Methacrylate networks

Siloxane-(methyl methacrylate) networks showing high oxygen permeabilities were prepared by gamma-irradiation of tx,(o-methacryloyl terminated tetramethyl-disiloxanes and methyl methacrylate 325). Due to the utilization of very low molecular weight disiloxane modifier, no phase separation was observed in the networks produced. DSC studies showed only one Tg around 120 °C. These materials were evaluated... 

Fig. 5. Dependence of the swelling ratio X and modulus G (gem-2) on the acetone content a (vol %) for poty(acrylamide/sodium methacrylate) networks A-F in the mixture acetone-water. The molar fractions x, = 0, 0.004, 0.008, 0.012, 0.016 and 0.024 for series A,B,C,D.E and F, respectively (O) X ( ) G. From Ref. [11]...

Fig. 15. The relation between q0 and the second virial coefficient Ae for a number of poly(methyl methacrylate) networks in various diluents (acetone, toluene, benzene and chloroform). The first number in the code refers to the concentration of methyl methacrylate in the solution before polymerization, the second to the tenfold percentage of divinylbenzene added (by volume of methyl methacrylate) [Rijke...

Borovik s group studied the concept of cobalt complexes in a polymeric matrix as sensor in more detail. Four-coordinated Co(II) metal centers were incorporated into a porous methacrylate network by copolymerization of a styrene-substituted cobalt(II)(salen) complex with ethylene glycol dimethacrylate (see Figure 3) [19]. These complexes were specifically studied for their sensor capacity for NO [20]. 

Figure 4 shows that the formation of the methacrylic network is also somewhat influenced by the amount of OcSn, though a 100% conversion is always reached after about two hours. This observation may be related to the viscosity of the reaction medium its increase accelerates the radical copolymerization. The already mentioned OcSn-AIBN interaction has a similar effect, by inducing a faster decomposition of AIBN into radicals (Tabka, M. T. Widmaier, J. M. Meyer, G. C., to be published). 

Many approaches have been developed for the production of ionic liquid-polymer composite membranes. For example, Doyle et al. [165] prepared RTILs/PFSA composite membranes by swelling the Nafion with ionic liquids. When 1-butyl, 3-methyl imidazolium trifluoromethane sulfonate was used as the ionic liquid, the ionic conductivity ofthe composite membrane exceeded 0.1 S cm at 180 °C. A comparison between the ionic liquid-swollen membrane and the liquid itself indicated substantial proton mobility in these composites. Fuller et al. [166] prepared ionic liquid-polymer gel electrolytes by blending hydrophilic RTILs into a poly(vinylidene fiuoridej-hexafluoropropylene copolymer [PVdF(HFP)] matrix. The gel electrolytes prepared with an ionic liquid PVdF(HFP) mass ratio of 2 1 exhibited ionic conductivities >10 Scm at room temperature, and >10 Scm at 100 °C. When Noda and Watanabe [167] investigated the in situ polymerization of vinyl monomers in the RTILs, they produced suitable vinyl monomers that provided transparent, mechanically strong and highly conductive polymer electrolyte films. As an example, a 2-hydroxyethyl methacrylate network polymer in which BPBF4 was dissolved exhibited an ionic conductivity of 10 S cm at 30 °C. 

BMA and EGDMA monomers and UV-initiated polymerization to generate a cross-linked poly(methacrylate) network in the POPC bilayer. The substrate, ampicillin, diffused into liposomes through the OmpF channels and was converted to ampi-cillinoic acid. Thus a polymer-stabilized, vesicle-sized bioreactor with selective permeability was created, allowing for retention of the enzyme and ingress/egress of substrate and product. 

Goel, S. K. and Beckman, E. J. Plasticization of poly (methyl methacrylate) networks by supercritical carbon dioxide, Polymer, 34,1410-1417. 

Hexagonal array of microlenses fabricated by withdrawal method to apply liquid monomer. The lenses consisted of a cross linked poly-alkyl-methacrylate network. Lens diameter = 90 im. Focal length = 870 30 gm. Source Moench, W. and H. Zappe. 2004. Journal of Optics A, 6(4), 330-337. With permission.)... 

Doherty, D.C. et al. (1998) Polymerization molecular dynamics simulations. I. Cross-linked atomistic models for poly (methacrylate) networks. Comput. Theor. Polym. Sci. 8 (1-2), 169-178. 

Table II. Pore Diameters (Dp) of Porous Methacrylic Networks as Determined by SEM and Thermoporometry...

Alves, N. M., Gomez Ribelles, J. L., Gomez Tejedor, J. A., and Mano, J. F. (2004). Viscoelastic behavior of polyfnrethyl methacrylate) networks with different cross-linking degrees. Macromolecules 37, 3735. 

Preceding data have already shown the influence of the constituent networks on the formation of each network in IPNs. Chemical aspects of the formation of IP Ns were discussed in detail by Widmaier and Meyer [283]. They considered the synthesis of in situ sequential PU/PMMA IPNs, including the kinetics of formation of the PU and methacrylic network. The rates of polymerization Rp were deduced from the slopes of the conversion vs time curves. All the parameters influencing the kinetics of the methacrylic system, i.e., PU content, cross-Hnk density, and temperature were studied. The authors constructed the rate vs conversion profiles for all investigated systems. 

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