Acrylic acid from ethylene, mechanism

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. 

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-... 

Poly (methyl methacrylate) was also subjected to mechanical reaction in a vibrating mill in common solvent for several monomers (ethylene, acrylic acid and its esters, acrylonitrile and styrene) at temperatures from —196 to 20° C (22). The formation of macroradicals and their reactions were followed by EPR (electron paramagnetic resonance). The macroradicals reacted with vinyl monomers at temperatures less than —100° C, while quinones underwent reaction as low as —196° C. The same experiments were performed also with polystyrene and polybutylenedimethacrylate. The radicals from polystyrene were more reactive than those from poly(methyl methacrylate). 

Similar mechanical data for a series of ionomers derived from a single ethylene—acrylic acid copolymer have appeared (13) (Table 3). Comparison of the data from Tables 2 and 3 shows that the substitution of acrylic acid for methacrylic acid has only minor effects on properties. 

The metallic layers were examined either by conventional or cross-section TEM in a Jeol 200 Cx microscope. For the cross section preparation a sandwich of two laminates is made, glued face to face with an epoxy, cut in small pieces, mechanically polished, and then ion milled to a final TEM observation thickness. The plane section TEM sample are prepared by dissolving the PET in trifluoroacetic acid for 5 to 10 mn. The area observed, on plane section TEM, for the grain size calculation is close to 0.2 urn. For the adhesion measurements, test pieces consist of aluminum support (1 mm thick) double sided tape (Permacel P-94) PET (12pm) / evaporated aluminum/ ethylene acrylic acid (EAA) copolymer film. These laminates are prepared for the peel test by compression under 1.3 105 N.m2 at 120°C for 10 seconds. The peel test is performed by peeling the EAA copolymer sheet from the laminate in an INSTRON tensile tester at 180° peel angle and 5 cm min peel rate. 

Yan et al. [52] explored the use of IPN techniques to produce a composite vinyl-acrylic latex. The first-formed polymer was produced using VAc and divinyl benzene (DVB), while the second formed polymer constituted a BA/DVB copolymer. In both cases the DVB was added at 0.4 wt%. They compared this product with another product, a bidirectional interpenetrating netwodc (BIPN) in which VAc was again polymerized over the first IPN. They noted that the compatibility between the phases was more pronounced in the BIPN than in the IPN as determined using dynamic mechanical measurements and C nuclear magnetic resonance spectroscopy. The concept of polymer miscibility has also been used to produce composite latex particles and thus modify the pafamance properties of VAc latexes. Bott et al. [53] describe a process whereby they bloid VAc/ethylene (VAc/E) copolymers with copolymers of acrylic acid or maleic anhydride and determine windows of miscibility. Apparently an ethyl acrylate or BA copolymer with 10-25 wt% AA is compatible with a VAc/E copolymer of 5-30 wt% ethylene. The information obtained from this woik was then used to form blends of latex polymers by polymerizing suitable mixtures of monomers into preformed VAc/E copolymers. The products are said to be useful for coating adhesives and caulks. 

An MIP adsorbent is prepared for the extraction of 7-diethylamino-4-methyl-coumarin (Fig. 3). The print molecule, 7-diethylamino-4-methylcoumarin (4 mmol, 0.925 g), a functional monomer, 2-(trifluoromethyl) acrylic acid (12 mmol, 1.681 g), a cross-linking monomer, ethylene glycol dimethacrylate (60 mmol, 11.893 g) and a polymerization initiator, 2,2 -azobis(2,4-dimethylvaleronitrile) (0.140 g) are dissolved in anhydrous toluene (18 mL) in a 50-mL borosilicate PYREX tube.The solution is briefly purged with dry nitrogen for 5 min and sealed with a screw cap. The PYREX tube is transferred to a water bath preset at 45°C and maintained for 16 h. After polymerization, the polymer monolith is taken from the PYREX tube and fractured. This is further ground with a mechanical mortar (Retsch, Haan, ERG) and wet-sieved with 5% ethanol (v/v), and subjected to repetitive sedimentation in... 

The suggested mechanism (Scheme 11) involves migratory insertion of coordinated ethylene into a palladium-carboxyl bond formed by the reaction of the Pd—CO species with water. Acrylic acid results from j8-hydride elimination of the carboxypalladation intermediate, whereas oxidative cleavage by AcOH results in the formation of j8-acetoxypropionic acid. ... 

Jang, S. S., William, I., Goddard, A., et al. (2007) Mechanical and Transport Properties of the Poly(ethylene oxide)-Poly(acrylic acid) Double Network Hydrogel from Molecular Dynamic Simulations, J. Phys. Chem. B, 111, 1729-37. 

Poly(methyl methacrylate) was also subjected to mechanical reaction in a vibrating mill in a common solvent for several monomers (ethylene, acrylic acid and its esters, acrylonitrile, and styrene) at temperatures from —196... 

Figure5.6 Dynamic mechanical analysis (tan 5 versus temperature) for poly(vinyl amine) blends with ethylene/acrylic acid copolymers (reproduced (replotted) from Robeson, L. M., Kuphal, J. A. and Vratsanos, M. S., J. Appl. Polym. Sci. (1996) 61, p. 1561, with permission by John Wiley Sons, Inc.)...

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