Unsaturated amorphous copolyesters of varied composition were prepared by transesterification copolymerization of diethyl fumarate, and two diols, 1,2‐propanediol and 2‐methyl‐1,3‐propanediol. The copolyesters were characterized by IR, 1H‐ and 13C‐NMR, GPC, DSC, and TGA. The glass transition is changing with composition from 0°C to 19°C as the content of 1,2‐propanediol residue in the copolyester increases. The copolyester structure and composition have an impact on the compressive strength and hydrolytic stability of the composites prepared by crosslinking the fumarate double bonds with N‐vinyl pyrrolidone in the presence of inorganic filler, calcium sulfate dihydrate, with the addition of a radical initiator, benzoyl peroxide, at ambient temperatures. 相似文献
Summary: The radical homo‐ and copolymerization of styrene ( 1 ) and diethyl fumarate (DEF, 2 ) in the presence of methylated β‐cyclodextrin (β‐CD) in water is described. It has been shown for the first time that homopolymerization of CD‐complexed DEF and its copolymerization with CD‐complexed styrene occur readily in aqueous solution. In the absence of CD, or in organic solvents, the homopolymerization of DEF is strongly retarded.
Radical polymerization of isopropyl tert-butyl fumarate (iPtBF) and monomer-isomerization radical polymerization of isopropyl tert-butyl maleate (iPtBM) were investigated with 2,2′-azobisisobutyronitrile as initiator in the presence and absence of morpholine (Mor) as isomerization catalyst. It was found that iPtBF gave high molecular weight polymers in high yield as previously observed for diisopropyl fumarate (DiPF) and di-tert-butyl fumarate (DtBF). It was confirmed that iPtBF produced by in situ monomer isomerization of iPtBM homopolymerized to give a polymer. Radical copolymerization of iPtBM with styrene in the presence and absence of Mor was also performed and monomer reactivity ratios obtained were compared. From the kinetic study of the isomerization of iPtBM, it was revealed that the isomerization rate showed first-order dependence on the concentration of iPtBM and Mor, and that the apparent activation energy was 29.4 kJ/mol. On pyrolysis of the poly(iPtBF) at 180°C, isobutene and isopropanol were eliminated rapidly to yield polymer containing carboxyl groups and anhydrides. The pyrolytic behavior was different from that of a copolymer of DiPF with DtBF. 相似文献
In this study, a facultative bacterium that converts fumarate to succinate at a high yield was isolated. The yield of biocon
version was enhanced about 1.2 times by addition of glucose into culture medium at an initial concentration of 6 g/L. When
the initial cell density was high (2 g/L), the succinate produced at pH 7.0 for initial fumarate concentrations of 30, 50,
80, and 100 g/L were 29.3, 40.9, 63.6, and 82.5 g/L, respectively, showing an increase with the initial fumarate concentration.
The high yield of 96.8%/mole of fumarate in just 4 h was obtained at the initial fumarate concentration of 30 g/L. Comparing
these values to those obtained with low cell culture (0.2 g/L), we found that the amount of succinate produced was similar,
but the production rate in the high cell culture was about three times higher than was the case in the low cell culture. This
strain converted fumarate to succinate at a rate of 3.5 g/L·h under the sparge of CO2. 相似文献
Microwave assisted free radical copolymerization of diisopropyl fumarate (DIPF) and benzyl acrylate (BzA) with different copolymer compositions was performed using benzoyl peroxide as initiator. The effect of the reaction conditions on the macromolecular characteristics, monomer reactivity ratio and copolymer properties were studied. The monomer conversion and average molecular weights increase with the content of BzA units in the copolymer. The copolymers were characterized by IR, 1H and 13C-NMR spectroscopies and the molecular weights were analyzed with size exclusion chromatography (SEC). The reactivity ratios obtained from an extended Kelen-Tüdös method under microwave irradiations are a factor which is double than those obtained by thermal copolymerization. The product r1r2 = 0.152 suggests a preference of both propagating macroradicals toward consecutive homopolymerization. The hydrodynamic and polydispersity size were measured in ethylacetate, tetrahydrofuran and methylethylketone with a quasi-elastic light scattering (QELS) technique showing that the quality of the solvents increases in the order: EA < THF < MEK. 相似文献
The synthesis of nickel supramolecular compound with hexamethylenetetramine and fumarate ligands is reported. The compound [Ni(H2O)6(fum)]·2(hmt)·4H2O (1) (fum=fumarate; hmt=hexamethylenetetramine) were characterized by elemental analysis, crystal structure, IR. Compound 1 crystallizes in the triclinic system, space group P1, and with Z=1. Cell parameters: a=0. 934 6(1), b=0.933 8(1), c=0.938 8(2) nm, α=79.46(1)°, β=77.84(1)°, γ=61.29 6(7)°. Every metal ion has a octahedral coordination geometry formed by six oxygen atoms from six water molecules, and the relative independent components [Ni(H2O)6]2+, fumarate anions, hmt and H2O molecules are linked together by two kinds of hydrogen bonds (O-H…O, and O-H…N) to form a three-dimensional structure. CCDC: 256355. 相似文献