Design and building of an isoperibolic calorimeter: measurements of enthalpy of formation for derivatives of glycidol

Abstract

The enthalpy of formation can be determined indirectly with different calorimetric techniques; one of the most used is combustion calorimetry. During a combustion process, there are multiple energy variables that can significantly influence the overall result of the measurement. One of these variables is the energy exchange that exists between the calorimeter and the surroundings. To reduce this energy contribution and obtain more precise measurements of combustion energies of compounds containing the elements C, H, O and N, a combustion calorimeter in isoperibolic operation was designed, constructed and calibrated. The measurements made with this instrument show good precision; the results obtained for internal energy and the combustion enthalpy of succinic acid (solid sample) and for glycidol, glycidyl isopropyl ether, glycidyl butyrate and glycidyl methacrylate (liquid samples) are presented. The error percentage for the ε calor of the calorimetric system proposed was compared with a commercial calorimeter and published results in the literature.

Calculation of the Isobaric Heat Capacities of the Liquid and Solid Phase of Organic Compounds at 298.15K by Means of the Group-Additivity Method

“…A number of new experimental C p data have been published for saturated and unsaturated hydrocarbons, especially for bicyclo [ [14], and adamantane [15]. In addition, further C p values have been found for the amines hexamethylenetetramine [15], tetra-N-phenylbenzidine and 4,4 -bis (N-carbazolyl)-1,1 -biphenyl [16], 1,3,5-triazine [17], the ethers 1,3,5-trioxane [17], diethylene glycol n-pentyl ether [18], triethylene glycol monopentyl ether [19] and diphenyl ether [20], several alcohols and aldehydes [21], derivatives of glycidol [22], carboxylic acids [23,24], aliphatic esters [24][25][26][27], benzoates [28], haloalkanes [29,30], haloaromatics [31,32], thio ethers, sulfones and sulfoxides [33,34], alkanolamines, [35][36][37] and nitriles [38] For several compounds, more recent publications have been found the following: 4-ethylmorpholine [39], methionine [40], theophylline, and caffeine [41], as well as for (-)-menthone, (+)-pulegone, and (-)-isopulegol [42]. Beyond these, experimental C p values of a number of new compounds have been published: namely 3-amino-4-amidoximinofurazan [43], 3-fluoro-5-(3-pyridinyloxy)-benzenamine and N- [46], eugenol and (+)-carvone [47], indapamide [48], and the explosives EDNH and DNTA [49].…”

Calculation of the Isobaric Heat Capacities of the Liquid and Solid Phase of Organic Compounds at 298.15K by Means of a Generally Applicable Computer Algorithm Based on the Group-Additivity Method

“…A number of new experimental Cp data have been published for saturated and unsaturated hydrocarbons: in particular for bicyclo [ [13], and adamantane [14]. In addition, further Cp values have been found for the amines hexamethylenetetramine [14], tetra-N-phenylbenzidine and 4,4′-bis (N-carbazolyl)-1,1′biphenyl [15], 1,3,5-triazine [16], the ethers 1,3,5-trioxane [16], diethylene glycol n-pentyl ether [17], triethylene glycol monopentyl ether [18] and diphenyl ether [19], several alcohols and aldehydes [20], derivatives of glycidol [21], carboxylic acids [22,23], aliphatic esters [23][24][25][26], benzoates [27], haloalkanes [28,29], haloaromatics [30,31], thio ethers, sulfones and sulfoxides [32,33], alkanolamines [34][35][36] and nitriles [37]. For several compounds, more recent publications have been found: in particular for 4-ethylmorpholine [38], methionine [39], theophylline and caffeine [40], as well as for (-)-menthone, (+)-pulegone and (-)-isopulegol [41].…”

Construction and Calibration of a Semi-micro-combustion Calorimeter to Determine the Enthalpies of Combustion of N,N′-Bis(salicylidene)ethylenediamine and N,N′-Bis(salicylidene)-1,3-propanediamine

“…The same equipment and procedure described to determine purity were used to obtain the thermograms and obtain the melting temperature ( T fus ) and enthalpy of fusion (Δ cr l H m ) of NSE and NSP. Samples and references were prepared as described in previous works . The purity was determined by the fractional melting method, and T fus and Δ s l H m were calculated according to the van’t Hoff method. , To obtain the heat capacity at T = 298.15 K of the NSE and NSP, the differential scanning calorimeter was calibrated using synthetic sapphire ( C p = 0.775 J g –1 K –1 at T = 298.15 K).…”

“…The procedure used in traditional combustion calorimeters to determine the energy of combustion for compounds containing carbon, hydrogen, oxygen, and nitrogen is well known. − The mass required in each experiment is about 1 g, and to ensure the reproducibility of the results, between 5 and 10 repetitions are required. To obtain and purify this amount of sample is in some cases difficult, especially for new substances synthesized in organic chemistry as new drugs, biomaterials, or biochemical compounds that are interesting in terms of their molecular structure or energetic characteristics.…”