High‐molecular‐weight hydrolyzed polyacrylamides. II
Potentiometric titrations in water of high‐molecular‐weight partly hydrolyzed polyacrylamides were analyzed by the Lifson—Katchalsky rodlike model. A fair concordance was found between theory and experimental curves with pK0 of acid functions of about 4.75 when 0 < τ < 0.49. Two methods were derived to calculate the parameter n of the extended Henderson‐Hasselbach equation by using a
High-molecular-weight partially hydrolyzed polyacrylamides are widely used in enhanced oil recovery. Mechanical degradation of these polymers as a result of flow through pumps, chokes, valves and at the sand face has been recently reported to have a negative impact on the application.
High molecular weight hydrolyzed polyacrylamides. III
The effect of temperature (100°C) and heating time (up to 384 hr) on the physicochemical properties of high molecular weight ( M̄p ≅ 4 × 10 6) partly hydrolyzed (τ ≅ 31%) polyacrylamide (HPAM‐25) solutions with initial pH values near 4 and 7, respectively, is reported. Potentiometric and spectroscopy data indicate that upon heating the solutions for 16 days the extent of hydrolysis is increased up to around 90%.
The effect of ionization (α) and added salts (NaCl, CaCl2, MgCl2) on the dimensions of commercially available high‐molecular‐weight polyacrylamides (Mw ≃ 4 × 106), hydrolyzed at various extents (0.04 < τ < 0.49) and which have been characterized, was investigated by viscosity and light‐scattering measurements performed at 25°C.
US4617359A - High molecular weight polyacrylamide
The molecular weight maximum is generally reached at a molecular weight jumper level in the reaction media of 8 to 12 phm (parts per 100 parts of monomer by weight). The preferred amount of molecular weight jumper for use in the aqueous reaction media of this invention ranges from 4 weight percent to 15 weight percent.
Nonionic polyacrylamides with broad MWD used . pecially those for high molecular weight samples, determined by viscometry for hydrolyzed PAM .
Rheology and mechanical degradation of high-molecular
High-molecular-weight hydrolyzed polyacrylamides are used to increase the viscosity of water for a better oil displacement in polymer enhanced oil recovery (Sorbie, 1991). Polymer chains in solution can be irreversibly degraded through chain scission and/or structure reformation by mechanical, chemical and biological mechanisms ( Sorbie, 1991 , Caulfield et al., 2002 ).
High-molecular-weight hydrolyzed polyacrylamides. I. Characterization. Effect of salts on the conformational properties
Muhammad Tahir, Rafael E. Hincapie, Michael Be, Leonhard
Two synthetic high molecular weight hydrolyzed polyacrylamides (HPAM) polymers and one bio-polymer are used in this work. Polymer solutions are prepared at three concentrations 500 ppm, 1000 ppm and 1500 ppm. The prep-aration procedure used is the one adopted by Hincapie and Ganzer, [20]. A de-
The viscosity of dilute and semi dilute solutions of high molecular weight hydrolyzed polyacrylamides in water-glycerol-sodium chloride mixtures have been measured as function of the shear stress with a Bohlin Constant Stress rheometer. Shear thinning behaviour is observed up to a critical value of the shear stress, depending on the concentration.
Prevention of network destruction of partially hydrolyzed
High temperature and a high salt content in oil reservoirs significantly decrease the performance of polymer flooding. In this work, the viscoelastic properties of a partially hydrolyzed polyacrylamide (HPAM) solution with and without salt (NaCl) and at two different temperatures (35 °C and 70 °C) were evaluated using rheological approaches.
The solution was composed by a partially hydrolyzed polyacrylamide (HPAM) copolymerized with acrylamide tert-butyl sulfonate (ATBS) in a brine of 10.5% TDS containing both mono and divalent ions. Oxygen was dissolved in the solution, and iron was available from the bottle internal wall surface, which resulted in chemical degradation.
- How does polyacrylamide affect the environment?
- By employing sustainable production practices, minimizing chemical usage, and optimizing application methods, the environmental footprint of polyacrylamide can be significantly reduced. The environmental impact of polyacrylamide serves as a reminder of the intricate balance between technological advancement and ecological responsibility.
- What is the global polyacrylamide market size?
- The global polyacrylamide market size was valued at USD 4.5 billion in 2018 and is projected to expand at a CAGR of 6.2% from 2019 to 2025 . In volume, this represents an output of about 2.5 million tons. Polyacrylamide, or PAM, is made from the acrylamide monomer.
- Can polyacrylamide reduce environmental footprint?
- R&D members of the SNF Group have published an article on how the polyacrylamide industry is reducing environmental footprint through utilizing bio-based raw materials and monomer manufacturing improvements, as well as the environmental fate of these polymers and how they reduce end-use energy consumption and carbon dioxide emissions.
- What is polyacrylamide (PAM)?
- Polyacrylamide (PAM) is a long chain, linear, water soluble polymeric substance formed from acrylamide (C 3 H 5 NO) subunits, has a high molecular weight of typically from few 1000 to 20 × 10 6 g/mol, and has a very high viscosity in aqueous solutions, depending on the concentration and the degree of polymerization (Sojka et al. 2007).
