2-Hydroxyethyl methacrylate ability

The first soft contact lenses were also constructed with a polymeric material containing a single monomeric unit. The added pliability of the soft lens was derived from the more hydrophilic nature of the monomer, enhancing the ability of the polymer to absorb water and provide greater comfort to the lens wearer. This monomer is a derivative of MMA known as hydroxyethyl methacrylate (HEMA). A number of hydrophilic monomers are used in soft lenses today these materials are referred to as hydrogels because of their ability to absorb significant amounts of water yet remain insoluble. 

Terbutylazine was another example of a triazine herbicide, which was used for MIP synthesis. In otdet to test the ability of different functional monomers to form strong interactions with terbutylazine, a combinatorial approach was used. Thus, MAA, 2-(trifluoromethyl) acrylic acid (TFMAA), hydroxyethyl methacrylate (HEM), methyl methacrylate (MMA), N-vinyl-a-pytrolidone (NVP) and 4-vinylpytidine (4VP) were used for polymer preparation. In dichloromethane, MAA and TFMAA appeared to be the best monomets able to fotm the terbutilazine-specific functional sites. 

Many graft copolymers have been made by free radical copolymerization of co-styryl or co-methacryloyloxy macromonomers and various comonomers. Special interest has been devoted to amphiphilic copolymers involving a hydrophilic backbone and hydrophobic grafts, or vice versaf Poly(perfluoroalkyl methacrylate) and poly(stearyl methacrylate) are typical examples of hydrophobic polymers, whereas poly(hydroxyethyl methacrylate) or poly(vinylpyrrolidone) are examples of nonionic hydrophilic chains. Such graft copolymers have found a number of applications as surface modifiers or coatings because of their ability to give intramolecular phase separation (surface accumulation phenomena ). 

A change in the hydrophilic nature of the polymer surface on irradiation of poly(p-phenylazoacrylanilide) or its copolymer with 2-hydroxyethyl methacrylate (HEMA) could affect the adsorption-desorption behavior of proteins or organic substances onto the polymer. Adsorption of lysozyme onto the copolymer of p-phenylazoacylanilide and HEMA decreased from 4.6 to 1.8 eg g of adsorbent on UV irradiation, which induces the isomerization from trans- to cis-form [16]. Table 2 summarizes the results of other proteins adsorption studies. Considering the similarity in molecular weight of the three proteins, the difference in adsorption behavior is probably due to the difference in the surface characteristics of these proteins. The decrease in adsorption ability on UV irradiation is attributable to the reduction of hydrophobic interaction between the protein and the polymer by the appearance of hydrophilic cis-azobenzene on the surface. 

Novikova et al., reported that some pentaaza-1,4-dienes can photo initiate polymerization. Thus, l,5-Bis(4-methoxyphenyl)-3-methyl-l,4-pentazadiene, l,5-diphenyl-3-(2-hydroxyethyl)-l,4-pentaza-diene, and 1,5-diphenyl-3-methyl-l,4-pentazadiene were used as photoinitiators of radical polymerization of hexanediol diacrylate and of methyl methacrylate. Photoinitiation abilities of these compounds were compared with those of a commercial photoinitiator, Irgacure 1700. The pentaazodienes showed a high initiation capacity. Also, the activation energy of the polymerization in the presenee of the pentaazodiene compounds was lower than that for Irgacure 1700. 

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