Cross-linking monomers trimethacrylate

In the next step, an excess of cross-linking monomer (e.g. trimethylol-propane trimethacrylate or ethylene glycol dimethacrylate) is added together with an initiator (e.g. 2,2 -azoisobutyronitrile), which induces the polymerisation process. Under nitrogen and high temperature, the polymerisation process results in the formation of a rigid mass of polymer. 

The template, the functional monomers and the cross-linking monomers are dissolved in a non-polar solvent. The functional monomers and the template form complexes and the strength of these are reflected in the selectivity of the imprinted polymer. The choice of functional monomer is based on the template structure. Functional monomers are chosen for their ability to interact non-covalently with the template molecule. The most frequently used functional monomer so far is methacrylic acid (MAA). Also vinylpyridines have been frequently used. As cross-linking monomers, ethyleneglycol dimethacrylate (EDMA) or trimethylolpropane trimethacrylate (TRIM) are widely used. Several other types of functional and cross-linking monomers have been used in molecular imprinting experiments using the non-covalent approach. The choice of monomers is of course important to the... 

Figure 5 Selection of common cross-linkers used in molecular imprinting protocols. Both ethyleneglycol dimethacrylate (EDMA) and divinylbenzene (DVB) are very common crosslinkers in molecular imprinting. Other acrylate-based cross-linking monomers conunonly used include the branched cross-linker trimethylolpropane trimethacrylate (TRIM)-[24]. Among the water-soluble cross-linkers, there are phenylene-diacrylamide, V,V-methylene diacrylamide [22], and Z w-acryloylpiperazine [92], which have been used in aqueous systems for the imprinting of, e.g., enzymes.

Unfortunately, the commonly used imprinting solvents such as chloroform and toluene may not work for all systems. For example, in preparing an CEC monolith composed of functional monomers MAA, cross-linking monomer trimethylolpro-pane trimethacrylate (TRIM), and radical initiator 2,2 -azobis(isobutyronitrile) (AIBN), Schweitz et al. found that the use of toluene as the only porogenic solvent failed to produce sufiSciently porous monoliths [34]. The polymers produced using toluene were very dense and hydrodynamic pumping was not possible. Under these... 

Copolymerization of di- and trimethacrylates with functionalized monomers, like glycidyl methacrylate, leads to low-viscosity oligomers capable of nonradical cross-linking. This process promises substantial value for industrial applications. Star polymers useful in coatings were prepared by copolymerizing methacrylate macromonomers with diacrylates.519 For instance, a star polymer was synthesized by copolymerization of a 2-ethylhexyl methacrylate/isobutyl methacrylate/hydroxyethyl methacrylate macromonomer with butanediol diacrylate. 

Oliva et al. [23] describe the EPR characterization of radicals trapped during the photoinitiated polymerization of trimethacrylate monomer (TMA), which leads to a highly cross-linked polymer structure also, vinylmethacrylate monomer (VMA), a difunctional monomer carrying different reactive groups, has been studied. The EPR spectra obtained at room temperature from photoinitiated samples of both trimethacrylate monomer TMA and vinylmethacrylate monomer VMA consist of a nine-line EPR pattern, typical of methacrylate propagating radicals (Structure I). 

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