Synthesis and characterization of fluorocarbon-modified poly(N-isopropylacrylamide)

Abstract

Poly(N‐isopropylacrylamide) copolymers (PNIPAMs) containing pendent perfluoroalkyl (RF) or dodecyl groups have been synthesized by copolymerization of NIPAM with small amounts of RR‐acrylates or ‐methacrylates containing a sulfonamido moiety between the acrylate and RF groups or with dodecyl acrylate. Evidence for strong intermolecular hydrophobic association of the fluorocarbon groups is provided by large viscosity increases with copolymer concentration and upon addition of NaCl and surfactants. These interactions appear to be much stronger than that of the corresponding copolymers of poly(N,N‐dimethylacrylamide) with similar comonomer contents. Hydrophobic association between the RF groups is found to be much stronger than that of the corresponding dodecyl groups. The viscosity of some of the copolymer solutions, particularly in the presence of perfluorocarbon surfactants, was unusually temperature sensitive, decreasing by a factor of at least 1000 upon increasing the temperature from 10 to 20 °C. This large decrease is most probably related to the collapse of the copolymer coils near the lower critical solution temperature. This is in sharp contrast to the corresponding polyacrylamide or poly(N,N‐dimethylacrylamide) RF‐acrylate copolymers that show viscosity increases with increasing temperature in the 40–60 °C range. The NIPIAM copolymers were also found to be different from the acrylamide or N,N‐dimethylacrylamide perfluorocarbon acrylate copolymers in that they were found to be Newtonian at a low RF content but dilatant at a higher comonomer content. © 2000 Society of Chemical Industry

Novel Synthesis and Characterization of Side-Chain Ferrocene-Containing Polymers

“…Poly( N -isopropylacrylamide) (PNIPAM) is a thermally sensitive polymer with a low critical solution temperature (LCST) of ∼32 °C; − namely, it is hydrophilic and soluble in water at temperatures lower than 32 °C but becomes hydrophobic and insoluble at higher temperatures. − The incorporation of PFEMAA into PNIPAM enables us to adjust the average interdistance between ferrocene groups by a simple temperature variation. All three copolymers were soluble in water at room temperature because of a low content of PFEMAA.…”

Asymmetric End-Capped Poly(ethylene oxide). Synthesis and Rheological Behavior in Aqueous Solution

“…Interest raised by fluorocarbon APs comes from the low surface energy and hydrophobic properties of fluorinated substituents but also from the considerably enhanced viscosifying properties . The degree of substitution has to stay low (a few units per chain) in order to maintain solubility of fluorinated APs in water. , Among the various classes of APs, hydrophobically end-capped poly(ethylene oxide) (PEO) present a well-defined architecture. Because of the known position of hydrophobic groups at each end of the polymer chain, these telechelic APs can be used as model systems for fundamental and systematic studies …”

Effect of multiwall carbon nanotube and au nanoparticle on the structure–property relationship of poly(N‐isopropyl acrylamide)

“…Core‐shell microgels of PNIPAAm/poly(viny alcohol) were synthesized and characterized by zeta potential, scanning electron microscopy (SEM), transmission electron microscopy (TEM), nuclear magnetic resonance spectroscopy (NMR), and turbidity measurements 10. Other authors also reported about the synthesis and characterizations of PNIPAAm 11–25. By thorough literature survey, we could not find any report based on the copolymerization of vinyl functionalized nanomaterials like Au and multiwall carbon nanotube (MWCNT) with N ‐isopropylacrylamide (NIPAAm) in the presence of peroxydisulphate (PDS) as a free radical initiator.…”