Synthesis and characterization of hydroxyethyl methacrylate/acrylamide responsive hydrogels

Abstract

Hydrogels based on an aqueous solution of hydroxyethyl methacrylate (HEMA) and acrylamide (AM) in the presence of trithioglycolic acid (TTGA) were prepared under the effect of gamma irradiation. These hydrogels were characterized by IR spectroscopy and thermogravimetric analysis and investigated for temperature-and pH-responsive materials. It was found that TTGA is essential for the formation of HEMA/AM hydrogels at different compositions, in which the gel fraction depends on composition. A binary mixture of HEMA and AM at equal ratios was the critical composition that forms hydrogels, even in the presence of TTGA. The IR spectroscopic analysis showed that the formation of hydrogels depends on hydrogen bonding and crosslinking. The TGA investigations with respect to mass loss and the temperatures of the maximum value of the rate of reaction showed that HEMA/AM hydrogels possess higher thermal stability than that of pure HEMA and this stability increases with increasing ratio of the AM component. Also, it was observed that the temperature of the maximum value of the rate of thermal decomposition reaction depends on hydrogel composition. However, calculations of the activation energy showed that the hydrogel composed of 90% HEMA and 10% AM exhibits the highest thermal stability during the increasing or decreasing rate of reaction. Kinetic studies of swelling in water showed that HEMA/AM hydrogels displayed a temperature-responsive character within the temperature range 25-30°C, and showed a stepwise swelling behavior in the pH range 2-10, depending on composition.

Synthesis and characterization of hyperbranched poly(silyl ester)s

“…Samples of the prepared hyperbranched poly(silyl ester)s were accurately weighed ( W 0 ) and then extracted with distilled THF using a Soxhlet system for 12 h. After extraction, the samples were dried in a vacuum until a constant weight was reached ( W ) 23 The results show that polymers II–V were soluble completely in THF and no gelation occurred, which is in accordance with the literature that the hyperbranched polymers possess high solubility 9.…”

Uranyl Ion Sorption Characteristics of Novel Polymer/Montmorillonite/Carboxymethyl Cellulose‐Composite Biosorbent‐Based AAm/AMPS Hydrogels and Semi‐IPNs

“…Numerous of synthetic and naturally derived materials have been studied to form well‐characterized hydrogels. Natural polymers such as polysaccharides have been studied by many researchers . Due to their specific properties, they have been used in many fields of biotechnological applications.…”

“…Carboxymethyl cellulose (CMC) is an anionic carboxymethyl ether of cellulose with tasteless, nontoxic, and water‐soluble characteristics. It has some potential applications in industrial fields as a stabilizing agent, thickening agent, and bonding agent . CMC has a number of polar carboxyl groups, hence CMC is chemically reactive and has strong hydrophilic characteristics.…”

“…CMC has a number of polar carboxyl groups, hence CMC is chemically reactive and has strong hydrophilic characteristics. With these as properties, CMC can be easily modified through its polymerization with hydrophilic vinyl monomers to synthesize new hydrogel systems . Montmorillonite (MMT), kaolin, attapulgite, and mica sericite have all been used to fabricate new polymeric composites .…”

Influence of the ionic character of a drug on its release rate from hydrogels based on 2-hydroxyethylmethacrylate and acrylamide synthesized by photopolymerization

“…Photopolymerization has been employed to obtain hydrogels for drug delivery applications using a variety of mono functional monomers such as HEMA [7][8][9][10][11][12]15], and crosslinkers such as poly (ethylene glycol) dimethacrylate [16], and poly(ethylene glycol) diacrylate [17]. The co-polymerization of HEMA, acrylamide (AAm) and a suitable crosslinker provides a unique combination of properties of the resulting hydrogels, making them capable of swelling especially at high pH values [18][19]. Water-soluble photoinitiator systems for vinyl polymerizations, above all those active in the visible region of the spectrum, have gained increasing interest in recent years [20].…”