Ethyl acrylate properties

Historically, the development of the acrylates proceeded slowly they first received serious attention from Otto Rohm. AcryUc acid (propenoic acid) was first prepared by the air oxidation of acrolein in 1843 (1,2). Methyl and ethyl acrylate were prepared in 1873, but were not observed to polymerize at that time (3). In 1880 poly(methyl acrylate) was reported by G. W. A. Kahlbaum, who noted that on dry distillation up to 320°C the polymer did not depolymerize (4). Rohm observed the remarkable properties of acryUc polymers while preparing for his doctoral dissertation in 1901 however, a quarter of a century elapsed before he was able to translate his observations into commercial reaUty. He obtained a U.S. patent on the sulfur vulcanization of acrylates in 1912 (5). Based on the continuing work in Rohm s laboratory, the first limited production of acrylates began in 1927 by the Rohm and Haas Company in Darmstadt, Germany (6). Use of this class of compounds has grown from that time to a total U.S. consumption in 1989 of approximately 400,000 metric tons. Total worldwide consumption is probably twice that. 

Mechanical and Thermal Properties. The first member of the acrylate series, poly(methyl acrylate), has fltde or no tack at room temperature it is a tough, mbbery, and moderately hard polymer. Poly(ethyl acrylate) is more mbberflke, considerably softer, and more extensible. Poly(butyl acrylate) is softer stiU, and much tackier. This information is quantitatively summarized in Table 2 (41). In the alkyl acrylate series, the softness increases through n-octy acrylate. As the chain length is increased beyond n-octy side-chain crystallization occurs and the materials become brittle (42) poly( -hexadecyl acrylate) is hard and waxlike at room temperature but is soft and tacky above its softening point. 

Sulfonation has been used to change some characteristics of blends. Poly(2,6-diphenyl-l,4-phenylene oxide) and polystyrene are immiscible. However, when the polymers were functionalized by sulfonation, even though they remained immiscible when blended, the functionalization increased interfacial interactions and resulted in improved properties (65). In the case of DMPPO and poly(ethyl acrylate) the originally immiscible blends showed increased miscibility with sulfonation (66). 

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. 

Fig. 3. Elastomer properties as a function of monomer composition, butyl acrylate (BA), ethyl acrylate (FA), and methoxyethyl acrylate (MEA). (a), (—) glass-transition temperature (------------) swelling in ASTM No. 3 oil (b) (-) residual elongation at break, %, after heat aging.

In order to improve the physical properties of HDPE and LDPE, copolymers of ethylene and small amounts of other monomers such as higher olefins, ethyl acrylate, maleic anhydride, vinyl acetate, or acryUc acid are added to the polyethylene. Eor example, linear low density polyethylene (LLDPE), although linear, has a significant number of branches introduced by using comonomers such as 1-butene or 1-octene. The linearity provides strength, whereas branching provides toughness. 

Property lonomer Ethlene-vinyl acetate Ethylene-ethyl acrylate Units... 

Improvement in the solvent and oil resistance of rubbers can be achieved via grafting of acrylonitrile onto rubber [140-142] and rubber blends [143]. The careful control of the degree of grafting allows vulcanized rubber with high-mechanical properties compared with ungrafted vulcanized rubber to be obtained. Also, acid resistance [144] and resistance to microbiological attack [145,146] was improved for cellulose grafted with acrylonitrile, and increases in base resistance were also noted for MMA and a mixture of MMA and ethyl acrylate [13],... 

The carboxylated polymers [476,499] include acrylic, methacrylic or maleic acid polymers (all obviously anionic in character) applied mainly from aqueous emulsion and particularly in combination with crease-resist or durable press resins. This type of chemistry has already been discussed in section 10.8.2. A particularly common example is the copolymer of acrylic acid with ethyl acrylate (10.247). In general the best balance of properties is obtained with 75-85% ethyl acrylate (y) and 25-15% acrylic acid (x), with an average chain length of about 1300 (x + y) units 65-85% ethyl acrylate with 35-15% methacrylic acid is also suitable. When the content of the acidic comonomer increases above about 30% the durability to washing tends to decrease, whilst longer chains tend to give a stiffer handle [499]. 

The most stable resin for many of our purposes has proven to be a copolymer of ethyl methacrylate and methyl acrylate. This comes as little surprise the Rohm and Haas Company has for years sold a durable resin based on these two monomers, Acryloid B-72 (6,28). We have also prepared polymers of similar physical properties based on methyl methacrylate and ethyl acrylate and have found that their behavior is practically the same - the methyl and ethyl groups apparently do not become seriously involved in crosslinking. As reported elsewhere( 23), rather than crosslink, Acryloid B-72 tends to chain break under visible and near-ultraviolet radiation, although at a very slow rate. Polyvinylacetate is another polymer used in the care of museum objects that tends more to chain break than crosslink under these conditions(23), but it is not our purpose to discuss its properties at this time. 

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. 

Properties of Crosslinked Films. Our purpose was to determine which commercially useful property improvements result from radiation crosslinking of ethylene-ethyl acrylate copolymers. Table III illustrates... 

Table III. Physical Properties at 25°C. of Blown Film (1.5 mils) Made from 10% Ethyl Acrylate Copolymer"...

Rubberlike Properties. Figure 2 depicts the changes in the 13.7-micron infrared crystallinity band with increasing ethyl acrylate content. At 25-30% acrylate content in the copolymer, this band disappears, indicating that this polymer is essentially amorphous. This fact, plus the absence of carbon-carbon unsaturation, good filler compatibility, and... 

Morphological structures and properties of a series of poly(ethyl acrylate)/clay nanocomposites prepared by the two distinctively different techniques of in situ ATRP and solution blending were studied by Datta et al. [79]. Tailor-made PNCs with predictable molecular weights and narrow polydispersity indices were prepared at different clay loadings. WAXD and studies revealed that the in situ approach is the better option because it provided an exfoliated morphology. By contrast, conventional solution blending led only to interlayer expansion of the clay gallery. 

Acrylates, for example, contain an a, 3-unsaturated carbonyl system and as such undergo Michael addition reactions. This is believed to be the basis of the carcinogenic properties of acrylates [21]. Incorporation of a methyl (-CH3) group on the a-carbon (to provide a methacrylate) decreases the electrophilicity (i.e., reactivity) of the (3-carbon [40], hence methacrylates do not undergo 1,4-Michael addition reactions as readily. Methacrylates often have commercial efficacy similar to that of acrylates in many applications, but are less likely to cause cancer because they are less reactive. This point can be demonstrated by comparing methyl methacrylate (6), which does not cause cancer in experimental animals [41], with ethyl acrylate (7), which causes cancer in experimental animals in assays similar to those used to test 6 [42]. 

Among the polyesters that are used for PVC, the copolymers of butadiene with ethyl fumarates and ethyl acrylates deserve mention. They have been produced by Badische Anilin-und Sodafabrik (BASF) under the commercial name Palamoll. Palamoll I consists of 75% diethyl fumarate and 25% butadiene Palamoll II contains equal parts of butadiene and ethyl acrylate. In combination with the same amount of liquid plasticizers (such as DOP), films with cold resistance down to — 60°C. can be produced. These products are especially important for cable insulation because of their good dielectric properties. The Palamoll products are produced by emulsion polymerization and can be directly combined with emulsions of PVC. 

In liquid phase reactions, the importance of the swelling properties and the related sorption capacities for the catalytic activity of ion exchangers was demonstrated. The rate coefficient of 1-butanol—acetic acid esterification [431] decreased with the degree of crosslinking in the same manner as did the water sorption capacity and the solvation coefficient of 1-butanol. A similar effect was found for the transesterification of ethyl acrylate with 1-butanol [404]. 

Sperling, L. H., and A. V. Tobolsky Thermoelastic properties of poly (dimethyl siloxane) and poly (ethyl acrylate) as a function of temperature. J. MakromoL Sci. 1, 799 (1966). 

These are made in emulsion or suspension systems involving the copolymerization of ethyl acrylate with the acrylate esters of higher-molecular-weight alcohols. These materials have excellent sulvenl-resi.stunl properties and stability at elevated temperatures. A major use is fur automatic-transmission gaskets lor automobiles. 

Table X. Effects of Degree of Polymerization of the Irradiated Cellulose and Extent of Grafting on the Elastic Recovery Properties of Fibrous Cellulose—Poly (ethyl acrylate) at 25°C...

The elastomers exhibited rubber-like behavior. From an examination of electron photomicrographs of cross sections of the elastomers, the fibrillar structure of the cellulose fibers apparently formed a network, and poly (ethyl acrylate) was distributed uniformly among the fibrils. The rigid crystalline regions of the cellulose fibers apparently stabilized the amorphous, grafted poly (ethyl acrylate) to determine the mechanical properties of the elastomers (43, 44). For example, typical elastic recovery properties for these elastomers are shown in Table X. 

MA/EA/VA) (polymer is approx. 80% hydrolyzed maleic anhydride, 10% ethyl acrylate, 10% vinyl acrylate) has been available for many years and exhibits properties similar to those of PMA. It cannot operate at the same extremes of service, but is of lower cost and competes well with other technologies. It has better general dispersion properties than many polyacrylates and is less sensitive to soluble iron. It can often replace polyacrylates as a phosphonate activity enhancer. 

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