Precipitation Polymerization Of Acrylamide Research Articles

Hydrophobically modified cationic oligoacrylamide as a potential shale hydration inhibitor in water-based drilling fluid and mechanism study

Inhibiting shale hydration is crucial for wellbore stability in oil and gas drilling operations when using water-based drilling fluids (WBDFs). In the study, a hydrophobically modified cationic oligoacrylamide (HCOA) was employed as a potential shale hydration inhibitor. It was prepared by precipitation polymerization of acrylamide (AAm), methylacrylethyl trimethylammonium chloride (DMC) and octadecyl acrylate (SA) in anhydrous ethanol. Characterizations were conducted by fourier transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance spectroscopy (1HNMR), fluorescence spectrophotometer (FR) and gel permeation chromatography (GPC). The results revealed the molecular weight of HCOA was 1.432 × 103 g/mol, and confirmed the hydrophobic association behavior in aqueous solution. The performance of HCOA on inhibiting shale hydration was evaluated by shale cuttings hot-rolling dispersion test, relative inhibition ratio and linear swelling measurements. The results showed that HCOA can perform as an effective shale hydration inhibitor. The rheological and filtration tests of WBDF demonstrated that HCOA can considerably decrease the high temperature high pressure filtration loss (FLHTHP) of WBDF and had no negative effect on the WBDF's rheological property. The inhibition mechanism study revealed that HCOA could adsorb on the clay surface via electrostatic binding and form a hydrophobic layer to prevent contact between water molecules and clay particles, rather than intercalating into clay interlayers to inhibit shale hydration. This study might provide a basis for the design of permanent shale inhibitors for drilling fluids.

Design and preparation of flocculant with self-degrading characteristics for dewatering of oil sand tailings

Polymer flocculation technology is widely used in the treatment of oil sand tailings pollutants. However, the most commonly used polyacrylamide flocculants have problems of secondary pollution. In this paper, under ultraviolet light, the composite was prepared by photoinitiated precipitation polymerization of acrylamide on the surface of nano TiO2, providing a facile strategy for the synthesis of organic-inorganic hybrid flocculants. A series of organic-inorganic hybrid materials with different light sources, UV irradiation times, TiO2 contents and AM contents were synthesized, and connected by covalent bonds. In addition, in order to analyze the synthesis mechanism of the composite material, the functional groups of the material were investigated by Fourier transform infrared spectroscopy (FTIR), the morphology and structure were observed by transmission electron microscopy (TEM), and thermodynamic stability was analyzed by thermogravimetry. The flocculation mechanism was studied by testing the zeta potential and GPC spectrum of the organic-inorganic composites. Moreover, the composite material increased the transmittance by 74.33% and decreased the water volume by 84% for simulated oil sand tailings. Ultimately, the degradation experiments showed that the prepared organic-inorganic composite flocculant had nice self-degradation performance, which efficiency could reach over 90% within 2 hours. In conclusion, this material can be employed to enhance the recovery of water from oil sand tailings, also with outstanding degradation characteristics.

Study on the Precipitation Polymerization of Acrylamide and Methacrylic Acid in Ethanol by Conductimetry: Phase- Separation Prior to Polymerization

Conductimetry was employed to investigate the precipitation polymerization of acrylamide/methacrylic acid (AAm/MAA) in ethanol (EtOH). The conductivity change vs. temperature of AAm/MAA-EtOH as well as the effects of monomer ratio and monomer concentration was studied. An abrupt decrease of conductivity in AAm/MAA-EtOH was observed at ca 25°C, indicating the phase separation of monomers and EtOH. As the ratios of AAm/MAA increased from 2/1 to 5/1 (wt/wt), the phase separation temperature increased from 22 to 31°C. The higher the monomers concentration, the temperature of phase separation is lower. These results proved that the lyophobicity of methyl group of MAA dominated the phase separation and the precipitation polymerization system of AAm/MAA-EtOH, by which the microspheres were prepared, was heterogeneous prior to the polymerization.

Study on the Precipitation Polymerization of Acrylamide and Methacrylic Acid in Ethanol by Conductimetry: Phase- Separation Prior to Polymerization

Conductimetry was employed to investigate the precipitation polymerization of acrylamide/methacrylic acid (AAm/MAA) in ethanol (EtOH). The conductivity change vs. temperature of AAm/MAA-EtOH as well as the effects of monomer ratio and monomer concentration was studied. An abrupt decrease of conductivity in AAm/MAA-EtOH was observed at ca 25°C, indicating the phase separation of monomers and EtOH. As the ratios of AAm/MAA increased from 2/1 to 5/1 (wt/wt), the phase separation temperature increased from 22 to 31°C. The higher the monomers concentration, the temperature of phase separation is lower. These results proved that the lyophobicity of methyl group of MAA dominated the phase separation and the precipitation polymerization system of AAm/MAA-EtOH, by which the microspheres were prepared, was heterogeneous prior to the polymerization.

Precipitation polymerization of acrylamide with quaternary ammonium cationic monomer in potassium carbonate solution initiated by plasma

AbstractPrecipitation polymerization of 2‐(methacryloyloxyethyl) trimethyl ammonium chloride (DMC)‐co‐acrylamide (AM) [poly(AM‐DMC)] has been successfully performed in potassium carbonate (K2CO3)‐water media by plasma initiation. K2CO3 solution was selected because not only the higher solubility of AM and DMC comparing with that of poly(AM‐DMC), but the higher intrinsic viscosity of poly(AM‐DMC) could be obtained. A set of experiments was performed using different K2CO3 concentration (from 50 down to 10% (w/w)), thus the precipitation architecture was not obtained below 20% (w/w). And particles size, particles size distribution (7–120 μm), and intrinsic viscosity of poly(AM‐DMC) (ranging up to 455 cm3/g) were also summarized in this article. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 4060–4067, 2007

Preparation and Characterization of Monodisperse Polyacrylamide Microgels

Monodisperse microgels were prepared by the precipitation polymerization of acrylamide with acryloyl-terminated-poly(ethylene glycol) (PEG) macromonomer as a stabilizer. The process was carried in ethanol, methanol, and a mixture of two. The size of microgels was controlled to the range of 0.06—1.0 μm, changing the solvent. GPC profiles and particle size distribution of the microgels were narrow and monodisperse. Microgels were dispersable in water, and showed very low viscosity, and were stable in polar solvents and KCl aqueous solution.

Phagocytosis of microspheres with modified surfaces

A series of hydrogel microspheres having different polystyrene (PSt) contents was prepared by the precipitation polymerization of acrylamide (AAm) and comonomers followed by the seeded polymerization of styrene (St). The resulting AAm-St microspheres had different morphologies and surface properties dependent on the amount of St charged in the seeded polymerization. These AAm-St microspheres were contacted with granulocytes in phosphatebuffered saline (PBS) or plasma at 37 °C to clarify the effect of surface structure of the microspheres and of blood components on phagocytosis. Phagocytosis of the microspheres by granulocytes in PBS was enhanced with increasing PSt content in the microspheres. This suggested that the hydrophobicity of the microspheres is one of the major factors deciding the extent of phagocytosis in PBS. On the other hand, the extent of phagocytosis in plasma depended on the PSt content in the microspheres in an unexpected manner. The microspheres with a small content of PSt were less susceptible to phagocytosis than the microspheres containing no St. Phagocytosis in inactivated serum was slight, regardless of the type of microspheres. These results suggested that complement and the complement-immunogloblin G complex are responsible for the enhancement of phagocytosis of hydrophilic and hydrophobic microspheres, respectively.

Preparation of Core-Corona Type Microgels of Polyacrylamide

Precipitation polymerization of acrylamide (AAm) and acryloyl terminated PEG macromonomer (AtPEGM) was carried out in selective solvents such as alcohol. Fine particles of microgels were obtained according to the mole ratio of AtPEGM and AAm. The particle size of microgels decreased with increasing concentration of AtPEGM and increased with that of AAm. It was found that microgels were stabilized by steric stabilization of AtPEGM and have the morphology of core-corona type with the size distribution of submicron.

Preparation and modification of monodisperse hydrogel microspheres

AbstractMonodisperse hydrogel microspheres were prepared by precipitation polymerization of acrylamide and comonomers in ethanol and propan‐2‐ol and their mixtures. The size of the microspheres varied from 0.2 to 1.3 μm as a function of the solubility parameter of the dispersants. The applicability of the three‐component solubility parameter approach by Paine was examined. Seeded polymerization of styrene using the seed microspheres mentioned above yielded unique composite microspheres whose surface property changed gradually with the content of styrene.

Hydrogel Microspheres II. Precipitation Copolymerization of Acrylamide with Comonomers to Prepare Monodisperse Hydrogel Microspheres

Precipitation polymerization of acrylamide (AAm) and methylene-bisacrylamide (MB) was carried out in alcohols. Large, bulky and porous particles were formed by the polymerization. On the contrary, copolymerization of AAm and MB with a certain amount of methacrylic acid (MAc) resulted in the formation of fine monodisperse hydrogel microspheres. This was attributed to the contribution of MAc units to the stabilization of the particles formed at the initial stage of polymerization and the enhancement of swelling of the particles by monomer and alcohol.

Precipitation polymerization of acrylamide using vazo‐33 as an initiator and acetonitrile/water mixtures as the solvent

AbstractPrecipitation polymerization of acrylamide initiated by a thermal initiator, Vazo‐33 (DuPont Vazo Initiator), was achieved at a solvent composition of acetonitrile/water = 4/6 (vol/vol). The polymerization kinetics were investigated in the acrylamide [M] concentration range 0.86–2.27M, Vazo‐33 [I] concentration range 1.4–11.0 × 10−4M, and temperature range 30–40°C. Polymerization was carried out in reaction ampules and the rate was determined gravimetrically. Number‐average molecular weight was obtained from intrinsic viscosity. The precipitation polymerization rate varied as [M]2.16 and [I]0.44. Number‐average molecular weight was proportional to [M]1.22 and inversely proportional to [I]0.31. The overall reaction activation energy was calculated as 17.3 kcal/mol in the temperature range studied. The optimal reaction conditions studied were: acetonitrile/water = 4/6, temperature = 40°C, [M] = 1.95M and [I] = 2.8 × 10−4M. One hundred percent conversion was achieved in 90 min and a polymer with a number‐average molecular weight of 1,200,000 was obtained.