Synthesis, characterization and rheological properties of acrylamide/ acidic monomer/ N-(4-ethylphenyl) acrylamide Terpolymers as pH- responsive hydrogels and nanogels

ABSTRACT

Novel pH-responsive superabsorbent hydrogels (HGs) and nanogels (NGs) with high water uptake and adjustable viscoelastic behavior were synthesized by free radical polymerization of acrylamide (AM) and a small amount of N-(4-ethylphenyl)acrylamide (EΦAM) hydrophobic comonomer in the presence of three different acidic monomers. Structure of the synthesized linear terpolymers was investigated by ¹H-NMR spectroscopy. The solution viscosity of the linear terpolymers was measured at different pH and temperatures, where AM-EΦAM-AMPS terpolymer showed higher viscosity in different conditions. Equilibrium swelling ratio (ESR) of hydrogels was studied using response surface methodology and empirically modeled as a function of pH and temperature as stimuli.

Graphical Abstarct

KEYWORDS:

• Hydrophobically modified hydrogels and nanogels
• stimuli responsive smart materials
• acidic comonomer
• superabsorbent hydrogels and nanogels
• synthesis and characterization
• rheology

Conflict of interest

The authors declare that they have no conflict of interest.

Additional information

Funding

The authors would like to acknowledge the Tarbiat Modares University [9491] for the financial support.

Notes on contributors

Hossein Khakpour

Hossein Khakpour received his BSc in Chemical Engineering from Isfahan University of Technology in 2012. He then completed an MSc in Polymerization Processes Engineering at Tarbiat Modares University in 2015 with a focus on chemistry of hydrphobically modified polymers and their rheological responses. Hossein’s research focuses on synthesis and characterization of functionally-modified polymers, nanoparticles and soft materials and rheological behavior of complex fluids such as polymer solutions, colloidal and non-colloidal suspensions.

Mahdi Abdollahi

Mahdi Abdollahi is currently an associate professor of polymer reaction engineering at Tarbiat Modares University, Faculty of Chemical Engineering. He joint the Faculty of Chemical Engineering in 2011. He earned his B.Sc. in applied chemistry in 2001 from Tabriz University, M.Sc. in polymer science and technology in 2003 from Iran Polymer and Petrochemical Institute (IPPI) and Ph.D. in polymer engineering in 2009 from Tarbiat Modares University (TMU). His main research interests include 1) Design, Synthesis and Characterization of Polymers, 2) Modification of Natural Polymers as Environmentally Friendly Materials and Their Application Development, 3) Kinetics and Applications of Emulsion Polymerization, 4) Polymeric Membranes (Microstrucure- Property Relationship), 5) Kinetic Modeling of (Controlled) Radical Polymerization and 6) Polymers in Corresponding industries.