Synthesis and Characterization of Novel Poly(N-isopropylacrylamide-co-N,N′-dimethylaminoethyl methacrylate sulfate) Hydrogels

Abstract

Poly(N-isopropylacrylamide-co-N,N′-dimethylaminoethyl methacrylate sulfate) [P(NIPAM-co-DMAEMASA)] was prepared from N-isopropylacrylamide (NIPAM) and N,N-dimethylaminoethyl methacrylate sulfate (DMAEMASA) monomers, and its properties were compared with those of poly(N-isopropylacrylamide-co-N,N′-dimethylaminoethyl methacrylate) [P(NIPAM-co-DMAEMA)]. The copolymers were characterized by swelling measurements in distilled water (10-40 °C) and buffer solutions (I ) 0.1 M, pH ) 2.2-10.0), FTIR, DSC, and SEM methods. The ESV's of the NIPAM-DMAEMASA copolymers in distilled water were 5 times higher than those of P(NIPAM-co-DMAEMA); they decreased with an increase in comonomer (DMAEMASA/DMAEMA) content for both copolymers. While NIPAM-DMAEMASA copolymers did not display any phase transition with temperature, the LCST of the NIPAM-DMAEMA copolymer was determined as 20 °C. Both copolymers displayed a phase transition at pH ) 5.0, but the pH of the phase transition for NIPAM-DMAEMA gels shifted to 7.0 with increased DMAEMA content. Glass transition temperatures of NIPAM copolymers did not change with the type and content of comonomer.

Novel approaches for the preparation of magnetic nanogels via covalent bonding

“…The same effect was observed by Häntzschel et al in poly( N ‐vinyl caprolactam(VCL)‐ co ‐GM)‐based nanogels. As expected, the presence of a non‐responsive polymer led to a lower pH‐sensitivity . Moreover, it is well known that the pH‐responsiveness of polyelectrolyte‐based nanogels is governed by electrostatic interactions between the polymer chains, and therefore, it is determined by their charge density .…”

Effect of sodium hydroxide solution as polymerization solvent and activator on structural, mechanical and antibacterial properties of PNIPAAm and P(NIPAAm–clay) hydrogels

“…Conventional PNIPAAm hydrogels are commonly initiated with TEMED/APS (or TEMED/KPS) redox pair and prepared by using an organic crosslinker such as BIS in water at temperatures T < VPTT . However, their high swelling ratios/slow shrinking rates, optical turbidities and mechanical weaknesses limit their application areas.…”

Near‐infrared‐active and pH‐responsive fluorescent polymer‐integrated hybrid graphene oxide nanoparticles for the detection and treatment of cancer

“…The intensity of the band at 1469 cm −1 is attributed to the bending of the CH bond in CH( CH 3 ) 2 . The peak at 1549 cm −1 represents the tertiary amine of the DMA unit, and the peaks at 3450 and 2919 cm −1 are characteristic indicators of the BODIPY moiety . The band at 1521 cm −1 is ascribed to the stretching of CC and C‐C in the thiophene ring.…”