2-Hydroxyethyl methacrylate effect

As a result, zones A, B, and C have comparatively a basic, neutral, and acidic character, respectively. Increasing the DC electric current leads to the overall acidification of the gel sample (see Fig. 6, curve 4) due to the easy ionization of the acidic groups. Consequently, this narrows the zones B and C and expands zone A. Polybetaine hydrogel membranes of isopropyl-2-[2 -(trimethylammonium)ethyl phosphoryl] ethyl fumaramate and 2-hydroxyethyl methacrylate effectively enhance the water content in comparison with poly(2-hydroxyethyl methacrylate) [224]. The content of water in hydrogel membranes increases, but the amount of adsorbed BSA decreases with the increase of the betaine content in the feed. The values of the tensile strength and tensile elongation of the hydrogel reach 68.4 g mm and 239%, respectively. 

The effect of Fe(II) on grafting of 2-hydroxyethyl methacrylate onto polyester fibers in the presence of benzoyl peroxide was investigated [59]. It was found that increasing the iron ion concentration decreases the graft yield. This suggest that excess Fe(ll) ions participate in the generation of free radical species and the iron ions seem to contribute to the termination and, consequently, decrease the graft yield. 

D Biren, BG Kabra, SH Gehrke. Effect of initial sample anisotropy on the solvent sorption kinetics of glassy poly(2-hydroxyethyl methacrylate). Polymer 33 554-561, 1992. 

The effect of hydrophobicity of the polymer on the permeability of poly(2-hydroxyethyl methacrylate (HEMA)-co-methacrylic acid (MAAc) hydrogels was studied [12], The hydrophobicity was controlled by copolymerization with butyl methacrylate (BMA). The dependence of permeability on pH increased as the hydrophobicity increased even though the rate of diffusion decreased. Cross-link density of the hydrogel also contributed to pH-dependent permeability. 

The Effects of Initiator and Diluent on the Photopolymerization of 2-Hydroxyethyl Methacrylate and on Properties of Hydrogels Obtained... 

In contrast, monolithic materials are easily amenable to any format. This has been demonstrated by using short monolithic rods prepared by copolymerization of divinylbenzene and 2-hydroxyethyl methacrylate in the presence of specifically selected porogens [93]. Table 2 compares recoveries of substituted phenols from both the copolymer and poly(divinylbenzene) cartridges and clearly confirms the positive effect of the polar comonomer. 

Fig. 8. Effect of the comonomer volume fraction vH on the Tr depression of 2-hydroxyethyl methacrylate Acrylic add ( ), methacryfic add (O), acrylamide (9), methacrylamide ( ), acrylonitrile ( ), meth-acrylonitrile ( ), and methyl methacrylate ( )...

Fiq. 10 a, b. Effect of the comonomer volume fraction vH on (a) the relative height and (b) the relative storage modulus decrement of the low-temperature dispersion of 2-hydroxyethyl methacrylate (symbols as in Fig. 8)... 

Fig. 12. Effect of the volume fraction of methacrylic acid on the temperature dependence of the shear loss modulus of copolymers with 2-hydroxyethyl methacrylate 1 = 0.00 2 = 0.14 3 = 0.39 4 = 0.72 5 = 1.00...

Fig. 14. Effect of the volume fraction of ethylene glycol on the temperature dependence of the shear storage and toss moduli of poly(2-hydroxyethyl methacrylate) 1 = 0.15 2 = 0.33 3 = 0.47 4 = 0.58 5 = 0.76 6 = 0.84...

Fig. 15. Effect of the diluent volume fraction on the temperature of the T and T d dispersions of poly(2-hydroxyethyl methacrylate) Ethylene glycol (—, O) formamide (-.-, 3) water (—, ) propanol (..., >). The curves have been calculated according to Eq. (13), for the system PHEMA-water drawn through experimental points...

Fig. 6.23. Effect of thermal (a) and UV initiation (b), type of comonomer, and percentage of 1-dodecanol in the polymerization mixture on the mode pore diameter of quinidine-functionalized chiral monoliths. (Reprinted with permission from [56]. Copyright 2000 American Chemical Society). Reaction conditions polymerization mixture, chiral monomer 25 8 wt%, glycidyl methacrylate ( ) or 2-hydroxyethyl methacrylate ( ) 16 wt%, ethylene dimethacrylate 16 wt%, porogenic solvent 60 wt% (consisting of 1-dodecanol and cyclohexanol), polymerization time 20 h at 60°C (a) and 16 h at room temperature (b).

Photoinitiated polymerization of the same mixtures at 20°C generally yields monoliths with larger pores compared to those initiated thermally. Thus, reduced contents of dodecanol in the polymerization mixture has to be used for UV initiated polymerizations in order to obtain pore sizes comparable to those of their thermally polymerized analogs. For example, a polymerization mixture containing only 30% dodecanol can be used to produce a 2-hydroxyethyl methacrylate monolith with 1,000 nm pores by UV polymerization at 20°C. These shifts can readily be explained by the effect of the polymerization temperature, since the creation of larger pores is favored at lower temperatures [59],... 

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