Preparation of porous polyacrylamide hydrogels by frontal polymerization

Abstract

Polyacrylamide hydrogels with defined porous structure were synthesized through frontal polymerization (FP) in the presence of NaHCO3 as a foaming agent. Pore properties were analyzed using scanning electron microscopy and mercury intrusion porosimetry. The as‐prepared hydrogels displayed a small cell diameter of ca 2 µm. The dissolved foaming agent dispersing at the level of molecules and the polymerization front propagating step by step should be responsible for the small uniform cell structure. The pore volume varied from 0.63 to 3.65 cm3 g−1 and the bulk density changed from 0.48 to 0.28 g cm−3 for a foaming agent content from 0 to 18%. The hydrogels synthesized by FP exhibited higher swelling rate and swelling ratio with respect to conventional batch polymerization. The highest swelling ratio and rate were obtained at a foaming agent concentration of 12% based on monomer. Copyright © 2007 Society of Chemical Industry

Frontal Polymerization

“…The first direction is to use it to make new types of polymers or existing polymers more easily. For example, FP has been used for the preparation of amphilic gels [69], polymers for controlled release [70], and porous polyacrylamide hydrogels [71].…”

Preparation and performance of thermosensitive poly(N‐isopropylacrylamide) hydrogels by frontal photopolymerization

“…Washington and Steinbock first demonstrated that FP enables the preparation of homogeneous poly( N ‐isopropylacrylamide) (PNIPAm) hydrogels without compromising their temperature‐dependent property. Ge and colleagues investigated the mechanism of hydrogel preparation by FP in detail and successfully synthesized various hydrogels, such as poly(acrylic acid), polyacrylamide, PNIPAm and so on. Chen and colleagues prepared thermosensitive and pH‐sensitive hydrogels with excellent swelling properties by using such new facile strategy.…”

Synthesis of porous poly(acrylamide) hydrogels using calcium carbonate and its application for slow release of potassium nitrate

“…The application of PAAm hydrogels in controlled release of agrochemicals and bioactive have been investigated [16,17]. Researchers have been reported porous PAAm hydrogels [18][19][20]. Synthesizing porous hydrogels using solution polymerization method in the presence of porogen (that produce gas bubbles from reaction of porogen with chemicals) is a difficult task, because produced gas bubbles from porogen leave the solution easily.…”