method has a lower detection limit of 0.003µg/ml and a linear response range of 0.003 and 0.9 µg/ml (depending on the range required for analysis). Precision studies give coefficients of variation of <3.2%(n=5) for 0.003µg/ml. The recoveries for this method are greater than 90%. When AM content in PAMG is lower than the detection limit of this method, SPE (solid phase extraction) could be used to concentrate AM. In the case, C18 cartridge is used. And the recoveries are about 70% for SPE when AM concentration is lower than ppb.
Authors: Jiao Lu, Bo Peng, Ming Yuan Li, Mei Qin Lin
Abstract: Dispersion polymerization of acrylamide and acrylic acid was successfully carried out in aqueous salt solutions using anionic polyelectrolytes as stabilizers. The influences of aqueous solution of salt concentration, molecular weight and concentration of the stabilizers on the apparent viscosity and stability of the dispersions, and on the molecular weight of the polymers prepared were investigated. The results showed that stable dispersions could be obtained on condition that salt concentration was between 26%~30%, concentration of stabilizers between 8%~12%, and intrinsic viscosity of stabilizers between 2.977~3.740 dL/g. With salt concentration ranging from 26% to 30%, molecular weight of products increased first and then decreased. Molecular weight of products was hardly changed when concentration of stabilizer was between 8%~12%. When intrinsic viscosity of stabilizer was between 2.977~3.740 dL/g, increase of the molecular weight of stabilizer resulted in a decrease in the molecular weight of the products.
Authors: Ming Qiu, Ren Song Hu, Ying Chun Li, Zhuo Pei Yang, Chuang Chuang Duan
Abstract: The effects of acrylamide modified liner on bonding properties and tribological properties of self-lubricating spherical plain bearings were explored by used of Instron5944 electronic universal testing machine and homemade spherical plain bearings friction and wear tester. The results showed that the bonding properties of bearings modified by acrylamide modified liner were much more improved than those of the unmodified bearings; Self-lubricating spherical plain bearing friction and wear properties and oscillating frequency obvious correlational dependence. With the increase of the oscillation frequency, the friction coefficient and the wear loss increased, while the friction temperature rose. The friction coefficient, wear loss and friction temperature of bearings modified were much more improved than those of the unmodified bearings. It showed that the liners after modification treatment can improve the tribological properties of self-lubricating spherical plain bearings.
Authors: Xiao Cui Dong, Ding Cao, Yan Shi, Zhi Feng Fu
Abstract: A novel nanofibrous membrane was used for removing Cu (II) from aqueous solutions. The poly (ethylene terephthalate) (PET) membranes were fabricated by electrospinning, and then grafted with acrylamide (AM) on the surface. The morphologies of the nanofiber was characterized by SEM, meanwhile, the chemical composition and element analysis on the membrane surface were measured by FT-IR and XPS, respectively. The Cu (II) adsorption experiment investigated the adsorption performance related to the pH value on. Equilibrium studies show that the adsorption process follows Langmuir model and the maximum adsorption capacity was estimated to be 183.25 [mg/g].
Authors: Dian Mo Zheng, Sheng Gan Zhu, Li Ping Wu
Abstract: Activated starch was prepared by ball milling before used. Graft copolymerization of acrylamide onto activated starch was carried out in inverse emulsion using a redox initiation system of ammonium persulfate and sodium bisulfite. The effects of ball-milling time, reaction temperature, initiator concentration and weight ratio of acrylamide to starch on the conversion of monomer, grafting percentage and grafting efficiency were studied. The structure and properties of the graft copolymer and activated starch were characterized by FT-IR, XRD and SEM. The results showed that ball milling could progressively destroy the crystalline structure of starch and improve the chemical reactivity. The monomer conversion, grafting percentage and grafting efficiency of grate copolymerization were 96.6%、62.4%、85.49%, respectively.
Authors: Ya Feng Cao, Zao Li Liu, Yuan Li, Feng Zhi Tan
Abstract: In aqueous two-phase system, azodiisobutyronitrile(AIBN) was adsorbed on starch by dissolve- precipitate method. Free radical was then produced by its thermolysis, thus graft copolymerization of starch and acrylamide could be initiated. The effect of factors such as initiating system, organic solvent for AIBN dissolving, time for pre-initiation, concentration of initiator, composition and concentration of disperse system on monomer conversion, grafting efficiency, and dissolution property of the reaction product were studied. The optimum conditions of the reaction were as follows: AIBN was used as initiator and methanol as solvent; pre-initiation time was 25 min; concentration of AIBN was 2.6×10-4 mol/L; polyethylene glycol (PEG) and polyvinyl alcohol (PVA) was used as disperse system, the ratio of m(PEG):m(PVA) was 2.0:1 and their total mass fraction was 6.5%; both pre-initiation and polymerization temperatures were 60-65 °C. Monomer conversion (C) and grafting efficiency (GE) of the product obtained under these conditions were 99.4% and 99.1%, respectively.
Authors: Zi Yi Wan, Ting Fei Xi, P. Zhao, Cheng Xiang Fan, Y. Sun, Z.G. Feng
Abstract: Polyacrylamide (PAM) was usually atoxic, stable. Its hydrogel (PAMG) has been used in plastic and aesthetic surgery more than 10 years in P.R.China, Ukraine and Russia. But there were some complications with PAMG injected in patients. Considering the complicacy in vivo, it was necessary to study the PAMG’s stability. In this paper, H2O2 was added in PAMG in vitro and acrylamide (AM) content after oxidating was determined using HPLC method. Detection limit for AM can be achieved in the parts-per-billion rang. The AM content in supernatant at 0.5, 1,2 and 3 hr after oxidating of PAMG was 1.27e-8g/ml, 1.35e-8g/ml, 1.03e-7g/ml and 2.74e-7g/ml, respectively. The AM content in supernatant of PAMG was 7.70e-9g/ml. These results indicated that PAMG can be degraded to AM by hydroxyl radical. Under the same condition, the AM content was stable. So, AM can exist for a while when it was produce by degrading of PAMG. That can increase the toxicity of PAMG.
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