Effect of AMPS(2-acrylamido-2-methylpropane sulfonic acid) content on the properties of polymer gels

The BST oilfield in the northwestern Taklamakan Desert is a fractured carbonate reservoir,but issues of water breakthrough are becoming increasingly severe with the development of water flooding.Unfortunately,the high-temperature and high-salt conditions(130°C,71695 mg/L)of the BST oilfield pose challenges for the development of plugging agents.In this study,the effects of 2-acrylamido-2-methylpropane sulfonic acid(AMPS)content on AM/AMPS copolymers and gels were studied through viscosity measurements,nuclear magnetic resonance(NMR),and cryo-scanning electron microscope(Cryo-SEM).Moreover,the AMPS stabilization mechanism of the polymers and gels was explained.Heatresistant and salt-tolerant gel systems were developed,and their gelation properties,thermal stability,injection capacity,and plugging ability were evaluated.Experimental results showed inconsistencies between the effects of AMPS content on the polymers and gels.For the polymers,the thermal stability increased with increased AMPS content in the polymer.However,excessive AMPS content resulted in poor gelation and low strength.The developed gel systems with S30 polymer(AMPS content is approximately 26%)exhibited excellent thermal stability,controllable gelation time,good injection capacity,and plugging ability.The field application results indicated that most production wells had a positive response,with reduced water-cut and increased daily oil production.

Synthesis and Characterization of the Terpolymer of Itaconic Acid with Acrylamide and 2-Acrylamido-2-methylpropanesulfonic Acid

The terpolymer of itaconic acid, acrylamide and 2-acrylamido-2-methyl-1-propane sulfonic acid was synthesized through the free-radical polymerization. The IR spectra confirmed that there was no olefinic band, while the TGA results revealed that the terpolymer was of high thermal stability.

Chemical Modification of Scraped Tires through Grafting with 2-Acrylamido-2-methylpropansulfonic Acid

Scrap vulcanized rubber is amongst a bigger waste polymers. It does not decompose easily owing to its cross linked structure. Modification of scrap tires powder by the grafting with 2-acrylamido-2-methylpropanesulfonic acid (AMPS) is described. The grafting is achieved through free radical initiation. The effects of different amount of monomer and initiator were examined. Also the influence of reaction time and temperature were investigated. The grafted waste rubber was characterized by FT/IR, SEM and DSC measurements. The proposed mechanism of the grafting reaction is discussed. From DSC and SEM studies of WR-g-AMPS compared with PAMPS and WR, the results show that the particle size and crystallinity were enhanced for the grafted copolymers. The obtained modified scraped tires will used as an ion exchanger for the future applications.

COPOLYMERS OF 2-ACRYLAMIDO-2-METHYL-1-PROPANESULFONIC ACID/MALEIC ACID:SYNTHESIS,CHARACTERIZATION AND ANTIMICROBIAL ACTIVITY

2-Acrylamido-2-methyl-1-propanesulfonic acid （AMPS）, and maleic acid （MA） copolymerized with different feed ratios using N,N-dimethylformamide as a solvent and benzoyl peroxide （Bz2O2） as an initiator at 70℃. Structure and composition of copolymers for a wide range of monomer feed were determined by elemental analysis （content of N for AMPS-units）. Monomer reactivity ratios for AMPS （M1）-MA （M2） pair were determined by the application of conventional linearization methods such as Fineman-Ross （F-R）, Kelen-Tudos（KT） and Extended Kelen-Tudos （EKT） and a nonlinear error invariable model method using a computer program RREVM. The characterizations were done by Fourier transform infrared spectroscopy （FTIR）, differential scanning calorimetry （DSC） thermal gravimetry analysis （TGA）, and and X-ray diffraction. The antimicrobial effects of polymers were also tested on various bacteria, and yeast.

Preparation of organically functionalized silica gel as adsorbent for copper ion adsorption

A novel adsorbent （AMPS-silica） was synthesized by bounding AMPS （2-acrylamido-2-methylpropanesulfonic acid） onto silica surface, which functioned with γ-methacryloxypropyltrimethoxysilane reagent. The adsorbent was characterized by nitrogen adsorption/desorption measurement, thermogravimetric analysis （TGA） and potentiometric titration analysis. The TGA result indicated that the surface modification reactions introduced some organic functional groups onto the surface of silica. The surface area of AMPSsilica was 389.7 m2/g. The adsorbent was examined for copper ion removal in series of batch adsorption experiments. Results showed that the adsorption of Cu2＋ onto AMPS-silica was pH dependent, and the adsorption capacity increased with increasing pH from 2 to 6. The adsorption kinetics showed that Cu^2＋ adsorption was fast and the data fitted well with a pseudo secondorder kinetic model. The adsorption of Cu^2＋ onto AMPS-silica obeyed both Freundlich and Langmuir isotherms, with r^2 = 0.993 and r^2 = 0.984, respectively. The maximum Cu^2＋ adsorption capacity was 19.9 mg/g. The involved mechanism might be the adsorption through metal binding with organic functional groups such as carboxyl, amino and sulfonic groups. Cu^2＋ loaded on AMPS-silica could be desorbed in HNO3 solution, and the adsorption properties remain stable after three adsorption-desorption cycles.

Waterborne Epoxy Resin Modified by AMPS

A stable epoxy emulsion was prepared with epoxy resin （EP） as raw material, 2-acrylamido-2- methyl-l-propanesulfonic acid （AMPS） as modifier and benzoyl peroxide as initiator. By criterion of yield of the copolymer AMPS-EP, water-solubility, change of the acid value and intrinsic viscosity [η] along with reaction time, the copolymerization course was deduced. It is found that during the process, AMPS takes part in both the grafting copolymerization with epoxy principal chain and the ring-opening polyaddition with epoxy group. It is also discovered that the yield of AMPS-EP and water dispersing varies with reaction time. When it reaches 1.5 h, AMPS-EP can obtain good water-solubility; but the water-solubility will go bad gradually if it exceeds 3.5 h.. R spectrum analysis indicates that partial epoxy group partially remains and the others create sulfonic ester.

Investigation of Swelling/Sorption Characteristics of Highly Swollen AAm/AMPS Hydrogels and Semi IPNs with PEG as Biopotential Sorbent

The aim of this study was to investigate the equilibrium swelling and sorption properties of chemically crosslinked copolymeric hydrogels as biopotential sorbent consisting of acrylamide (AAm) and 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS). Semi-interpenetrating polymer network (semi IPNs) hydrogel, composed of AAm with AMPS as co-monomer, with poly (ethylene glycol) (PEG) and a multifunctional crosslinker such as trimethylolpropane triacrylate (TMPTA) was prepared. AAm/AMPS hydrogels and AAm/AMPS/PEG semi IPNs were synthesized by free radical solution polymerization by using ammonium persulphate (APS)/N,N,N’,N’-tetramethylethylenediamine (TEMED) as redox initiating pair. Swelling experiments were performed in water, 0.01 M and 0.03 M aqueous urea solutions at 25oC, gravimetrically. The hydrogels showed enormous swelling in aqueous urea/water medium and displayed swelling characteristics that were highly depended on the chemical composition of the hydrogels. FTIR spectroscopy was used to identify the presence of different repeating units in the semi IPNs. Some swelling and diffusion characteristics were calculated for different semi IPNs and hydrogels prepared under various formulations. For sorption of cationic dye, Lauths violet into the hydrogels was studied by batch sorption technique at 25oC. Dye removal capacity, adsorption percentage and partition coefficient of the hydrogels was investigated. Swelling and dye sorption properties of AAm/AMPS hydrogels and AAm/AMPS/PEG semi IPNs were investigated as a function of chemical composition of the hydrogels.

CONDUCTIVITY AND DIELECTRIC BEHAVIOR OF PLiAMPS-BASED SEMI-IPN SINGLE ION CONDUCTOR PLASTICIZED WITH POLY(SILOXANE-G-ETHYLENE OXIDE)

Comb poly(siloxane-g-ethylene oxide)(PSi-PE)with high chain segmental mobility,as a plasticizer,was introduced into poly(lithium 2-acrylamido-2-methyl-1-propanesulfonate)(PLiAMPS)-based semi-interpenetrating polymer network single-ion conductors.The structures of PSi-PE and PLiAMPS were characterized by FTIR spectroscopy.The distribution of PSi-PE in polyelectrolyte matrix was investigated through observing the residual surface morphology of conductor membrane after being etched by toluene.AC impedance and dielectric behavior measurements were used to investigate the impact of PSi-PE on the ionic conductivity and to analyze the mechanism of conductivity variation.Compared with the unplasticized membranes,the ionic conductivity of the membrane with the addition of 35 wt.%PSi-PE was improved by 20 times.Meanwhile,the dielectric constant(ε)of the membrane was increased to 1330 and the relaxation time was decreased to 0.012 s.The changes of dielectric properties reflect directly the effect of PSi-PE on the dissociation ability of Liþand the chain segmental mobility,which well explains the reasons of ionic conductivity variation.