N-Isopropylacrylamide

The semi-interpenetrating polymeric networks obtained by the radical-induced polymerization of N-isopropylacrylamide in the presence of chitosan using tetraethyleneglycoldiacrylate as the cross-linker were used as controlled release vehicles for pilocarpine hydrochloride [294]. 

Hofkens, J., Hotta, J., Sasaki, K., Masuhara, H. and Iwai, K. (1997) Molecular assembling by the radiation pressure of a focused laser beam Poly (N-isopropylacrylamide) in aqueous solution. Langmuir, 13, 414-419. 

Irk, Af. Stimuli-Responsive Poly(N-isopropylacrylamide), Photo- and Chemical-Induced Phase Transitions. VoL 110, pp. 49-66. 

Liang, D., Zhou, S., Song, L., Zaitsev, V. S., and Chu, B., Copolymers of poly(N-isopropylacrylamide) densely grafted with poly(ethylene oxide) as high-performance separation matrix of DNA, Macromolecules, 32, 6326, 1999. 

BG Kabra, SH Gehrke. Synthesis of fast response poly(N-isopropylacrylamide) gels. Polym Commun 32 322-323, 1991. 

R Kishi, O Hirasa, H Ichijo. Fast responsive poly(N-isopropylacrylamide) hydrogels prepared by gamma-ray irradiation. Polym Gels Networks 5 145-151, 1997. 

SH Gehrke, LH Lyu, MC Yang. Swelling, shrinking, and solute permeation of temperature-sensitive N-isopropylacrylamide gel. Polym Prepr 30 482-483, 1989. 

CA Cole, SM Schreiner, JH Priest, N Monji, AS Hoffman. Lower critical solution temperatures of aqueous copolymers of N-isopropylacrylamide and other N-substi-tuted acrylamides. ACS Symp Ser 350 255-284, 1987. 

Table 1 Characteristics of graft copolymers of poly(N-isopropylacrylamide) (PNIPAM) and poly(ethylene oxide) (PEO) [165-167,170]...

Polymers BA Butylacrylate, CHP 3-chloro-2-hydroxypropyl, DADMAC Diallyldimethylammonium chloride, DMAEA Dimethylaminoethylacrylate,DMAEM Dimethylaminoethylmethacrylate, EM Epichlorohydrin Modified, EIMAOETMAC Hydroxymethacryloxyethyltrimethylammoniumc chloride, MAOEDMAC Methacryloxyethyldimethylammonium chloride, MAOETMAC Methacryloxyethyltrimethylammonium chloride, MDMAEM Methyldimethylaminoethylacrylate, M2VP l-methyl-2-vinylpyridinium bromide,M4VP l-methyl-4-vinylpyridinium bromide,NIPAM N-isopropylacrylamide,PEI Polyethyleneimine, Q Quaternary, VBTMAC Vinylbenzyltrimethylammonium chlroide,VP Vinylpyridinium. 

The team of Crooks is involved in the synthesis and the use of dendrimers and, more particularly, poly(amidoamine) dendrimers (PAMAM), for the preparation of dendrimer-encapsulated mono- or bimetallic nanoparticles of various metals (Pt, Pd, Cu, Au, Ag, Ni, etc.) [55, 56]. The dendrimers were used as nanocatalysts for the hydrogenation of allyl alcohol and N-isopropylacrylamide or other alkenes under different reaction conditions (water, organic solvents, biphasic fluorous/or-ganic solvents or supercritical COz). The hydrogenation reaction rate is dependent on dendrimer generation, as higher-generation dendrimers are more sterically... 

Grafting can also provide the monolithic polymers with rather unexpected properties. For example, the two-step grafting procedure summarized in Fig. 7, which involves the vinylization of the pore surface by reaction of the epoxide moiety with allyl amine, and a subsequent in situ radical polymerization of N-isopropylacrylamide (NIPAAm) initiated by azobisisobutyronitrile within these pores leads to a composite that changes its properties in response to external temperature [76]. 

Fig. 7. Grafting of a poly(glycidyl methacrylate-co-ethylene dimethacrylate) monolith with N-isopropylacrylamide...

Bergbreiter reported that poly(N-isopropylacrylamide)-bound phosphine ligands (PNIPAM-resins) coordinated with the Pd(0) moieties afford efficient catalysts (46) for the Heck, Suzuki and sp-sp cross-coupling reactions (Scheme 4.30) [122]. 

Scheme 5 Polyvalent hydrogen bonding of a a soluble poly(N-isopropylacrylamide) to a 3-PAA/PE hyperbranched graft or b a soluble poly(acrylic acid) to a hyperbranched poly(Ar-isopropylacrylamide) graft on PE...

Poly(N-isopropylacrylamide) (polyNIPAAM), formed by a free radical polymerization of N-isopropylacrylamide, is a water soluble, temperature sensitive polymer. In aqueous solution, it exhibits a lower critical solution temperature (LCST) in the range of 30-35 C depending on the concentration and the chain length of the polymer. Thus, as the solution temperature is raised above the LCST, the polymer undergoes a reversible phase transition characterized by the separation of a solid phase which redissolves when the solution temperature is lowered below the LCST. Its physicochemical properties have been investigated by several laboratories (1-3). 

The first step in the process was to covalently incorporate biologically active protein molecules into this polymer. Methods analogous to previous reports (4-6) involved first adding a functional group to the protein that would provide it with the ability to polymerize, such as a vinyl or substituted vinyl group, followed by copolymerization with the N-isopropylacrylamide monomer in aqueous solution using N,N,N, N -tetramethylethylenediamine and... 

---