Effect of temperature on the partial molar volumes and the partial molar compressibilities of amino alcohols in aqueous solution

Abstract

This study gives new and important information about the apparent molar volumes and the apparent molar compressibilities of amino alcohols which are substances that have several applications in the chemical and pharmaceutical industries.Density and sound velocity of 3-amino-1-propanol, 2-amino-1-propanol, 3-amino-1,2-propanediol and 1,3-diamino-2-propanol in water were measured in the temperature range from 293.15 K to 308.15 K at 5 K intervals using the vibrating tube technique.The limiting values of the partial molar volumes and the partial molar compressibilities at infinitesimal concentration of the amino alcohols were determined at the selected temperatures. The hydration numbers of the amino alcohols in water were calculated from the acoustic properties, using the method proposed by Pasynski. The results were discussed in terms of the number and position of polar groups in the solute.The effect of the introduction of a second hydrophilic centre on the properties studied was analysed by comparing the behaviour observed in 3-amino-1,2-propanediol and 1,3-diamino-2-propanol with that of 3-amino-1-propanol and 2-amino-1-propanol.