How are hydrophobically modified polyacrylamides synthesized?

The hydrophobically modified polyacrylamides (HM-PAMs) were synthesized according to reaction in Scheme 1. Free radical polymerization of acrylamide only and copolymerization between acrylamide and each surfmer occurred at low temperature (40 °C) via redox initiation system (KPS and NaBiS).

What is water soluble hydrophobically modified polyacrylamide (hmpam)?

The water-soluble hydrophobically modified polyacrylamide (HMPAM) has been extensively investigated in the last thirty years. Research interest stems mainly from two areas: solutions and hydrogels. Interest in HMPAM solutions has arisen primarily from controlling viscosity at different shear rates (rheology) in many technologies.

Which redox initiators were used in the copolymerization of HM-Pam?

The copolymerization was initiated by redox initiators composed of potassium peroxodisulphate and sodium bisulfite. The emulsion was stabilized using mixed tween 85 and span 80 as nonionic emulsifiers. The prepared HM-PAMs were classified into three groups according to the surfmers used in the copolymerization.

What is a 1 H NMR spectra of polyacrylamide?

The 1 H NMR spectra of polyacrylamide (PAM), Poly (AM-co-OSA-eo22Ac) (PAM-Ia) and Poly (AM-co-O-OS-eo22Ac) (PAM-IIIa) are illustrated in Fig. 3 (a–c). The 1 H NMR spectrum (3a) shows chemical shifts between б (1) and (2.5) for 1 H protons (a) and (b) in –C H 2 and –C H of acrylamide units.

How can a polymerization reaction be overcome?

This problem can be overcome by carrying out the polymerization reaction in a mixture of solvents where both monomers are soluble , , , or by using a micellar polymerization technique in which the presence of a surfactant in the micellar state ensures solubilization of the hydrophobe in the aqueous medium , , .

What is hmpam polymer?

HMPAM consists of a water-soluble polymer containing a small number of hydrophobic groups.