Ethylene-acrylate copolymerization

Polymer Composition. Ethylene—acrylic elastomer terpolymers ate manufactured by the addition copolymerization of ethylene [74-85-1] and methyl acrylate [96-33-3] in the presence of a small amount of an alkenoic acid to provide sites for cross-linking with diamines (4). 

We can incorporate short chain branches into polymers by copolymerizing two or more comonomers. When we apply this method to addition copolymers, the branch is derived from a monomer that contains a terminal vinyl group that can be incorporated into the growing chain. The most common family of this type is the linear low density polyethylenes, which incorporate 1-butene, 1-hexene, or 1-octene to yield ethyl, butyl, or hexyl branches, respectively. Other common examples include ethylene-vinyl acetate and ethylene-acrylic acid copolymers. Figure 5.10 shows examples of these branches. 

Scheme 2 Proposed mechanism for ethylene/methyl acrylate copolymerization...

The resulting complexes can be effectively employed as single component catalysts to homopolymerize ethylene or copolymerize ethylene with acrylates [50, 51] and a variety of other polar monomers including vinyl ethers, [51,52] vinyl fluoride [53], iV-vinyl-2-pyrrolidinone, and AMsopropylacrylamide [54], In fact, the resulting catalysts are so robust that they can be used as single component catalysts in aqueous emulsion homo-polymerization of ethylene and copolymerization of ethylene with norbomenes and acylates [55]. 

Scheme 10 Activity reduction in ethylene-methyl acrylate copolymerizations due to the formation of stable chelate 1.30...

Ethylene-1-butene copolymers, 20 180 Ethylene-1-olefin copolymerization, 26 525 Ethylene-acrylic elastomers, 10 696-703 commercial forms of, 10 697-698 dynamic mechanical properties of,... 

Emulsion polymerization was first employed during World War II for producing synthetic rubbers from 1,3-butadiene and styrene. This was the start of the synthetic rubber industry in the United States. It was a dramatic development because the Japanese naval forces threatened access to the southeast Asian natural-rubber (NR) sources, which were necessary for the war effort. Synthetic mbber has advanced significantly from the first days of balloon tires, which had a useful life of 5000 mi to present-day tires, which are good for 40,000 mi or more. Emulsion polymerization is presently the predominant process for the commercial polymerizations of vinyl acetate, chloroprene, various acrylate copolymerizations, and copolymerizations of butadiene with styrene and acrylonitrile. It is also used for methacrylates, vinyl chloride, acrylamide, and some fluorinated ethylenes. 

MOLECULAR DYNAMICS IN THE STUDIES OF THE ETHYLENE - METHYL ACRYLATE COPOLYMERIZATION... 

Figure 4-22. Mechanism of ethylene-methyl acrylate copolymerization monomer insertion...

Michalak A, Ziegler T, DFT Studies on the Copolymerization of a-Olefins with Polar Monomers Ethylene-Methyl Acrylate Copolymerization Catalyzed by a Pd-based Diimine Catalyst, J Am Chem Soc, 123, 12266-12278 (2001)... 

More industrial polyethylene copolymers were modeled using the same method of ADMET polymerization followed by hydrogenation using catalyst residue. Copolymers of ethylene-styrene, ethylene-vinyl chloride, and ethylene-acrylate were prepared to examine the effect of incorporation of available vinyl monomer feed stocks into polyethylene [81]. Previously prepared ADMET model copolymers include ethylene-co-carbon monoxide, ethylene-co-carbon dioxide, and ethylene-co-vinyl alcohol [82,83]. In most cases,these copolymers are unattainable by traditional chain polymerization chemistry, but a recent report has revealed a highly active Ni catalyst that can successfully copolymerize ethylene with some functionalized monomers [84]. Although catalyst advances are proving more and more useful in novel polymer synthesis, poor structure control and reactivity ratio considerations are still problematic in chain polymerization chemistry. 

Vinyl acetate is relatively inexpensive and is readily copolymerized with vinyl chloride, ethylene, acrylates and methacrylates. The monomer is a colourless, flammable liquid with an initial pleasant odour, which on exposure becomes irritating. One of the major disadvantages of vinyl acetate-based copolymers is their poor hydrolytic and UV stability. This was shown to improve when copolymerized with vinyl esters of versatic acid [18]. Copolymers of vinyl acetate with the vinyl esters of versatic acid have been used in Europe for the last quarter-century. In the US similar monomers were introduced in the past five years, two of which are illustrated in Table 6.1, namely, vinyl pivalate and vinyl neo-decanoate. More details of the copolymerization of these monomers with vinyl acetate is given in Chapter 16. 

Ethylene Acrylic Acid Copolymer Specialty thermoplastic created by high-pressure copolymerization of ethylene (E), methacrylic acid (MAA), or acrylic acid (AA). Also called EAA. 

Different types of water-based emulsions are used in EPI adhesives. The most common are poly(vinyl acetate) (PVAc) emulsion, ethylene vinyl acetate (EVAc) emulsion, vinyl acetate-acrylate copolymerized (VAAC) emulsion, acrylic-styrene (AcSt) emulsion or styrene-butadiene rubber (SBR) latex or modified versions of these emulsion types [1, 8, 9], It has also been reported that tri- or ter-polymer emulsions like vinyl acetate-butyl acrylate-hydroxypropyl methacrylate or emulsions with different combinations of block copolymers can be used [4], Emulsion polymers containing cross-linking functional groups are especially well suited [4,6, 9]. The choice of emulsion(s) will, to a large extent, influence the adhesive properties such as setting time, bond quality, heat resistance, and moisture resistance. EPI adhesive systems are, however, very complex and the total composition (including the choice of cross-linker) and the interaction between the different components will determine the properties of the adhesive. Due to this it is difficult to describe in detail the effect of choosing one type of emulsion over the other. 

The complexity of intramolecular transfer (SCB) mechanisms in ethylene/acrylate [42], styrene/acrylate [43] and methacrylate/acrylate [40] copolymer systems has also been studied, as has the combination of scission and copolymerization [40, 44]. All possible reaction pathways must be carefully considered, building from an understanding of the secondary mechanisms gained from homopolymerization studies. 

Ethylene is copolymerized with many nonolefinic monomers, particularly acrylic acid variants and vinyl acetate, with EVA polymers being the most commercially significant. All of the copolymers discussed in this section necessarily involve disruption of the regular, crystallizable PE homopolymer and as such feature reduced yield stresses and moduli, with improved low-temperature flexibihty. 

Copolymerization of N-vinylpyrrolidone with vinyl chloride [59]. Copolymerization of N-vinylpyrrolidone with vinyl acetate [59]. Copolymerization of A -vinylpyrrolidone with ethylene [102]. Copolymerization of A -vinylpyrrolidone with acrylates, methacrylates, or mixed acrylic monomers, initiated by / r/-butyl perbenzoate [103]. 

Ziegler-Natta, Phillips, and metallocene catalysts are extensively used to produce polyolefins by catalytic polymerization. These catalysts allow a good control of polymer microstmctiue and large productivities, but they are based on early transition metals (Ti, Zr, Cr, and V), which are oxophilic, and hence sensitive to water. Therefore, they cannot be used in aqueous systems although some relative success has been recently repotted in the polymerization of styrene with metallocene catalysts. Late transition metals (Rrr, Co, Rh, Ni, and Pd) are much less oxophilic, and hence they may be used in water systems. In the past 30 years, a great deal of work has been done to develop late transition metal catalyst to polymerize ethylene and copolymerize it with acrylates in both solvent and aqueous phases. ° Tfre neutral nickel complexes of [P,0]... 

More recently, monometallic palladium catalysts " containing a sulfonated phosphine ligand have been developed that are able to homopolymerize ethylene and copolymerize ethylene with acrylates and other polar monomers in both solution and aqueous phase. In solution, the activity... 

Vinyl Acetate-Based Copolymers and Derived Polymers. Vinyl acetate units transmit their intrinsic adhesivity to all VA-containing polymers. Thus, vinyl acetate is copolymerized with ethylene, acrylic monomers, and so on. Its reaction behavior can be predicted through parameters Q = 0.026 and e = 0.22 (see Section 8.5.11). 

Currently ethylene-acrylate and ethylene-vinyl acetate copolymers are commercially produced by radical polymerizations in high-pressure reactors. In recent times much effort has gone into developing singlesite catalysts for the copolymerization of ethylene and polar vinyl monomers. 

Fig. 2. Relationship between relative rate and monomer composition in the copolymerization of DAP with vinyl monomers A, styrene or methyl methacrylate B, methyl acrylate or acrylonitrile C, vinyl chloride D, vinyl acetate, and E, ethylene (41).

The simplest monomer, ethylenesulfonic acid, is made by elimination from sodium hydroxyethyl sulfonate and polyphosphoric acid. Ethylenesulfonic acid is readily polymerized alone or can be incorporated as a copolymer using such monomers as acrylamide, aHyl acrylamide, sodium acrylate, acrylonitrile, methylacrylic acid, and vinyl acetate (222). Styrene and isobutene fail to copolymerize with ethylene sulfonic acid. 

Although they lack commercial importance, many other poly(vinyl acetal)s have been synthesized. These include acetals made from vinyl acetate copolymerized with ethylene (43—46), propjiene (47), isobutjiene (47), acrylonitrile (48), acrolein (49), acrylates (50,47), aHyl ether (51), divinyl ether (52), maleates (53,54), vinyl chloride (55), diaHyl phthalate (56), and starch (graft copolymer) (47). 

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