ISOPROPYL ACRYLAMIDE

A -isopropyl acrylamide (N1PA VI) copolymerization by RAFT 529 JV-isopropyl acrylamide (Ml PAV1) polymerization block copolymers 543, 546 with dithiocarbamale photmnitiaior 465... 

Uenoyama, S and Hoffman AS. Synthesis and characterization of acrylamide-N-isopropyl acrylamide copolymer grafts on silicone rubber substrates. Radiat. Phys. Chem., 1988, 32, 605-608. 

Figure 6 The stress-strain behavior predicted by Eq. (16) is observed for /V-isopropyl acrylamide-co-sodium acrylate gel.

Figure 9 The equations of motion (TF theory) correlate swelling of poly(A-isopropyl acrylamide) caused by an increase in temperature from 10 to 25°C. D = 2.5 X 10 7 cm2/s L0 = 1.5 mm. (Adapted from Ref. 84.)...

Figure 14 The free volume theory of Yasuda and coworkers holds for the diffusion of acetaminophen in swollen 10 X 4 poly(lV-isopropyl acrylamide) gel. (Adapted from Ref. 176.)...

Figure 11 Aqueous equilibrium swelling of cross-linked poly(A-isopropyl acrylamide-co-butyl methacrylate) as a function of temperature. Ww, Wp are the weight of water and polymer of swollen polymer network respectively. (From Ref. 32.)...

Figure 17 Permeability of uranine ( ), dextran 4.4K (O), and dextran 150K (A) through cross-linked poly(/V-isopropyl acrylamide-co-butyl methacrylate, 95 5 mol%) membrane. Error bars represent standard deviation in the slope of the curve of the receiver concentration of solute as a function of time at steady state. (From Ref. 37.)...

Polydiallyldimethylammonium Chloride-co-N-Isopropyl Acrylamide 1.0-5.0 Synthesized by R. Pelton, McMaster Univ. 

Polydiallydimethylammonium Chloride-co-N-Isopropyl Acrylamide Medium Permanent Medium Flexible Cyclic Side Chain Weak... 

STRUCTURE AND SOLUTE SIZE EXCLUSION OF POLY(METHACRYLIC ACID)/POLY(A/-ISOPROPYL ACRYLAMIDE) INTERPENETRATING POLYMERIC NETWORKS... 

Structure and Solute Size Exclusion of Poly(methacrylic acid)/Poly(A -isopropyl acrylamide) Interpenetrating Polymeric Networks... 

Poly(A-isopropyl acrylamide) (PNIPAAm) is the most extensively studied temperature-sensitive polymer [10-20]. Crosslinked PNIPAAm exhibits drastic swelling transition at its lower critical solution temperature... 

The temperature-sensitive poly(A-isopropyl acrylamide) and pH-sensitive poly(methacrylic acid) were used as the two component networks in the IPN system. Since both A-isopropyl acrylamide (NIPAAm) (Fisher Scientific, Pittsburgh, PA) and methacrylic acid (MAA) (Aldrich, Milwaukee, Wl) react by the same polymerization mechanism, a sequential method was used to avoid the formation of a PNIPAAm/PMAA copolymer. A UV-initiated solution-polymerization technique offered a quick and convenient way to achieve the interpenetration of the networks. Polymer network I was prepared and purified before polymer network II was synthesized in the presence of network I. Figure I shows the typical IPN structure. 

Fig. 19. Turn-over frequencies for hydrogenation of allyl alcohol and N-isopropyl acrylamide obtained in water using dendrimer-encapsulated Pd nanoparticles of constant average size. The hydroxyl-terminated PAMAM dendrimer generation varies from G4 to G8...

An interesting family of polymeric ligands show inverse temperature dependence of solubihty in water, i.e. they can be precipitated from aqueous solutions by increasing the temperature above the so-called cloud point. Typically these ligands contain poly(oxyalkylene) chains, but the phenomenon can be similarly observed with poly(N-isopropyl acrylamide) derivatives (e.g. 132) and methylated cyclodextrins, too. At or above their cloud points these compounds fall off the solution, due to the break-up and loss of the hydration shell which prevents aggregation and precipitation of their molecules. Conversely, upon cooling below this temperature (also called the lower critical solution temperature, LCST) these substances dissolve again. 

The hyperbranched hydrogen-bond grafts formed in these self assembly processes are stable to solvent extraction. This was shown by preparing fluo-rescently labeled poly(N-isopropyl acrylamide) 11 and poly(acryhc acid) 12. 

Hydrogels synthesized from polymers and copolymers of N-isopropyl acrylamide (NIPAAm) shrink or swell as the temperature is raised or lowered through their lower critical solution temperature (LCST). 

We report here on copolymer hydrogels of N-isopropyl acrylamide (NIPAAm) and acrylamide (AAm) which are crosslinked with mediylene-bis-acrylamide (MBAAm) and which contain the enzyme asparaginase immobilized within the gel. 

High polymers of N-isopropyl acrylamide (NIPAAM) exhibit a lower critical solution temperature (LCST) in phosphate buffered saline above 31 C precipitation occurs, with minimal concentration dependence. 

Figure 1. Lower critical solution temperatures of copolymers of N-isopropyl acrylamide with other N-alkyl acrylamides as a function of monomer input ratios.

Figure 2. Sephacryl S-400 Chromatogram of Acrylamide/N-isopropyl Acrylamide (10/90) Copolymer.

Figure 3. Turbidity versus Temperature Curves for poly-N-isopropyl acrylamide and its copolymers ...

Figure 4. Copolymerization plot for acrylamide and N-isopropyl acrylamide (NIPAAM).

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