Alkyl acrylates, lower

Additives acting on the pour point also modify the crystal size and, in addition, decrease the cohesive forces between crystals, allowing flow at lower temperatures. These additives are also copolymers containing vinyl esters, alkyl acrylates, or alkyl fumarates. In addition, formulations containing surfactants, such as the amides or fatty acid salts and long-chain dialkyl-amines, have an effect both on the cold filter plugging point and the pour point. 

Acryhc esters may be saponified, converted to other esters (particularly of higher alcohols by acid catalyzed alcohol interchange), or converted to amides by aminolysis. Transesterification is comphcated by the azeotropic behavior of lower acrylates and alcohols but is useful in preparation of higher alkyl acrylates. 

Pure dry reactants are needed to prevent catalyst deactivation effective inhibitor systems are also desirable as weU as high reaction rates, since many of the specialty monomers are less stable than the lower alkyl acrylates. The alcohol—ester azeotrope (8) should be removed rapidly from the reaction mixture and an efficient column used to minimize reactant loss to the distillate. After the reaction is completed, the catalyst may be removed and the mixture distilled to obtain the ester. The method is particularly useful for the preparation of functional monomers which caimot be prepared by direct esterification. 

About 60-99 parts of one or more alkyl acrylate monomer. This can also include lower levels of one or more methacrylate monomer. 

Both methyl acrylate and butyl acrylate have been used to prepare vinylidene chloride copolymers with sufficient stability to permit thermal processing. The presence of alkyl acrylate units in the polymer mainchain limits the size of vinylidene chloride sequences and thus the propagation of degradative dehydrochlorination. More importantly it lowers the melt... 

Classic anionic polymerization must be conducted at too low temperature for commercial feasibility. Anionic polymerization of hindered acrylates and methacrylates with stable large counterions works at temperatures close to those required for condenser cooling. The anionic polymerization of lower alkyl acrylates and methacrylates is still a problem. 

The present paper is devoted to the investigation of emulsion polymerization of lower alkyl acrylates in... 

Qnulsion polymerization of lower alkyl acrylates was studied in terms of Interfacial phenomena. Adsorption of emulsifier depending on its nature reduces during... 

One difficulty associated with polymer-based gene therapy is that delivery efficiency is generally low, due to redirection of the polymer complexes to and enzymatic hydrolysis of the DNA in the lysosome, rather than release of DNA from the endosome (see Figure 2). A strategy to circumvent this is to include polymers that disrupt the endosomal membrane. This is achieved if they are active i.e. protonated) at pH 6.5 or below, but inactive (deprotonated) at pH 7.4, since the endosomal pH is around one unit lower than the cytoplasm. Hoffman, Tirrell and co-workers have developed synthetic polymers such as poly(alkyl acrylic acid)s and poly(acrylate-co-acrylic acid)s that show en-... 

Oxidation of waste plastics, such as polyethylene, polypropylene, polystyrene, poly (alkyl acrylates), and nylon 6,6, with NO/O2 for 16 h at 170°C, led to mixtures of carboxylic acids, for which uses would have to be developed if this method was applied to large volumes of waste plastics.180 Hydrogenation of polyethylene at 150C>C for 10 h over a sil-ica/alumina-supported zirconium hydride catalysts gave a 100% conversion to saturated oligomers.181 Polypropylene gave a 40% conversion to lower alkanes at 190°C for 15 h. It is not clear what use these materials would have, other than serving as a feedstock for a petroleum refinery. 

Polymers of lower n-alkyl acrylates are used in plastics to only a limited extent. Ethyl and butyl acrylates are, however, major components of acrylic elastomers. The polymers are usually formed by free-radical emulsion polymerization. Because acrylate esters are sensitive to hydrolysis under basic conditions, the polymerizations are usually conducted at neutral or acidic pH. The acrylic rubbers, like other elastomers, must be crosslinked or vulcanized to obtain optimum properties. Crosslinking can be accomplished by reactions with peroxides through abstractions of tertiary hydrogens by free radicals ... 

The lower n-alkyl derivatives (up to %-butyl reported) have not afforded crystalline polymers with anionic coordinated catalysts, while the branched derivatives have, such as iso-, sec-, and tert-butyl acrylate. Nevertheless, the poly(w-alkyl acrylates) prepared with a heterogeneous SrZnEt4 catalyst are stereoregular. For example, hydrolysis of amorphous poly (methyl acrylate) gives crystalline polyacrylic acid (Makimoto et al., 1961). 

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