Ethylene acrylic acid from

Acrylic acid is an important material for the chemical Industry, either as such or in (he form of acrylates and acrylamides. The Union Oil synthesis of acrylic acid from ethylene is performed at 140-150 C, 77 atm, C2 H4/CO 1 (Otalyst 0.1% PdOj. 0.5% CUCI2 in the presence of lithium acetate and chloride). The solvent is a mixture of acetic acid and acetic anhydride (about 20%) 24. The chemical steps of this Wacker-type catalysis are outlined ... 

These are shown by reaction 4.7.3.2. Oxidative coupling between and CO2 produces a metallalactone intermediate that on /3-hydrogen transfer can produce one of the units of the dinuclear structure 4.57. Manufacture of acrylic acid from ethylene and CO is an atfractive target. However, turning stoichiometric reactions of Ihe type (4.7.3.1) into catalytic ones has not been possible so far. 

The production of acrylic acid from the oxidative carhonylation of ethylene is descrihed in Chapter 7. 

Acetaldehyde also comes as a by-product in the production of vinyl acetate from ethylene and production of acrylic acid from propylene. 

Heterogeneous oxidative processes operate at high temperatures (250-450 6C) and are useful for the synthesis of acrolein and acrylic acid from propylene over bismuth molybdate catalysts, the synthesis of maleic and phthalic anhydrides from the oxidation of benzene (or C4 compounds) and naphthalene (or o-xylene) respectively over vanadium oxide,101 arid the synthesis of ethylene oxide from ethylene over silver catalysts.102... 

There are many synthetic procedures for preparing acrylic acid and its esters. One way, used for a long time, is to make acrylic esters from ethylene oxide ... 

L. Serra, J. Domenech, N.A. Peppas, Drug transport mechanisms and release kinetics from molecularly designed poly(acrylic acid-g-ethylene glycol) hydrogels. Biomaterials, 27,... 

A dinickel(I) compound 17 was made from the reaction between metallacyclic Ni(n) carboxylate ( nickelalactone ) and bis(diphenylphosphino)methane (dppm) (Scheme 10.7) [11]. The Ni(I)-Ni(I) bond length in 17 is 2.563(1) A (Entry 4, Table 10.2), and features three different bridging ligands (dppm, carboxylate, diphenylphosphido). The formation of 17 was proposed to proceed via the mechanism depicted in Scheme 10.8, and is remarkable because it acts as a model for the key step in the formation of acrylic acid from COj and ethylene. 

The product mix of autoclave and tubular reactors are similar in terms of LDPE homopolymers (0.910-0.935 g/cc) and some specialty grades of polyethylene such as ethylene/vinyl acetate copolymers up to about 30 wt% vinyl acetate (VA). However, the autoclave process provides higher levels of vinyl acetate (40 wt%) in ethylene/VA copolymers and additional specialty grades of polyethylene such as ethylene/methyl acrylate, ethylene/acrylic acid and ethylene/n-butyl acrylate. Polyethylene molecular weight can be varied over a wide range with the high-pressure process, with Melt Index values (I ranging from 0.15 to 40. 

Fischer R, Danger J, Malassa G, Walther D, Gorls H, Vaughan G (2006). A key step in the formation of acrylic acid from CO2 and ethylene the transformation of a nickelalactone into a nickel-acrylate complex. Chem Commun 2510-2512... 

In studies of oiganotin products derived from poly(acrylic acid) or copolymers of acrylic acid and ethylene, we found that the organotin moiety was always present as a tetrahedral and not present in a trigonal bipyramid or octahedral structures. " ... 

Complex-forming POE/PAA interpenetrating polymer networks have been prepared by matrix polymerization of acrylic acid and ethylene diacrylate (a crosslinking agent) with a precrosslinked POE that was formed from hydroxyl-terminated POE and 2-isocyanatoethyl-2,6-diisocyanatohexanoate (131). At low degrees of POE crosslinking, dynamic mechanical properties in-... 

Calcium oxide can absorb CO2 from pre-combustion systems. Natural sources of CaO, such as limestone, CaCOg, produce sorbents that lose reactivity relatively fast. Good CO2 sorbents were prepared with CaO precursors templated on three natural polysaccharides chitosan, agar and carrageenan, or three synthetic polymers poly(acrylic acid), poly(ethylene glycol) and poly(ethylene oxide-b-propylene oxide-b-ethylene oxide), respectively. Calcium oxide confined onto S5mthetic polymers exhibited better CO2 uptake activity and stability than CaO derived from commercial... 

The addition of alcohols to form the 3-alkoxypropionates is readily carried out with strongly basic catalyst (25). If the alcohol groups are different, ester interchange gives a mixture of products. Anionic polymerization to oligomeric acrylate esters can be obtained with appropriate control of reaction conditions. The 3-aIkoxypropionates can be cleaved in the presence of acid catalysts to generate acrylates (26). Development of transition-metal catalysts for carbonylation of olefins provides routes to both 3-aIkoxypropionates and 3-acryl-oxypropionates (27,28). Hence these are potential intermediates to acrylates from ethylene and carbon monoxide. 

Specialty waxes include polar waxes for more polar adhesive systems. Examples would be castor wax (triglyceride of 12-hydroxy stearic acid) or Paracin wax N- 2 hydroxy ethyl)-12-hydroxy stearamide) which are used in polyester, polyamide, or with high VA EVA copolymer-based systems. Other common polar waxes are maleated polyethylenes, which are used to improve the specific adhesion of polyethylene-based adhesives, and low molecular weight ethylene copolymers with vinyl acetate or acrylic acid, which are used to improve low temperature adhesion. High melting point isotactic polypropylene wax (7 155°C) and highly refined paraffin wax (7,n 83°C) are used where maximum heat resistance is critical. Needless to say, these specialty waxes also command a premium price, ranging from 2 to 5 times that of conventional paraffin wax. 

In a partially crystalline homopolymer, nylon 6, property enhancement has been achieved by blending with a poly(ethylene-co-acrylic acid) or its salt form ionomer [24]. Both additives proved to be effective impact modifiers for nylon 6. For the blends of the acid copolymer with nylon 6, maximum impact performance was obtained by addition of about 10 wt% of the modifier and the impact strength was further enhanced by increasing the acrylic acid content from 3.5 to 6%. However, blends prepared using the salt form ionomer (Sur-lyn 9950-Zn salt) instead of the acid, led to the highest impact strength, with the least reduction in tensile... 

FIGURE 38.6 Morphology of (a) ethylene-propylene-diene monomer (EPDM)-poly(ethylene-co-acrylic acid) blend (b) EPDM-poly(ethylene-co-acrylic acid)-ground rubber tire (GRT) blend. (Reprinted from Naskar, A.K., Bhowmick, A.K., and De, S.K., Polym. Eng. Sci., 41, 1087, 2001. With permission from Wiley InterScience.)... 

The most common polyester fiber is polyethylene terephthalate (PET), prepared from ethylene glycol and terephthalic acid. Acrylics... 

II. B polyethylene glycol, ethylene oxide, polystyrene, diisocyanates (urethanes), polyvinylchloride, chloroprene, THF, diglycolide, dilac-tide, <5-valerolactone, substituted e-caprolactones, 4-vinyl anisole, styrene, methyl methacrylate, and vinyl acetate. In addition to these species, many copolymers have been prepared from oligomers of PCL. In particular, a variety of polyester-urethanes have been synthesized from hydroxy-terminated PCL, some of which have achieved commercial status (9). Graft copolymers with acrylic acid, acrylonitrile, and styrene have been prepared using PCL as the backbone polymer (60). 

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. 

Flocculants cause colloidal clay particles to coagulate thus promoting separation from the drilling fluid which has been circulated down the wellbore and returned to the surface. The treated fluid may then be pumped back down the well bore. Sodium chloride, hydrated lime, gypsum, sodium tetraphosphate, polyacrylamide, poly(acrylamide-co-acrylic acid), cationic polyacrylamides, and poly(ethylene oxide) have been used commercially. 

---