Acrylic and Methacrylic Esters

Methyl, ethyl, butyl, 2-ethylhexyl, isooctyl, 2-hydroxyethyl, etc., acry- 

Acrylic esters-MA monomer mixtures are generally polymerized in solution, with BPO or azobisisobutyronitrile (AIBN) initiators. The highest rates of copolymerization are observed in heterogeneous phase systems, where the difference in the solubility parameter of the solvent and the copolymer is 1.4 Hildebrand. The copolymerization rate constant for the methyl acry-late-MA pair, at 25°C, has been estimated as 588 liters mol For 

Photochemical (UV) initiated copolymerizations of MA with acrylates and methacrylates progresses well in benzene or dioxane, even without added photoinitiators.With UV initiation, the molecular weight of the copolymers decreased with an increase of MA in the comonomer feed. Also, the rate of copolymerization increased but the molecular weights decreased as the concentration of dioxane in the comonomer solution increased. As expected, mercaptans are useful chain regulators to obtain low-molecular-weight materials. 

The glass transition temperature (Tg) of the methyl acrylate-MA copolymers have been obtained for materials with 8.0-43.7 mol % anhydride. Over this range, Tg varied from 28.3 to 119.6°C. The results were discussed 

The patent literature claims that methyl, ethyl, and butyl acrylate-MA copolymers are useful in a variety of coatings, such as enteric. 

---

Table 9. Common Functional Monomers for Copolymerization with Acrylic and Methacrylic Esters...

The largest volume commercial derivatives of 1-butanol are -butyl acrylate [141-32-2] and methacrylate [97-88-1] (10). These are used principally ia emulsion polymers for latex paints, ia textile appHcations and ia impact modifiers for rigid poly(vinyl chloride). The consumption of / -butanol ia the United States for acrylate and methacrylate esters is expected to rise to 182,000—186,000 t by 1993 (10). 

Figure 15.12. Brittle points of n-alkyl acryl acrylate and methacrylate ester polymers. (After Rehberg and Fisher, copyright 1948 by The American Chemical Society and reprinted by permission of the...

For less polar monomers, the most extensively studied homopolymerizations are vinyl esters (e.g. VAc), acrylate and methacrylate esters and S. Most of these studies have focused wholly on the polymerization kinetics and only a few have examined the mierostructures of the polymers formed. Most of the early rate data in this area should be treated with caution because of the difficulties associated in separating effects of solvent on p, k and initiation rate and efficiency. 

B.B. Kine and R.W. Novak, Acrylic and methacrylic ester polymers. In J.I. Kroschwitz (Ed.), Encyclopedia of Polymer Science and Engineering, Wiley, Chichester, 1985, pp. 234-299. 

The preparation of fluorinated alcohols was carried out in multistep routes according to the reported procedures.1012 The synthesis of acrylic and methacrylic esters as shown in Table 11.1 was carried out in a fluorocarbon solvent such as Freon 113 by the reaction of the respective fluorinated alcohol with acryloyl chloride or methacryloyl chloride and an amine acid acceptor such as triethyla-mine with examples shown in Scheme 1. Other attempts to esterify the fluoroalcohols directly with acrylic acid or acrylic anhydride were not successful.11 Product purification by distillation was not feasible because of the temperature required, but purification by percolation of fluorocarbon solutions through neutral alumina resulted in products of good purity identified by TLC, FTIR, and H-, 13C-, and 19F- FTNMRs. 

Close to 2 billion pounds of polymeric products based on acrylic and methacrylic esters are produced annually in the United States, about evenly divided between acrylates and methacrylates. A substantial fraction of the methacrylate products are copolymers. Most of the acrylate products are copolymers. The copolymers contain various combinations of acrylate and/or methacrylate monomers, including combinations of ester and acid monomers. Methyl methacrylate (MMA) is by far the most important methacrylate ester monomer, accounting for 90% of the volume of methacrylic ester monomers. Ethyl and n-butyl acrylates account for about 80% of the total volume of acrylate ester monomers. 

Alkyl derivatives of the alkaline-earth metals have also been used to initiate anionic polymerization. Organomagnesium compounds are considerably less active than organolithiums, as a result of the much less polarized metal-carbon bond. They can only initiate polymerization of monomers more reactive than styrene and 1,3-dienes, such as 2- and 4-vinylpyridines, and acrylic and methacrylic esters. Organostrontium and organobarium compounds, possessing more polar metal-carbon bonds, are able to polymerize styrene and 1,3-dienes as well as the more reactive monomers. 

Polymerizations of acrylic and methacrylic esters are highly exothermic (e.g., A//polymeriZation of ethyl acrylate is 13.8 kcal/mol [2]). Generally, the heats of polymerization of acrylates are greater than those of methacrylates. 

Armstrong et al. have extensively studied the effect of this radiation on grafting butadiene, styrene, vinyl chloride, vinyl esters, acrylic, and methacrylic esters, acrylonitrile and other less common monomers on Nylon 66 fibers. They observed the influence of oxygen, water, methanol, acetic acid, dose of irradiation as well as temperature (160-163). 

Optically active acrylic, chloro-acrylic and methacrylic esters of sec. butyl alcohol, 2-methyl-butyl alcohol, 1.3-dimethyl-butyl alcohol, 1-methyl-benzyl alcohol, bomeol and menthol have been polymerized mostly by radical mechanism (Tables 16, 17, 18). 

Monomers with electron withdrawing groups are polymerized by phosphines (acrylic and methacrylic esters, acrolein, methyl vinyl ketone, /J-nitrostyrene, nitro-ethylene, acrylonitrile), whereas the phosphines have no effect on monomers more susceptible to acid catalysts (isobutylene, styrene). 

Monomer Purification. All polymers were prepared from either column purified or distilled monomers. The acrylate and methacrylate esters, styrene, and vinyl nitrile type monomers were purified by passing them through Rohm and Haas Amberlyst exchange resins (salt forms), while the diene monomers were either distilled directly from cylinders and condensed in a dry ice trap or alternatively caustic washed to remove the inhibitor. 

In addition to the above-mentioned monomers, various acrylic and methacrylic esters, methacrylonitrile, itaconic acid, crotonic acid, methyl vinyl ketone, allyl alcohol, allyl amine etc., have been studied by Fischer... 

Storage and Handling of Acrylic and Methacrylic Esters and Acids, CM-17, Rohm and Haas Co., Philadelphia, Pa. 

Latex copolymers including NIBA have found applications in protective coatings, binders for nonwoven fabrics, water and oil repellancy, crease resistance, print pastes, leather finishing, adhesives, paper impregnation, curable thickeners and elastomers. (2B). Comonomers include acrylic and methacrylic esters, acrylo nTtrile, styrene, and occasionally vinyl acetate or vinyl chlorida... 

The experimental difficulties involved with the controlled use of Grignard initiators were recognized early on. The exact nature of the species present in the reaction media is often unclear. In many instances, it is difficult to obtain reproducible kinetic data. The polymerizations are very sensitive to the presence of small concentrations of impurities. Finally, the polymerization of acrylic and methacrylic esters is further complicated by side reactions involving the carbonyl group. Consequently, it is not uncommon for two workers in the same laboratory to prepare different products using the same procedure [9,10]. 

Table 3 Polvmerization of Acrylic and Methacrylic Esters Using Organomagnesium Initiators...

The third type of composition is exemplified acrylate- and methacrylate-ester derivatives of epoxy resins combined with a photoinitiator 1. Epo prepolymers (e. g., glycidyl methacrylate-allyl glycidyl ether copolymers or Ciba ECN 1299) combined with a photosensitive aryldiazonium compound (e.g.,... 

Probably the first polymerizable ultraviolet absorbers for general use were acryloyl or methacryloyl derivatives of the 1-hydroxy group of 2,1-dihydroxybenzophenone (7). Acrylic and methacrylic esters have also been prepared from 2(2-hydroxyphenyl)2H-benzotria-zoles with a phenolic hydroxyl group in the carbocyclic ring of a benzotriazole group (8). 

Acrylic and methacrylic esters Vinylidene esters Derivatives of acrylonitrile... 

The third type of composition is exemplified by acrylate- and methacrylate-ester derivatives of epoxy resins combined with a photoinitiator 1. Epoxy prepolymers (e. g., glycidyl methacrylate-allyl glycidyl ether copolymers or Ciba ECN 1299) combined with a photosensitive aryldiazonium compound (e.g., -nitrobenzenediazonium hexaflourophosphate) (38,39) 2. Epoxy prepolymers (e.g., a diglycidyl ether of disphenol A-(3,4-epoxycyclohexyl)-methyl-3,4-epoxycyclohex-anecarboxylate-alkyl glycidyl ether mixture) combined with a photosensitive aryldiazonium compound (e.g., -chlorobenzenediazonium hexaflourophosphate) and l-methyl-2-pyrrolidone gelation inhibitor (40) ... 

Other widely used substrate types are acrylic and methacrylic esters and other a,/(-unsaturated carboxylic acid derivatives206. Depending on the substitution pattern and reaction conditions 2- or 3-formyl carboxylic acid derivatives are formed with good regioselectivities and medium to good ee values (see Table 7). 

A variety of urethane coating systems has been introduced based on hydroxyl-containing acrylic and methacrylic ester copolymers that contain hydroxyethyl acrylates or methacrylates and that are generally cured with aliphatic di- or polyisocyanates. Depending upon the type and relative amounts, acrylate or other saturated esters, for example, adipate-isophthalic esters, are also used in combination with aliphatic polyisocyanates. 

Both anion and cation hydrocarbon-type exchange membranes (styrene-divinyl-benzene copolymer type) are generally stable in ordinary concentrations of acid solutions (about 40% sulfuric acid, 10% hydrochloric acid, 20% nitric acid, 50% acetic acid) and in alkali solutions such as sodium hydroxide (5%), ammonia (4%), etc.64 However, ion exchange membranes using ethylene glycol dimethacrylate, sulfoethyl methacrylate, and other acrylic and methacrylic esters, are less stable than styrene-divinylbenzene type membranes. 

OTHER COMMENTS used as a chemical intermediate for manufacture of high purity nickel catalyst for manufacture of acrylic and methacrylic esters an effective catalyst in the carbonylation reaction and for the manufacture of tetrahydrofuryl alcohol use in glass plating and continuous nickel coatings on steel and other metals. 

---