Search Results

You are looking at 1 - 10 of 15 items for

  • Author or Editor: T. Kasprzycka-Guttman x
  • Refine by Access: All Content x
Clear All Modify Search

Abstract  

Thermoxidation of linolenic acid inhibited by addition of 2,6-di-t-butyl-4-methylphenol and 2,4,6-trimethylphenol at various concentrations was investigated. The measurements were carried out under non-isothermal conditions in an atmosphere of oxygen. DSC curves permitted the determination of onset point and maximum points of the peaks. The influence of inhibitor concentration on temperature of the start of oxidation was noticed. However, no significant changes in temperatures of the maximum heat flow was observed. Measurements and calculations described in this report prove that the assessment of the antioxidant activity of chain-breaking inhibitors can be performed only from the onset temperatures. Calculations of the activation energy of inhibited linolenic acid thermoxidation were performed in order to elucidate the antioxidant activity of the phenolic compounds.

Restricted access

The molar excess enthalpies of binary mixtures of pyridine with C6–C9 n-alkanes have been measured at 313.15 K in the entire composition range. The measuredH E values were compared with those calculated by means of the Prigogine-Flory-Patterson theory and by the ERAS method.

Restricted access

The thermooxidative decompositions of some edible oils were investigated. Isothermal measurements of convention were made with a Du Pont differential scanning calorimeter. Linseed oil, castor oil, olive oil and cod-liver oil were investigated.

Restricted access

The relationships enthalpy of mixing and excess Gibbs energyvs. composition were studied. We report hereH E andG E for 2-CH3-c-C5H4N (α-picoline)+ (1−x) CH3CH(OH)CH3, (1−x) CH3CHCH3CH2OH, (1 −x) CH3CH2(OH)CHCH3 or (1 −x) CH3C(CH3) (OH)CH3

Restricted access

Abstract  

Oxidation of saturated fatty acids ethyl esters: laurate, myristate, palmitate and stearate was investigated by means of DSC techniques under isothermal and non-isothermal conditions. The activation energies of isothermal oxidation were similar to each other (112–123 kJ mol−1) and no influence of carbon length on the rate of oxidative decomposition was observed. Results obtained from non-isothermal experiments were similar only for the first stage of oxidation.

Restricted access

The relationship enthalpy of mixing and excess molar volume of mixing versus composition were studied at 313.15 K for binary systems of 2,4,6-collidine with normal aliphatic alcohols. It was found that at this temperature the values ofH E andV E are negative and change with the length of the alkyl group of the alcohol.

Restricted access

The excess enthalpy of mixing versus composition was studied at 293.15 K and 303.15 K for some binary mixtures of methanol with pyridine bases. The results are presented in Tables.

Restricted access

Excess heat of mixing of pyridine bases with toluene

Experimental results and theoretical description

Journal of Thermal Analysis and Calorimetry
Authors: H. Wilczura, T. Kasprzycka-Guttman, and A. Myslinski

Abstract  

The excess heats of mixing of pyridine bases with toluene at 298.15 K were measured, and the Prigogine-Flory-Patterson theory was applied to describe the experimental results.

Restricted access