Alkyl esters of acrylic acids

Tphis paper is concerned with the effect of ionizing radiation on the physical and mechanical properties of copolymers of ethylene with alkyl acrylates, such as ethyl acrylate, butyl acrylate, and 2-ethvlhexyl acrylate (J, 2, 3). These polymers are made by the free radical copolymerization of ethylene under high pressure with alkyl esters of acrylic acid (9). They are more flexible than polyethylene and because of the polar nature of the comonomer, they are more compatible with fillers and with other polymers than is polyethylene. 

Acrylics. There are two principal classes of acrylic sealants latex acrylics and solvent-release actylics. High molecular weight latex acrylic polymers are prepared by emulsion polymerization of alkyl esters of acrylic acid, The emulsion polymers are compounded inlo sealants by adding fillers, plasticizers, freeze-thaw stabilizers, thickeners, and adhesion promoters. As is true of the silicone lalex sealants, die acrylic latex sealants are easy to apply and clean with water. 

Ventura, K., Prihoda, P. and Churacek, J. (1995) Aplication of solid sorbents to the trace analysis of alkyl esters of acrylic acid in air. Journal of Chromatography A, 710,... 

It should be noted that tBA is currently the only acrylate monomer that undergoes living anionic polymerization to afford polymers with up to a few 10 gmor or higher values rmder suitable conditions. This means that it is necessary to synthesize functional terf-alkyl esters of acrylic acid, as shown in Figure 31, in order to achieve the living anionic polymerization of protected acrylate... 

Alkyl and 1-aralkyl-5,6-dihydrouracils (LXXIX), prepared by condensation of A -(2-carbamoylalkyl)aralkylamines with urea or by treating a suitable primary amine with an ester of acrylic acid followed by cyanic acid, are CNS depressants and anticonvulsants [639, 640], as well as anti-inflammatory agents [641]. Such compounds are to be compared with the corresponding barbituric acid derivatives in which not more than one hydrogen in the 5-position is substituted, and also with barbiturates in which the 5,5-substituents are similar to the R and groups of the 5,6-positions here. 

These materials are the reaction product of a primary amine and either acrylic acid, an ester of acrylic acid such as methyl acrylate, ethyl acrylate or crotonic acid. Either 1 or 2 mol of acrylate is used. If 1 mol is added, an N-alkyl (3-alanine is produced (Figure 6.6) and if 2 mol of acrylate per mole of amine is used, the corresponding carboxyethyl (3 -alanine derivative is produced (Figure 6.7). 

Natta, Farina, and Donati (47) have prepared diisotactic polymers from alkyl esters of sorbic acid and /5-styryl acrylic acids by anionic initiation with optically pure 2-methyl butyllithium. The polymers were optically active. 

One class of such materials is the fluorinated alkyl esters of acrylic and methacrylic acid, a number of which have been prepared [1]. One of these esters, poly(l,l-dihydropentadecafluoro-octyl methacrylate), has a 11 dynes per cm.—less than Teflon TFE or even FEP [4]. Such materials, and others within the general class of unsaturated, appropriately fluorinated, polyesters warrant investigation for use either as thermoplastic hot-melt adhesives, or for cross linking in situ to form rigid thermoset adhesives. The saturated, appropriately fluorinated polyesters also warrant investigation as thermoplastic hot-melt adhesives. 

Copolymers containing allyl methacrylate have found application as an additive to other resin to enhance the properties of the system. For example, in one patent disclosure, an aqueous emulsion polymer was formed in water using 0.03 gm of sodium carbonate, 50 gm of methyl methacrylate, 2.0 gm of ethyl acrylate, and 0.1 gm of allyl methacrylate, and 0.40 gm of the sodium salt of an allyl Ci3-alkyl ester of sulfosuccinic acid. The polymerization was initiated with sodium persulfate and heated at 83°C for 1 hr. To this latex, 40 gm of butyl acrylate, 10 gm of styrene, 1.0 gm of allyl methacrylate, and another 0.40 gm of the above surfactant were added while polymerization continued. In a third... 

Emulsion polymers derived from acrylic monomers are easily the most composi-tionally diverse and versatile family of the commercially important broad classes of emulsion polymers. By acrylic we mean polymers of mcHiomeric alkyl esters of acrylic and methacrylic acid, but also include, usually as lesser components of the polymers, the free acids themselves and derivatives such as their amides, nitriles and aldehydes, as well as amides and esters bearing functional groups on the side chain, such as hydroxyl. 

Acrylo-type compoimds, such as acrylic acid, acrylonitrile and acrolein can be present in polyacrylamides. Their unsaturated characteristics could cause them to interfere with the acrylamide analysis. Acrylic acid is electroreducible, but its anionic form, acrylate is not. A polarogram of acrylic acid and acrylamide in an 80 20 (v/v) methanol/water solution with tetra-/i-butylammonium chloride as the supporting electrolyte showed that the reduction of the associated acid occurs at ca. - 1.7 V vs SCE, 0.3 V more positive than the acrylamide reduction. The reduction peak of acrylic acid is easily resolved from acrylamide. Esters of acrylic acid are electroreducible and some, such as the alkyl esters (eg. ethyl acrylate) reduce in the same potential region as acrylamide and do constitute an interference. Acrylonitrile is also electroreducible at the same potential as acrylamide. However, the high volatility of acrylonitrile allows it to be readily purged from the analyte solution. The detection limit of acrylamide monomer by this technique is less than 1 ppm. 

Polyacrylics. Polyacrylic adhesives and sealants are formulated from functional acrylic monomers, which achieve excellent bonding upon polymerization.Alkyl esters of acrylic or methacrylic acids up to 80,000 molecular weight constitute the main bonds of acrylic sealants. 

The earliest study describing vulcanised polymers of esters of acryUc acid was carried out in Germany by Rohm (2) before World War I. The first commercial acryUc elastomers were produced in the United States in the 1940s (3—5). They were homopolymers and copolymers of ethyl acrylate and other alkyl acrylates, with a preference for poly(ethyl acrylate) [9003-32-17, due to its superior balance of properties. The main drawback of these products was the vulcanisation. The fully saturated chemical stmcture of the polymeric backbone in fact is inactive toward the classical accelerators and curing systems. As a consequence they requited the use of aggressive and not versatile compounds such as strong bases, eg, sodium metasiUcate pentahydrate. To overcome this limitation, monomers containing a reactive moiety were incorporated in the polymer backbone by copolymerisation with the usual alkyl acrylates. 

Esters. Most acrylic acid is used in the form of its methyl, ethyl, and butyl esters. Specialty monomeric esters with a hydroxyl, amino, or other functional group are used to provide adhesion, latent cross-linking capability, or different solubility characteristics. The principal routes to esters are direct esterification with alcohols in the presence of a strong acid catalyst such as sulfuric acid, a soluble sulfonic acid, or sulfonic acid resins addition to alkylene oxides to give hydroxyalkyl acrylic esters and addition to the double bond of olefins in the presence of strong acid catalyst (19,20) to give ethyl or secondary alkyl acrylates. 

Acrolein, acrylamide, hydroxy alkyl acrylates, and other functional derivatives can be more hazardous from a health standpoint than acrylic acid and its simple alkyl esters. Furthermore, some derivatives, such as the allyl 2-cliloroacrylates, are powerflil vesicants and can cause serious eye injuries. Thus, although the hazards of acrylic acid and the normal alkyl acrylates are moderate and they can be handled safely with ordinary care to industrial hygiene, this should not be assumed to be the case for compounds with chemically different functional groups (see Industrial hygiene Plant safety Toxicology). 

In ASA terpolymer acrylic acid brings more flexibility and the material has very good mechanical properties and weather resistance. For these reasons ASA is extensively used in automotive industry and in the fabrication of various appliances. Even more frequently than acrylic acid itself, various acrylates are used in copolymers. Among these can be mentioned the copolymers of acrylic acid esters with methacrylic acid esters such as poly(methyl methacrylate-co-methyl acrylate), poly(methyl methacrylate-co-ethyl acrylate), poly(methyl methacrylate-co-butyl acrylate), poly(ethyl methacrylate-co-ethyl acrylate), poly(acrylonitrile-co-methyl acrylate), poly(alkyl acrylate-co-methyl methacrylates), and poly(alkyl acrylate-co-hydroxyethyl methacrylates) where alkyl can be methyl, ethyl, butyl, etc. Some literature information regarding thermal decomposition of copolymers including acrylic acid and acrylic acid esters is given in Table 6.7.8 [6],... 

Direct, acid catalyzed esterification of acrylic acid is the main route for the manufacture of higher alkyl esters. The most important higher alkyl acrylate is 2-ethylhexyl acrylate prepared from the available oxo alcohol 2-ethyl-1-hexanol (see Alcohols, higher aliphatic). The most common catalysts are sulfuric or toluenesulfonic acid and sulfonic acid functional cation-exchange resins. Solvents are used as entraining agents for the removal of water of reaction. The product is washed with base to remove unreacted acrylic acid and catalyst and then purified by distillation. The esters are obtained in 80—90% yield and in excellent purity. 

Poly(2-alkyl oxazoline)s having methacrylate or acrylate end groups were prepared by two methods [182]. a) Living polyoxazoline chains, prepared using methyl p-toluene sulphonate as initiator, were end-capped by reaction with metal salts or tetraalkylammonium salts of acrylic or methacrylic acid or a trialky-lammonium salt or trimethylsilyl ester of methacrylic acid (functional termination). b) The living polymers were terminated with water in the presence of Na2C03 to provide hydroxyl-terminated chains. Subsequent acylation with acry-loyl or methacryloyl chloride in the presence of triethylamine led to the formation of the macromonomers. The procedures are outlined in the following Scheme 51. 

Reetz, M. T., and R. Ostarek, Polymerization of Acrylic Acid Esters Initiated by Tetrabutylammonium Alkyl and Aryl Thiolates, ... 

All vinyl polymers are addition polymers. To differentiate the, the homopolymers have been classified by the substituents attached to one carbon atom of the double bone. If the substituent is hydrogen, alkyl or aryl, the homopolymers are listed under polyolefins. Olefin homopolymers with other substituents are described under polyvinyl compounds, except where the substituent is a nitrile, a carboxylic acid, or a carboxylic acid ester or amide. The monomers in the latter cases being derivatives of acrylic acid, the derived polymers are listed under acrylics. Under olefin copolymers are listed products which are produced by copolymerization of two or more monomers. 

Synonyms AA/AM Acrylamide/acrylic acid copolymer Acrylic acid/ acrylamide copolymer Propenamide, polymer with propenoic acid, butenoic acid, and/or alkyl propenoates Definition Polymer of acrylamide and one or more monomers of acrylic acid, methacrylic acid or one of their simple esters Properties Nonionic... 

Solvents influence the rate of free-radical homopolymerization of acrylic acid and its copolymerization with other monomers. Hydrogen-bonding solvents slow down the reaction rates. Due to the electron-withdrawing nature of the ester groups, acrylic and methacrylic ester polymerize by anionic but not by cationic mechanisms. Lithium alkyls are very effective initiators of a-methyl methacrylate polymerization yielding stereospecific polymers.Isotactic poly(methyl methacrylate) forms in hydrocarbon solvents. Block copolymers of isotactic and syndiotactic poly(methyl methacrylate) form in solvents of medium polarity. Syndiotactic polymers form in polar solvents, like ethylene glycol dimethyl ether, or pyridine. This solvent influence is related to Lewis basicity in the following order ... 

Using this procedure, the recovery of alkyl iodides is greater than 95% for polymers containing between 10 and 90% of the methyl, ethyl, and butyl esters of acrylic and methacrylic acid. In addition, the use of isopropylbenzene as the trapping solvent allows the determination of all to C4 alkyl iodides. 

---