Authors:M. Nogala-Kałucka, K. Dwiecki, A. Siger, P. Górnaś, K. Polewski, and S. Ciosek
Becker, E.M., Ntouma, G. & Skibsted, L.H. (2007): Synergism and antagonism between quercetin and other chainbreaking antioxidants in lipid systems of increasing structural organisation. Fd Chem. , 103 , 1288
The synergism of lithium bromide and antimony trioxide on the flame-retardancy of a cotton fabric (woven, plain 150 g m2) has been investigated in this study. The impregnations of cotton fabric with suitable individual additives and/or their
appropriate admixed formulation were carried out. The flammability test has also been fulfilled using described procedure,
in the earlier published articles. Their outcomes comply with thermogravimetry’s data. Moreover the latest mentioned outcomes
support the catalytic effect of this synergism. Explanation of the data could be in favor of existing flame-retardation’s
theories. Ultimately this synergism is in compliance with the green chemistry and economical viewpoints.
have synergistic, and/or antagonistic effects. Actually an additional effect is the sum of the effects of the mixed components taken independently. Synergism means that the observed effect is greater than individual efficiency of each additive, on the
Further evidence for synergism
Several other lines of evidence support the hypothesis of complex synergisms unlocking entheogenic potentials. First, the community of “oilahuasca” researchers procures ASCs by mixing essential oils that contain
The synergism of the crown ethers (CE) dicyclohexano-18-crown-6 (DC18C6), dibenzo-18-crown-6 (DB18C6) and 18-crown-6 (18C6) has been investigated in the thenoyl trifluoroacetone (HTTA) extraction of americium(III) in benzene medium from an aqueous phase of ionic strength 0.5 and pH 3.50 at room temperature (23°C). The extracted synergistic species have the general formula Am(TTA)3 · CE except for DC18C6 in which case the species Am(TTA)3·2CE was also observed at high CE concentrations. The order of synergism was found to be DC18C6>DB18C6>18C6, which is the order of the basicity of CE as indicated by their ability to extract hydrogen ions from nitric acid solutions.
Authors:R. Veeraraghavan, S. Pai, and M. Subramanian
Synergistic extraction of uranyl ion with 2-thenoyltrifluoroacetone (HTTA) and aliphatic amides with varying basicities, viz. dibutyl hexanamide (DBHA), dibutyloctanamide (DBOA) or dibutyldecanamide (DBDA) has been studied at various fixed temperatures of 20, 30, 40 and 50±0.1°C. Results indicate that the equilibrium constants of the organic phase addition reaction (Ks) with these amides follow their order of basicity (Kh) viz. DBHA (0.09)<0.10) H DBOA (0.13) with log Ks values of 4.91, 4.99 and 5.02, respectively. These values are much higher than those with TBP (3.8) or sulfoxides (4) as donors. This may be attributed to the existence of a resonance form of the amide, which has higher electron density on the carbonyl oxygen. The thermodynamic parameters associated with these systems evaluated by the temperature coefficient method indicate that the organic phase addition reaction with all the three amides is stabilized by both enthalpy and entropy changes as against UO
/HTTA/TBP system, where only the enthalpy change contributes to the stabilization.
Authors:R. Veeraraghavan, S. Pai, and M. Subramanian
Synergistic extraction of uranyl ion with 1-phenyl-3-methyl-4-benzoylpyrazolone-5 (HPMBP) and N,N-dibutyl derivatives of hexanamide (DBHA), octanamide (DBOA) and decanamide (DBDA) has been studied at various fixed temperatures of 20, 30, 40 and (50±0.1)°C. Results indicate that the equilibrium constants of the organic phase addition reaction (log Ks) with these amides follow their order of basicity (Kh) viz. 4.01 (DBHA, Kh=0.09)<4.05 (DBOA, Kh=0.1)<4.09 (DBDA, Kh=0.13). These values of log Ks (4) are lower than those (5) of HTTA system with these amides, which may perhaps be attributed to the effect of steric hindrance exerted by the uranyl pyrazolone ohelate to the incoming rigid amide molecule. High negative H and negative S values for this system indicate the organic phase reaction to be an addition and not a substitution.
Authors:P. Šimon, Marta Fratričová, P. Schwarzer, and H.-W. Wilde
of poly(ester-urethanes), poly(ether-urethanes) and poly(acrylic-urethanes),
as a base for automotive paintings in interior applications, has been studied
by DSC. The samples were clearcoat and black-pigmented paints, unstabilized
and stabilized with HALS Tinuvin 292, UV absorber Tinuvin 1130 and antioxidant
Hostanox O3, exposed to weathering in Xenotest and in Arizona desert. From
the dependences of oxidation onset temperature on the heating rate, the kinetic
parameters enabling to calculate the oxidation induction time for a chosen
temperature have been obtained. From the values of oxidation induction time,
the protection factors of the additives and the residual stability of the
polymer after an ageing stress has been evaluated. It has been shown that
the equivalence between the two methods of weathering depends on the polymer
composition. A new criterion for the evaluation of synergism/antagonism of
additives in the stabilizing mixture has been proposed.
Authors:I. El-Yamani, M. Farah, and E. Abd El-Messieh
The extraction of Be(II) from sulphuric acid solutions by binary mixtures particularly that of the sodium salt of di-(2-ethyl
hexyl)-phosphoric acid (NaDEHP) and tributyl phosphate (TBP), has been described. The dependence of extraction on acidity,
diluent type and solvents concentration was thoroughly examined. The possible extraction mechanism is discussed in the light
of results obtained.