Synthesis of stabilizers based on glycerides of monocarboxylic acids for industrial chloroparaffins

Abstract

Objectives. The study aimed to develop new effective heat stabilizers based on glycerol esters of monocarboxylic acids for industrial chlorinated paraffins and to select of the optimal ratio of active ingredients in the stabilizing composition in order to provide the maximum thermostabilizing effect.Methods. The thermostabilizing effect of the studied samples on chlorinated paraffins was evaluated according to the standard method for determining the thermal stability of liquid chlorinated paraffins in terms of the mass fraction of split off hydrogen chloride. Quantitative and qualitative analysis of the obtained mixtures of monocarboxylic acid glycerides was carried out using chromato-mass spectrometry.Results. Glycerides of monocarboxylic acids (oleic, octanoic, hexanoic, and propionic acids) were obtained and identified, and the compositions of the resulting mixtures of mono-, di- and triesters were determined. The stabilizing effect of the obtained mixtures of glycerides of monocarboxylic acids in the amount of 0.5–2.0 wt parts per 100 wt parts of unstabilized industrial chlorinated paraffin CP-30 was determined. The combined use of glycerides of monocarboxylic acids with calcium-containing compounds as a complex stabilizer with a molar ratio of esters/Ca 0.93–0.86/0.07–0.14, respectively, was investigated. Chloroparaffin CP-470, stabilized by the developed complex stabilizer, was successfully used in a polyvinyl chloride composition for cable compound of the brand OM-40.Conclusions. A proposed variant of a complex stabilizer for chlorinated paraffins based on Russian raw materials for import substitution will expand the range of effective stabilizers for organochlorine substances. Glycerides of monocarboxylic acids are shown to exhibit a thermostabilizing effect on industrial chlorinated paraffins. The relationship between the length of the hydrocarbon substituent of the carboxylic acid in the ester and the thermostabilizing effect is obtained. With an increase in the number of carbon atoms in the hydrocarbon substituent of the carboxylic acid, the heat-stabilizing ability decreases. The minimum sufficient concentration of glycerides of carboxylic acids was 0.05 ± 0.005 mol/kg, above which no increase in the thermostabilizing effect on chloroparaffin was observed. A synergistic ratio of the components of the stabilizing mixture in terms of thermal stability—glycerides of monocarboxylic acids/calcium-containing compounds—was found equal to 0.85–0.9/0.15–0.1.

Keywords

• chloroparaffins
• thermal stability
• esterification
• glycerol esters
• calcium glyceroxide