Synthesis and rheological properties of hydrophobically modified polyacrylamides with lateral chains of poly(propylene oxide) oligomers

Insight into the Interaction Between Carbopol® 940 and Ionic/Nonionic Surfactant

“…The critical aggregation concentration (CAC) represents the minimum concentration of a surfactant required for the beginning of the interaction with polymer. At the polymer saturation point (PSP) polymer chains are saturated with surfactant [29,31]. In order to determine CAC and PSP values at different polymer concentrations, the following Carbopol Ò polymer concentrations were titrated with SDS: 0.01, 0.02, 0.03, 0.04, 0.05 and 0.06 % (w/v).…”

A novel thermoviscosifying water‐soluble polymer: Synthesis and aqueous solution properties

“…In the semidilute regime, hydrophobic clusters involving LCST grafts covalently linked to different water-soluble backbones should induce above T ass the formation of physical crosslinks between the mainchains, giving rise to a viscosity enhancement macroscopically. Basically, two types of thermosensitive functionalities were introduced onto polymer backbones with grafting technique: one was polyethylene (PEO) or copolymer of PEO and poly(propylene oxide) (PPO) that was grafted via a coupling reaction onto the mainchains of a low-molecular weight hydrosoluble parent polymer, for example, poly(acrylic acid) (PAA), 34,36 PAM, 37 copolymer of AA and 2-acrylamido-2-methyl propanefulfonic acid (AMPS), 38 terpolymer of AM, AMPS, and N-ethyl vinyl acrylamide, 37 even the natural polysaccharide such as carboxymethylcellulose, aliginate, and carboxylated dextran 39 ; or copolymerization of acrylamide with PPO-based macromonomers 40,41 ; another was N-isopropylacrylamide (NIPAM)-based amino-end functionalized macromonomer, 42 or the oligomer of NIPAM and other comonomers such as AM, AMPS, or butyl methacrylate, 43 which was grafted onto low-molecular-weight PAA backbone through a twostep process. Grafting method used in above functionalizations can control the primary structure of the copolymers and particularly the length and the molecular weight distribution of the backbone, as well as the placement of grafts along the main chain.…”

Synthesis and solution behavior of hydrophobically associating polyacrylamide containing capsaicin‐like moieties

“…29 The solubilization of hydrophobic comonomers in micelles causes an increase in their apparent reactivity due to the local concentration effect of the micelles, and consequently, the hydrophobic comonomers are consumed more rapidly than other comonomers. 2 Thus, samples obtained at high conversion, e.g., PAAHO-0.60 and PAAHO-0.65, may contain an important proportion of polymer chains that possess no hydrophobe units, and then this heterogeneity will impede the formation of intermolecular associations and alter the rheological behavior. 30 The result agrees with the already reported results on HAPAM that the polymer sample with increased homogeneity shows strongly enhanced thickening properties, while the heterogeneous polymer does not exhibit significant associative properties.…”

“…1 However, these polymers could exhibit a loss of their viscosifying properties when subjected to strong mechanical deformations, increasing ionic strengths, or high temperature. 2,3 To overcome these drawbacks, hydrophobically modified water-soluble polymers have been widely studied in both academic and industrial laboratories. In particular, hydrophobically associating polyacrylamides (HAPAMs) that contain a relatively small amount of hydrophobic groups attached along the acrylamide (AM) backbones have received increasing attention on account of their unique rheological characteristics.…”

“…12,13 Recently, various types of processes have been used to improve the temperature-tolerance property of HAPAMs, such as incorporating more thermal stable or rigid monomers into the copolymer backbone to minimize excessive hydrolysis, 6,14 or inserting lateral chains which present a loss of water solubility above a critical temperature, giving rise to a viscosity enhancement. 2,3 N-(4-hydroxy-3-methoxy-benzyl) acrylamide (HMBA), a unique functionalized AM monomer derived from capsaicin, was designed and synthesized in our laboratory. A detailed description of the synthesis of HMBA has been previously reported.…”