Photopolymerization ethyl acrylate

A more conventional mechanism appears to be operative in the photopolymerization of ethyl acrylate [178] and methyl methacrylate [179] in aqueous solution, sensitized by fluorescein and Erythrosin, respectively. Ascorbic acid is the reducing agent in both cases and it is observed that the reaction does not proceed in the absence of buffer, usually phosphate buffer pH 6. Polymer formation starts after an induction period but its dependence on light intensity and ascorbic acid concentration has not been determined. The rate of photopolymerization is proportional to the monomer concentration and to the square root of the light intensity, dye, and ascorbic acid concentration. The authors report the order with respect to the monomer as 3/2. However, from our analysis of the data for fluorescein, which are more... 

Oxygen is less effective in inhibiting polymerizations of acrylic esters. It reacts 400 times faster with the methacrylic radicals than with the acrylic ones. Nevertheless, even small quantities of oxygen affect polymerization rates of acrylic esters. This includes photopolymerizations of gaseous ethyl acrylate that are affected by oxygen and by moisture. ... 

Ethyl acrylate Tetraethylene glycol Benzoin uv photopolymerization Thermal polymerization with 1... 

Methyl TEGDM Benzoin uv photopolymerization Isomeric with ethyl acrylate. 1... 

In the anthraquinone-sensitized photopolymerization of acrylate monomers, the percent conversion depends markedly on the nature of the solvent as well as on the type of monomer. Ethyl and n-butyl methacrylate, for example. 

Indeed, photopolymerization of acrylamide in aqueous solution on cell-GEHMP gives cellulose with the surface covered by a poly acrylamide) gel. Similarly, UV initiated polymerization of 2-hydroxyethyl acrylate, 2-(dimethylamino) ethyl methacrylate and A -vinylpyrrolidone carried out with the above functionalized Si(>2 results in the formation of a surfece polymer coating. 

Dai, Q.G. Gilbert, R.D. Khan, S.A. Kadla, J.F. Relaxation behaviors of lyotropic (acetyl)(ethyl) cellulose/acrylic acid solutions with different chiro-optical properties. Polym. Preprints (ACS, Div Polym. Chem.) 2004, 45 (1), 824-825. Shimamoto, S. Uraki, Y. Sano, Y. Optical properties and photopolymerization of liquid crystalline (acetyl) (ethyl) cellulose/acrylic acid system. Cellulose 2000, 7 (4), 347-358. 

Photopolymerization in the vapour phase has been observed on surfaces exposed to u.v. radiation in the presence of six fluorocarbon monomers.34 Ionic polymerization of vinyl halides in the vapour phase has been initiated by photoionization using photons with energies near the ionization threshold,35 and the photochemical initiation of polymerization of gaseous ethyl acrylate35 and MM A, butyl acrylate, and methacrylates under high pressures37 has been reported. The last study utilized l,r-azocyclohexane carbonitrile as photosensitizer. 

Oxman et al., smdied controlled, sequentially curable cationic/free radical hybrid photopolymerization of diepoxide/acrylate hybrid material with the aid of photodifferential scanning calorimetry. The polymerizations were carried out in the presence of various concentrations of either ethyl-4-dimethylamino benzoate or 4-tert-butyl-N,N,-dimethylaniline as electron donors and camphoquinone/diphenyliodonium hexafluoroantimonate as the sensitizing system. The results showed that the free-radical acrylate reactions always precede the cationic epoxy polymerizations. 

A combination of benzophenone and 1,3-dioxane is a convenient hydrogen abstraction-type photoinitiator system for the free radical photopolymerization of methyl methacrylate, styrene and other monomers. As an advantage, this system does not require an additional hydrogen donor as other conventional initiators. In a similar way, mixtures of thioxanthone derivatives and fluorenes can be used as visible light absorbing oil- and water-soluble photoinitiators for free radical polymerization of methyl methacrylate, ethyl 2-(2-phosphonoethoxymethyl)acrylate and trimethylolpropane triacrylate. Photopolymerization and laser flash photolysis studies reveal that initiation occurs by intra- and intermolecular hydrogen abstraction by the thioxanthone-like triplet excited state. 

For the investigated photopolymerization-induced banded texture of ethyl-cya-noethyl cellulose/acrylic acid/copper acrylate cholesteric liquid crystalline solutions, the results indicate that the cholesteric liquid crystal phase can be fixed through photopolymerization. 

---