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Foaming Chemistry and Physics
Published in Leslie R. Rudnick, Lubricant Additives, 2017
Kalman Koczo, Mark D. Leatherman, Kevin Hughes, Don Knobloch
Polyacrylate antifoams are typically synthesized via chain-growth polymerization of a mixture of alkyl acrylate monomers in hydrocarbon solvent or oil [118,138] (see Figure 19.21). Commonly, the polymerization is initiated by a peroxide or other free radical source, although examples of cationic and anionic polymerization are also known. The selection of monomer mixture is based on the solubility properties of the intended lubricating fluid and typically includes linear and branched short-chain alkyl acrylates ranging from C2 to C12. A common example is a copolymer of ethyl acrylate and 2-ethylhexyl acrylate [120]. There are also examples of incorporating functionalized acrylate monomers, for example, 2,2,2-trifluoroethyl acrylate [128].
Chemicals from Olefin Hydrocarbons
Published in James G. Speight, Handbook of Petrochemical Processes, 2019
Derivatives of acrylic acid (butyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate, and methyl acrylate) can be homopolymerized using peroxide initiators or copolymerized with other monomers to generate acrylic or aclryloid resins.
PolyHIPEs for Separations and Chemical Transformations: A Review
Published in Solvent Extraction and Ion Exchange, 2019
Kathryn M. L. Taylor-Pashow, Julia G. Pribyl
In another example of reinforced polyHIPE materials, polyHIPEs prepared from styrene/2-ethylhexyl acrylate/DVB were reinforced with silica nanoparticles that were introduced into the organic phase during the initial formation of the HIPE in various amounts from 1–5 wt %.[24] The 2-ethylhexyl acrylate co-monomer was selected for its low glass-transition temperature, which imparts lower brittleness and volume shrinkage to the resultant polymer. The incorporation of silica nanoparticles imparts increased compressive Young’s modulus and crush strength. After preparation, the polyHIPEs were treated with sulfuric acid to introduce cation-exchange sites. The IECs of the materials were found to increase with increasing incorporation of silica nanoparticles up to 3 wt %, above which the IEC began to drop. The IEC of material with 3 wt % silica nanoparticles was 3.9 mequiv/g. The materials were also evaluated for Ni2+ removal by ion exchange across the pH range 2–10, and maximum removal was found at pH 6 where 99% of the nickel ions were adsorbed (25 mg/L initial Ni2+ concentration and 0.4 g adsorbent per 100 mL).