Poly 3-propionic acids

The successful use of crop plants as a production method for biopolymer not only depends on the amount of PHA accumulated in plants but also on the type and quality of the PHA synthesized. Since poly(3HB) is a polymer with poor physical characteristics [16], it was important to engineer plants for the synthesis of PHA co-polymers with better physical characteristics. Poly(3-hydroxybu-tyrate-co-3-hydroxyvalerate) [poly(3HB-co-3HV)] is the best studied co-poly-mer. Poly(3HB-co-3HV) has lower crystallinity, and is more flexible and less brittle than poly(3HB) homopolymer [16]. Synthesis of poly(3HB-co-3HV) in bacteria was first achieved by fermentation of R. eutropha on glucose and propionic acid [2]. For a number of years, production of poly(3HB-co-3HV),... 

Liu et al. prepared palladium nanoparticles in water-dispersible poly(acrylic acid) (PAA)-lined channels of diblock copolymer microspheres [47]. The diblock microspheres (mean diameter 0.5 pm) were prepared using an oil-in-water emulsion process. The diblock used was poly(t-butylacrylate)-Wock-poly(2-cinna-moyloxyethyl) methacrylate (PtBA-b-PCEMA). Synthesis of the nanoparticles inside the PAA-lined channels of the microspheres was achieved using hydrazine for the reduction of PdCl2, and the nanoparticle formation was confirmed from TEM analysis and electron diffraction study (Fig. 9.1). The Pd-loaded microspheres catalyzed the hydrogenation of methylacrylate to methyl-propionate. The catalytic reactions were carried out in methanol as solvent under dihydro-... 

Torchilin et al. synthesized an iodine-containing amphiphilic block-copolymer consisting of iodine-substituted poly-L-lysine which is able to form micelles in aqueous solution [37]. The two components of the block-copolymer were methoxy-poly(ethylene glycol) propionic acid (MPEG-PA) with a molecular weight of 12 kDa and poly[ ,M-(2,3,5-triiodobenzoyl)]-L-lysine. The particle size of the micelles was approx. 80 nm, and the iodine concentration was 20 mg mL . Biodistribution studies in rats showed significant and prolonged enhancement of the aorta, the liver and spleen. 

The intrinsic viscosity of poly(L-proline) is studied as a function of molecular weight and temperature In five commonly used solvents water, trifluoroethanol, acetic acid, propionic acid, and benzyl alcohol. The characteristic ratio is 14 in water and 18-20 in the organic solvents at 303 K, and d (in 0) / d T is negative. The theoretical rotational potential function obtained by Hopfinger and Walton for u-prolyl-L-prolyl-t-prolyl-t-proline J. Macromol. Scl. Phys. 1969, 3, 171 correctly predicts the characteristic ratio at 303 K but predicts the wrong sign for tfiln < >0) IdT. 

Cecchi, R., L. Rusconi, M. C. Tanzi, F. Danusso, and P. J. Ferruti. 1981. Synthesis and pharmacological evaluation of poly(oxyethylene) derivatives of 4-isobutylphenyl-2-propionic acid (ibuprofeW )ed. Chem.24 622-625. 

Together with China Petroleum Chemical Corp. (Sinopec) in a 50-50 partnership, BASF planned to build its first Verbund project in East Asia - an integrated petrochemical site (IPS) on 220 hectares of land. The core of the project was an ethylene cracker with a capacity of 600,000 tons per year. Nine new plants downstream would be supplied by the cracker, producing 1.7 million metric tons of chemical products for local consumption, including ethylene, aromatics, poly-ethylenes, ethylene oxide and ethylene glycols, acrylic acid, acrylates, oxo alcohols, formic acid, propionic acid, methylamine, and dimethylformamide. 

The copolymer poly-(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHB-co-PHV) produced by A eutrophus has generated more interest than poly-(R)-3-hydroxybutyrate (PHB) homopolymer. Since these bacterial polyesters are biodegradable thermoplastics, their mechanical and physical properties have received much attention. PHB is a relatively stiff and brittle material because of its high crystallinity. However, the physiochemi-cal and mechanical properties of [P(HB-HV)] vary widely and depend on the molar percentage of 3-hydroxyvalerate (HV) in the copolymer (4,5) as shown inTable 1. Propionic acid is converted by a synthetase to propionyl-CoA, and the biosynthetic P-ketothiolase catalyzes the condensation of propionyl-CoA with acetyl-CoA to 3-ketovaleryl-CoA by the acetoacetyl-CoA reductase. The hydroxyvaleryl moiety is finally covalently linked to the polyester by the PHA synthase (6). 

Hydroxy-propionic acid 1,3-Propanediol, acrylamide, acrylic acid, acrylonitrile, ethyl-3-hydroxypropionic acid, L-alanine, L-serine, malonic acid, propiolactone, poly(3-HP), poly(3-hydroxybutyric acid-co-3-hydroxypropionic acid) Polymers, fine chemicals Cao et al., 1999 Werpy and Petersen, 2004 Zhang etal., 2004 Patel etal., 2006... 

FIGURE 7.25 Release of propionic acid and weight loss of poly(orthoester) containing lactoyl-lactic dimers (PE095LAC5). [Graph reconstructed from data by Schwach-Abdellaoui et al., Proceed. Int. Symp. Control. Rel. Bioact. Mater., 25, 713 (1998).]... 

C3 Lactic acid 3-Hydroxypropionic acid Glycerol 1.2- Propanediol 1.3- Propanediol Propionic acid Acetone L-lsoleucine L-Leucine L-Proline L-Serine L-Valine L-Arginine L-Tryphophane L-Aspartic acid Cyanophycin Gellan Heparin Hyaluronic acid Poly-gamma-Glutamic acid Poly-epsilon-lysine Polyhydroxyalkanoates Pullulan... 

Product quality of PHAs is very much dependent on the polyester composition (see 3.2.2.1). In 1987, Byrom found that poly-(3HB-co-3HV) can be produced in large-scale fed-batch culture by supplementing the nutritional medium of a glucose-utilising mutant of Alcaligenes eutrophus (today known as Cupriavidus necator) with propionic acid (precursor for 3HV formation) [50]. Later it was shown that the utilisation of valeric acid instead of propionic acid results in a higher proportion of 3HV units [51]. The improvements in product quality of co- and terpolyesters, however, results in an increase of the production costs of the polymer because of the high price of the precursors. 

In another study, Liu et al. [66] used a PEM in place of an OTS SAM to create a new type of membrane for encapsulation of cultured cells. The PEM was composed of several alternating layers of poly(lysine) and alginate, capped with an amphiphilic terpolymer synthesized from yV,/V-dioctadecylcarbamoyl propionic acid, hydrox-yethylacrylate, and styrene sulfonate. The octadecyl chains provided a hydrophobic surface on which the acrylatePC was fused, then photopolymerized (Fig. 2). Coating alginate beads with the PEM/HBM multilayer significantly reduced the release... 

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