Acrylic acid commercial generators

Fig. 1 Chemical structures of the polymers commonly used for preparation of beads poly (styrene-co-maleic acid) (=PS-MA) poly(methyl methacrylate-co-methacrylic acid) (=PMMA-MA) poly(acrylonitrile-co-acrylic acid) (=PAN-AA) polyvinylchloride (=PVC) polysulfone (=PSulf) ethylcellulose (=EC) cellulose acetate (=CAc) polyacrylamide (=PAAm) poly(sty-rene-Wocfc-vinylpyrrolidone) (=PS-PVP) and Organically modified silica (=Ormosil). PS-MA is commercially available as an anhydride and negative charges on the bead surface are generated during preparation of the beads...

The mechanisms involved in monomer removal by post polymerisation were studied. Three redox initiator systans which generate radicals with different hydrophobidties were investigated tert-butyl hydroperoxide, hydrogen peroxide and potassium persulphate. Ascorbic acid was used as a reductant in all cases. The efficiency of these initiator systems for the removal of residual monomers from commercial latexes was studied. The examples exauuued were removal of unreacted vinyl acetate from a vinyl acetate/butyl aerylate/acrylie acid latex, methyl methacrylate from a methyl aaylate, butyl aaylate/acryhc acid latex and butyl acrylate from a butyl aaylate/styrene/ acrylic acid latex. Efficieucy of monomer ranoval by post polymerisation increased with the hydrophobidty of the radical formed from the initiator system and this was independent of the water solubihty of the residual monomer. Reasons for the observations were discussed. 35 refs. 

Considerable attention has been generated in the commercial sector on blends and composites consisting of synthetic polymers and natural degradable materials. These include starch-polyethylene and starch-ethylene-acrylic acid copolymers. Other natural polymers have also been considered.Until the main concern is addressed that the polyalkene is actually degraded, instead of the specimen having physically disintegrated, this remains a questionable approach. 

Pure polymeric acrylonitrile is not an interesting fiber and it is virtually undyeable. In order to make fibers of commercial iaterest acrylonitrile is copolymerized with other monomers such as methacrylic acid, methyl methacrylate, vinyl compounds, etc, to improve mechanical, stmctural, and dyeing properties. Eibers based on at least 85% of acrylonitrile monomer are termed acryHc fibers those containing between 35—85% acrylonitrile monomer, modacryhc fibers. The two types are in general dyed the same, although the type and number of dye sites generated by the fiber manufacturing process have an influence (see Eibers, acrylic). 

Asymmetric Dieh-Alder Reactions. The commercial availability of either enantiomer of camphorsulfonic acid has made it quite useful in asymmetric Diels-Alder reactions. Reaction of the sultone (generated from CS A) with Lithium Diisopropylamide followed by esterification and (3-elimination yields the crystalline acrylate (eq 14). The Lewis acid-catalyzed [4 + 2] cycloaddition of 1,3-dienes with this acrylate affords the corresponding scalemic adduct which can be reduced with Lithium Aluminum Hydride to yield an enantiomerically pure alcohol (eq 15). ... 

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