Gelation behavior of polysaccharide-based interpenetrating polymer network (IPN) hydrogels

Area of Science:

• Polymer Science
• Materials Science
• Rheology

Background:

• Interpenetrating polymer networks (IPNs) are advanced polymer architectures.
• Limited research exists on the gelation behavior of alginate-HMEHEC IPNs.

Purpose of the Study:

• To prepare and rheologically characterize novel IPN hydrogels from alginate and hydrophobically modified ethyl hydroxyl ethyl cellulose (HMEHEC).
• To investigate the influence of polymer ratios and crosslinker density on IPN rheology and gelation properties.

Main Methods:

• Preparation of alginate-HMEHEC IPN hydrogels.
• Rheological characterization, including dynamic moduli measurements.
• Analysis of sol-gel transition using the Winter-Chambon criterion.

Main Results:

• IPN rheology is easily tunable, with elastic modulus dependent on HMEHEC/alginate ratio.
• Sol-gel transition satisfies the Winter-Chambon criterion across various crosslinker densities.
• Viscoelastic exponent (n) depends on crosslinker density and polymer ratio, averaging ~0.5 at stoichiometric crosslinking.

Conclusions:

• Alginate influences the kinetics of IPN formation.
• HMEHEC molecular weight impacts gel point and viscoelastic exponent, especially at lower concentrations.
• Tunable rheological properties make these IPNs promising for various applications.