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Itaconic Acid (itaconic + acid)

Distribution by Scientific Domains

Polymers and Materials Science	62%
Chemistry	31%

Selected Abstracts

Unusual Deactivation in the Asymmetric Hydrogenation of Itaconic Acid

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 5 2009
Thomas Schmidt
Abstract During the asymmetric hydrogenation of itaconic acid with rhodium solvate complexes of the type [Rh(PP)(MeOH)2] BF4 (PP=DIPAMP, Me-DuPHOS) a deactivation with increasing substrate concentration is observed. It is shown that this inhibition phenomenon is due to the in situ formation of an inactive rhodium(III)-alkyl complex. Two crystal structures of single crystals of the responsible complexes (1) and (2) support the deactivation pathway. [source]

Use of PP Grafted with Itaconic Acid as a New Compatibilizer for PP/Clay Nanocomposites

MACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 15 2006
Edwin Moncada
Abstract Summary: Functionalized PP samples with different percentages of grafted IA, i.e., 0.7, 1 or 1.8 wt.-%, with similar molecular weights were used as compatibilizers in PP/clay nanocomposites. PP nanocomposites containing 1 wt.-% of organically modified clays, i.e., montmorillonite, natural hectorite and synthetic hectorite and 3 wt.-% of grafted PP with three different percentages of grafted IA as compatibilizers and two commercial PP samples of different molecular weights were prepared by melt blending. The nanocomposites were characterized by XRD, TEM and tensile mechanical measurements. It was found that the molecular weight of PP used as matrix as well as the percentage of grafted IA of the compatibilizer affected the degree of intercalation/exfoliation of the clay and consequently the mechanical properties of the nanocomposites. Values of 2,137 MPa for the modulus and 51 MPa for the tensile strength were obtained when natural hectorite was used and 2,117 and 40 MPa were obtained when montmorillonite was used. A comparative study was carried out, where PP grafted with maleic anhydride was used as the compatibilizer. Inferior mechanical properties were obtained for nanocomposites prepared by using this compatibilizer, where values of 1,607 MPa for the tensile modulus and 43 MPa for tensile strength were obtained. This result indicated that IA-grafted PP was far more efficient as compatibilizer for the formation of nanocomposites than commercially available maleic anhydride-grafted PP. Model showing interaction of the organically modified clay with grafted PP used as compatibilizer. [source]

Unusual Deactivation in the Asymmetric Hydrogenation of Itaconic Acid

The role of auxiliary monomers and emulsifiers on wet scrub resistance of various latex paints at different pigment volume concentrations

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2009
M. Khorassani
Abstract This work is an attempt to study the effect of different latex types containing various auxiliary monomers and emulsifiers on their pigmentation and their corresponding behavior on scrub resistance. The auxiliary monomers investigated were acrylic acid (AA), methacrylic acid (MAA), and itaconic acid and the emulsifiers contained sodium lauryl sulfate (SLS) and sodium dodecylbenzene sulfonate (SDBS). It was shown that a semibatch polymerization technique which led to smaller particles and sharper size distributions is preferable. The best wet scrub results were obtained by using MAA and SLS. It was also shown that the proper selection of an auxiliary monomer generally depended on the range of incorporated pigment volume concentration (PVC). At high PVCs, AA gave better performances compared with MMA. The reverse effect was shown to occur at low PVCs. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 [source]

Polymerization of itaconic acid initiated by a potassium persulfate/N,N -dimethylethanolamine system

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2008
S. J. Veli
Abstract The synthesis and characterization of poly(itaconic acid) (PIA) with a novel initiator/activator system is presented. The initiator in this system was potassium persulfate, whereas the activator was N,N -dimethylethanolamine (DMEA). PIA was synthesized in distilled water and in 0.1M HCl at 40°C with reaction times of 72 and 96 h. PIA was investigated with differential scanning calorimetry, gel permeation chromatography, and pulse gradient spin echo-NMR and compared to the same polymer synthesized in dioxane with 2,2,-azobisisobutyronitrile as the initiator. It was shown that, despite the fact that some residual DMEA remained in the system, the properties of the PIA polymerized in the aqueous phase were very similar to the dioxane-synthesized polymer, which will enable a faster, cheaper, and environmentally more acceptable polymerization of itaconic acid. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source]

Thermal and dynamic mechanical properties of organic,inorganic hybrid composites of itaconate-containing poly(butylene succinate) and methacrylate-substituted polysilsesquioxane

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 4 2008
Takenori Sakuma
Abstract Itaconate-unit-containing poly(butylene succinate) (PBSI) was synthesized by the reaction of 1,4-butanediol, succinic acid, and itaconic acid in a molar ratio of 2.0 : 1.0 : 1.0, and the obtained PBSI was reacted with methacryl-group-substituted polysilsesquioxane (ME-PSQ) in the presence of benzoyl peroxide (BPO) at 130°C to produce PBSI/ME-PSQ hybrid composites. The thermal and dynamic mechanical properties of the PBSI/ME-PSQ hybrid composites were investigated in comparison with those of PBSI cured at 130°C in the presence of BPO. As a result, the hybrid composites showed a much higher thermal degradation temperature and storage modulus in the rubbery state than the cured PBSI (C-PBSI). The thermal degradation temperature and storage modulus of the hybrid composites increased with increasing ME-PSQ content. The glass-transition temperature, measured by dynamic mechanical analysis of the hybrid composites, somewhat increased with increasing ME-PSQ content. However, the glass-transition temperatures of all the hybrid composites were lower than that of C-PBSI. Although the IR absorption peak related to CC groups was not detected for C-PBSI, some olefinic absorption peaks remained for all the hybrid composites. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source]

Gluconic acid production by Aspergillus terreus

LETTERS IN APPLIED MICROBIOLOGY, Issue 3 2010
C. Dowdells
Abstract Aim:,Aspergillus terreus produces itaconic acid at low pH but lovastatin and other secondary metabolites at higher pH in the fermentation. The utilization of glucose as a carbon substrate was investigated for secondary metabolite production by A. terreus. Methods and Results:, With a starting pH of 6·5, glucose was rapidly metabolized to gluconic acid by the wild-type strain and by transformants harbouring Aspergillus niger genes encoding 6-phosphofructo-1-kinases with superior kinetic and regulatory properties for bioproduction of metabolites from glucose. On exhaustion of the glucose in batch fermentations, the accumulated gluconic acid was utilized as a carbon source. Conclusions:, A novel pathway of glucose catabolism was demonstrated in A. terreus, a species whose wild type is, without any strain development, capable of producing gluconic acid at high molar conversion efficiency (up to 0·7 mol mol,1 glucose consumed). Significance and Impact of the Study:,Aspergillus terreus is a potential novel producer organism for gluconic acid, a compound with many uses as a bulk chemical. With a new knowledge of glucose catabolism by A. terreus, fermentation strategies for secondary metabolite production can be devised with glucose feeding using feedback regulation by pH. [source]

Poly(acrylamide- co -itaconic acid) and Semi-IPNS with Poly(ethylene glycol): Preparation and Characterization

MACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 16 2004
Melina Kalagasidis Kru
Abstract Summary: A pH-responsive poly(acrylamide- co -itaconic acid) (PAAm/IA) hydrogel and semi-interpenetrating networks (semi-IPNs) with 5, 10 and 15 wt.-% of poly(ethylene glycol) (PAAm/IA/PEG), were synthesized. Their swelling behavior was studied in the pH range from 1.76 to 7.81, as well as their oscillatory swelling behavior at pH,=,7.81 and pH,=,1.7. Throughout these studies, the gels maintained their mechanical strengths and shape. The shear storage (G,) and loss (G,) moduli, obtained as a function of frequency, for the gels as formed and at equilibrium swelling were higher for the semi-IPNs than for the copolymer hydrogel. The shear storage moduli of copolymer hydrogel and semi-IPNs as formed were independent of frequency over the whole experimental range, whereas the values for the gels at equilibrium swelling decreased with increasing degree of swelling, i.e., the PAAm/IA hydrogel which exhibited the largest swelling had the lowest G, value. The G, and G, values also depended on the content of PEG. Diffusion exponent vs. pH for PAAm, copolymer hydrogel PAAm/IA and semi-IPN with PEG. [source]

New Poly(sodium carboxylate)s Based on Saccharides, 1.

MACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 18 2002
Characterization of Ionic Allyl Glycoside Polymers, Synthesis
Abstract New poly(sodium carboxylate)s, containing monosaccharide side groups with ether linkages to the main chain, are presented as substitutes for water-soluble homo- and copolymers of acrylic acid. Neutral and ionic allyl glycoside monomers, namely allyl- , - D -galactopyranoside and allyl- , - D -glucofuranosidurono-6,3-lactone, were synthesized by Fischer glycosidation. These monomers were copolymerized with maleic anhydride and itaconic acid in aqueous and nonaqueous solution. The corresponding copolymers with different structures, degrees of functionalization, and charge densities were characterized by 13C NMR spectroscopy, molecular-weight measurements, and intrinsic viscosity [,] determination. From these, the monomer reactivity ratios and Mark,Houwink relations were established (see Figure). Copolymerization curves of maleic acid copolymers 6 and 10. M1: mole fraction of allyl monomer 2, and 5, in the feed; m1: mole fraction of allyl monomer in the copolymer. The dashed line shows the course of an ideal alternating copolymerization (excepted: M1,=,0 mol-%, M1,=,100 mol-%). [source]

High char-yielding poly[acrylonitrile- co -(itaconic acid)- co -(methyl acrylate)]: synthesis and properties

POLYMER INTERNATIONAL, Issue 8 2005
Renjith Devasia
Abstract Polyacrylonitrile terpolymers of various compositions consisting of acrylonitrile (AN), itaconic acid (IA) and methyl acrylate (MA) were synthesized by solution polymerization in dimethylsulfoxide. Increase in concentration of either IA or MA retarded the overall polymerization rate and the polymer molecular weight. The system consisting of AN + MA and varying IA concentration was more prone to retardation in comparison with the system composed of AN + IA with variable MA concentration. The retardation factors were quantified. Minor quantities of MA boost the reactivity of IA in the terpolymer system. The terpolymer was richer in MA vis-à-vis the feed. The thermal characteristics of the terpolymer were examined as a function of its composition. In contrast to the copolymer of AN and IA requiring 1,1.5 mol% IA, the terpolymer required an IA content of approximately 2.5 mol% for optimum thermal stability. The polymer with 90 mol% AN, 2.5 mol% IA and 7.5 mol% MA exhibited reasonably good char-forming characteristics and thermal stability. The overall crystallinity and crystallite size of the polymers were found to decrease on incorporation of the comonomers. The ,aromatization index' of the copolymer increased with the temperature of pyrolysis through re-organization of the tetrahydropyridine ladder structure. Copyright © 2005 Society of Chemical Industry [source]

Three lanthanide complexes derived from itaconic acid and 2,2,-bipyridine

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 3 2009
Juan Carlos Muñoz
The structures of three new polymeric lanthanide complexes, poly[[bis(2,2,-bipyridine)-,4 -itaconato-di-,3 -itaconato-digadolinium(III)] tetrahydrate], {[Gd2(C5H4O4)3(C10H8N2)2]·4H2O}n, (I), poly[diaqua(2,2,-bipyridine)di-,3 -itaconato-,2 -itaconato-digadolinium(III)], [Gd2(C5H4O4)3(C10H8N2)(H2O)2]n, (II), and poly[[bis(2,2,-bipyridine)-,4 -itaconato-di-,3 -itaconato-diholmium(III)] dihydrate], {[Ho2(C5H4O4)3(C10H8N2)2]·2H2O}n, (III), have been solved from twinned specimens. Compound (I) presents a two-dimensional polymeric structure parallel to (011) built up around two independent nine-coordinated Gd centres displaying similar GdO7N2 environments, with both N-donor atoms in each provided by a chelating 2,2,-bipyridine (bpy) unit. The coordinating O atoms are from three different itaconate (ita) anions (itaconic acid is 2-methylidenebutanedioic acid). Compound (II) also presents two independent Gd centres (one ten- and the other eight-coordinated), but the overall formula and individual coordinations are different from those of (I). The chemical unit is in this case completed by one bpy ligand, three ita anions (one of them displaying a new, hitherto unreported, ,3 - O,O,:O,,O,,:O,,, binding mode) and two aqua ligands. The whole structure is built up around a twofold rotation axis passing through both cations, as well as through the centre of the bpy ligand and one of the ita anions, thus making only half of the chemical unit independent. Finally, compound (III) presents a single independent Ho centre, a bpy unit and one and a half ita anions (one of them bisected by a twofold rotation axis) in the asymmetric unit, plus two (disordered) nonbonded solvent water molecules. In compounds (II) and (III), those ita anions bisected by a symmetry element incompatible with the internal symmetry of the ligand exhibit disorder in the C=CH2 group. [source]

Novel Contributions to the Mechanism of the Enantioselective Hydrogenation of Dimethyl Itaconate with Rhodium Complexes

CHEMISTRY - A EUROPEAN JOURNAL, Issue 15 2008
Thomas Schmidt
Easy transformation of itaconic acid and its derivatives, such as dimethyl itaconate, into pharmaceutically interesting chiral methyl succinates by enantioselective hydrogenation is described. The X-ray structure of the major catalyst,substrate complex, [Rh((S,S)-dipamp)(dimethyl itaconate)]BF4, of the reaction is shown. [source]