Acrylic acid Catalyst dispersion

The important role Transmission Electron Microscopy (TEM) can play in this process is demonstrated on the development of an oxidation catalyst for the production of acrylic acid. Acrylic acid is produced by BASF in quantities of several 100.000 tons per year in a two step gas phase oxidation process starting from propene, which is oxidised to acrolein in the first step and then further oxidised to acrylic acid in a second step, each step requiring a special developed catalyst. Acrylic acid is used as a base material for the production of superabsorbents for nappies, dispersions and emulsions for adhesives and construction materials. 

With a rhodium complex catalyst containing a chiral ligand dispersed in [BMIM]SbFg, the enantioselective hydrogenation of a-acetamidocinnamic acid to (5)-phenylalanine was achieved with 64% enantiomeric excess 112). [RuCl2( S)-BINAP]2 NEt3 in [BMIM]BF4 for (5)-naproxen synthesis gave 80% ee from 2-(6-methoxy-2-naphthyl) acrylic acid and isopropyl alcohol 214). 

Synthesis can be by solvent or emulsion polymerization. Solvent polymerization involves dissolving the monomer or monomer mixture in a solvent such as ethyl acetate, benzene, or toluene. Polymerization occms through the addition of a free radical initiator such as a soluble organic peroxide. Emulsion polymerization involves adding water, emulsifier, and acrylic acid (neutralized to pH 7 to 8), any comonomers, and a catalyst. A typical latex dispersion is 50% solids, polymer particle size 0.3 mm and a viscosity of 20 mPa.s. 

Similarly, cobalt(ll)-pyridine (CoPy) complexes bound to copolymers of styrene and acrylic or methacrylic acid, cross-linked with divinylbenzene, catalyze the autoxidation of tetralin dispersed in water at 50°C and 1 bar.45 The rate of oxidation with the colloidal CoPy catalyst was twice as fast as with homogeneous CoPy and nine times as fast as with cobalt(II) acetate in acetic acid. 

The Texanol and Dowanol PM are added slowly to the epoxy dispersion under agitation and are mixed together for 20 minutes. The crosslinker E 3747) is a fully methylated melamine (HMMM) of low viscosity, however without the presence of a coupling solvent (or co-solvent), such as butanol, it is not water dispersible. The acid functionality of the epoxy acrylic will act as an internal catalyst, because fully methylated melamines require acid catalysis for optimum properties to be achieved. The crosslinker is added to the dispersion under maximum agitation, so that it enters the dispersion at the centre of the agitator s vortex. The mixture is agitated continuously for a further 40 minutes. The dispersion is then adjusted to the final solids, and viscosity by the careful addition of DIW, and tertiary amine to reach the solids and viscosity required. 

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