- Hydroxy functional acrylate and methacrylate monomers prepared via lipase-catalyzed transacylation reactions
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Candida antarctica lipase B (CAL-B, Novozyme 435) catalyzes the transacylation of methyl acrylate and methyl methacrylate with diols and triols in 2-methyl-2-butanol at 50 °C. Under the experimental conditions, up to 70 mol% of the acyl donor methyl acrylate was converted. Methyl methacrylate is the less efficient acyl donor (up to 60 mol%) due to the higher sterical hindrance in the enzymatic transacylation. Under the reaction conditions high yields of the mono-acylated products are obtained, which contain minor amounts of bis(meth)acrylates. In addition it was observed that Novozyme 435 catalyzes regioselectively the acylation of the primary hydroxyl groups. In comparison with the chemical catalyzed route no selectivity was observed for unsubstituted diols. For substituted diols more mono-acylated product was formed in the lipase-catalyzed reaction than in the chemical catalyzed reaction.
- Popescu, Dragos,Hoogenboom, Richard,Keul, Helmut,Moeller, Martin
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experimental part
p. 80 - 89
(2010/08/20)
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- Free radical and nitroxide mediated polymerization of hydroxy-functional acrylates prepared via lipase-catalyzed transacylation reactions
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3-Hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 2-methyl-3-hydroxypropyl acrylate, 2-hydroxypropyl acrylate, neopentyl glycol acrylate, glyceryl acrylate, and dihydroxyhexyl acrylate were prepared via transacylation reaction of methyl acrylate with diols and triols catalyzed by Candida antarctica lipase B. After removal of the enzyme by filtration and the methyl acrylate by distillation, the monomers were polymerized via free radical polymerization (FRP) with azobisisobutyronitrile as initiator and nitroxide mediated polymerization (NMP) employing Blocbuilder alkoxyamine initiator and SG-1 free nitroxide resulting in hydroxy functional poly(acrylates). The NMP kinetics are discussed in detail. In addition, the polymers obtained by FRP and NMP are compared and the results are related to the amount of bisacrylates that are present in the initial monomer mixtures resulting from the transacylation reactions
- Popescu, Dragos,Hoogenboom, Richard,Keul, Helmut,Moeller, Martin
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experimental part
p. 2610 - 2621
(2011/04/22)
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- Wet adhesion promoter
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Compositions containing urea functional compounds are disclosed which are particularly suitable for use as post-added wet adhesion promoters in coatings, especially in aqueous emulsion systems used to make latex paints. A process of preparing the same is also disclosed, as well as a novel class of compounds.
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