Papers by Keyword: Acrylamide

Abstract: A technique for starch modification by graft polymerization of acrylamide has been developed. The obtained copolymer is soluble in a wide range of pH 2 - 12. The modification of starch made it possible to freely combine it with aqueous acid solutions of chitosan, in order to achieve a synergistic effect of their properties. A porous material based on modified starch and its mixtures with chitosan, which has high sorption characteristics, has been developed. The resulting material is promising as a sorbent of heavy metal ions and packing materials for transportation and storage.

Abstract: pH-sensitive hydrogels based on chitosan-graft-poly(acrylamide-co-sodium acrylate) were synthesized via radical polymerization in solution. Ammonium persulfate was used as initiator, and various amounts of hexamine were used as a cross-linking agent. The structure of obtained hydrogels was characterized by Fourier transform infrared spectroscopy. Moisture-absorbing power of hydrogels in buffer solution with various pH value (pH = 1.65; 4.01; 12.43) was investigated. It is turned out that such a copolymers have a high moisture retention capacity (swelling index attains the value 1100%) and are capable for reusing, that makes it possible to apply the hydrogels in different areas.

Abstract: In order to explore a smart carrier which can control drug delivery in special pH environment, a type of nanometer material, namely, poly acrylic acid acrylamide (P(AA-AM)) was synthesized with acrylic acid and acrylamide as monomers. Its structure was determined using Fourier transform infrared spectroscopy (FTIR) and its swelling properties were tested by measuring its weight evolution. The drug delivery control potential was estimated by monitoring its swelling performances in the solutions of different pH values. The cycle characteristics were also investigated to determine its degradation properties in the environment. The results indicate that the synthesized material is sensitive to pH and is suitable for controlling drug delivery at the pH range from 10 to11 and below 7. Furthermore, this material can be automatic decomposition in the environment so that it is a degradable green material without causing burden to the environment.

Abstract: PET material has excellent performance and its modification of biocompatibility had been concerned for researchers. In this paper, graft polymerization of acrylamide on PET fiber by co-irradiation was investigated, and then treated in 5% available chlorine content of NaClO solution, which make the amide groups on the PET fiber surface into amine groups, and provide the reactive groups for further functional modification. The results showed that the moisture absorption of PET fiber increases after the grafting of acrylamide, and its hygroscopicity increases with the increase of grafting yields; after the amide groups converted into the amine groups, the hygroscopicity of PET fibers decreases. The chemical structure and surface morphology of PET fiber and modified products were characterized by ATR-FTIR and SEM, which certified that acrylamide had been successfully grafted on PET fibers and the amide groups on its surface had been converted into the amine groups.

Abstract: A nanoSiO2/polyacrylamide (PAM) organic–inorganic nanocomposite system was prepared using acrylamide as the monomer, nanoSiO2 as the modifier, and ammonium persulfate as the initiator. The system was then used to investigate the impact of various factors, including amount of modifier and concentration of monomer, thereby determining the conditions for optimal reaction. Infrared spectroscopy was then used for structural characterization. Measurements using the viscosity method indicated that the viscosity average molecular weight of the product exceeded 1 million. Electron microscopy images showed that a good organic coating layer formed on the surface of the microspheres.

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.

Abstract: Electron beam irradiation grafting of acryl acid (AAc)/acrylamide (AAm) onto poly-(ethylene terephthalate) (PET) fabrics was performed using a high-energy electron accelerator. Parameters affecting the graft polymerization of PET fabrics, including composite of mixture monomer, monomer concentration radiation dose and, concentration of inhibitor were investigated. The thermal behavior of the grafted PET fabrics was investigated with thermogravimetric analysis. Findings showed that grafting with AAc/AAm could improve the thermal stability of PET.

Abstract: Adsorbent composites comprising of bentonite/sodium lignosulfonate graft-polymerized with acrylamide (BLPAM) were synthesized. Results showed that the optimized preparation conditions within the experimental range were as follows: the mass ratio of acrylamide to sodium lignosulfonate was 14, the pH of the reaction medium was 4.0, the mass concentrations of the initiator and cross-linker were 0.45% and 0.30%, respectively. The Pb²⁺ adsorption capacity of the as-prepared BLPAM was 0.161mmol/g.

Abstract: Adsorbent composites comprising of inorganic clay/sodium lignosulfonate graft-polymerized with acrylamide and maleic anhydride were synthesized by free radical solution copolymerization. The synthesized copolymers presented high adsorption capacity when the monomer ratio of acrylamide to maleic anhydride was 3:2 and montmrillonite was introduced as inorganic clay. The equilibrium adsorption of Pb²⁺ on these copolymers was well represented by Langmuir model which indicated that the Pb²⁺ adsorption was a monolayer chemical adsorption. The calculated adsorption capacity of the copolymers could reach a maximum of 176.70 mg/g for Pb²⁺ and 24.95 mg/g for Cu²⁺. In addition, these copolymers could selectively remove Pb²⁺ from Pb²⁺/Cu²⁺ binary solution and the maximum selective coefficient of Pb²⁺ to Cu²⁺ was 11.939.

Abstract: The micro-sized p(styrene-1,4-divinylbenzene)/polyacrylamide(p(St-DVB)/pAM) particles were prepared by a two-step method. P(St-DVB) cores were firstly obtained via concentrated emulsion polymerization, and then the cores were swelled sufficiently and reacted with acrylamide until p(St-DVB)/pAM particles were obtain. The morphologies and compositions of p(St-DVB)/pAM particles were characterized by scanning electron microscopy(SEM) and infrared spectroscopy(IR) individually. It was proved that the micro-morphologies of p(St-DVB)/pAM particles were nearly spherical or even peanut shape. It was also found that the diameter distribution of p(St-DVB)/pAM particles became narrower with the increasing of DVB amounts, and the same trade was also observed on emulsifier amounts.