Synthesis, characterization, and thermal properties of new flavor compounds

Marta Worzakowska

doi:10.1007/s10973-013-3541-1

Abstract

Synthesis, characterization, and thermal properties of new, flavor, long chain esters were presented. The new compounds were obtained in the catalytic esterification process of a stoichiometric ratio of trans-3,7-dimethyl-2,6-octadien-1-ol, succinic anhydride, and aliphatic chain diol. As diols ethylene glycol, 1,4-buthylene glycol, 1,5-pentylene glycol, and 1,6-hexylene glycol were applied. The spectroscopic analyses completely confirmed that the applied synthesis conditions allowed obtaining the new compounds with high yield and purity. Their thermal properties were studied in inert and oxidative atmospheres. The esters were less thermally stable in inert (IDT 186–195 °C) than in oxidative (IDT 210–228 °C) atmosphere. Two, non-completely divided decomposition steps were visible during their pyrolysis. In contrast, the new, long chain compounds decompose in three major steps in air. The analyses of the volatile products emitted during their pyrolysis indicated on the asymmetrical disrupt of their bonds. The formation of acyclic and alicyclic monoterpene hydrocarbons, succinic anhydride, diols, alcohols, alkenes, and water was observed. It indicated mainly on the β-elimination reactions during their pyrolysis. Also, β-elimination reactions of esters are mainly expected in air. Initially, it resulted in the formation of acyclic and alicyclic monoterpene hydrocarbons, hydroxyl compounds (diols, alcohols), and its β-elimination products: aldehydes, alkenes, and water. However, the presence of oxygen in the medium causes the partial decarboxylation and oxygenation of aldehydes and thus the formation of alkenes and carbon dioxide. In addition, the beginning of evaporation of succinic anhydride was detected at T max1. At T max2 the evaporation of succinic anhydride, their partial decarboxylation to CO2, the small amounts of diols, alcohols, and aldehyde fragments were indicated. Finally, succinic anhydride, water, and carbon dioxide were only observed during decomposition of studied esters in air.

Highlights

Esters of organic acids are very important group of compounds due to their properties and wide range of applications
The esters of multifunctional monomers like acrylates and methacrylates of various types, functionality, length, flexibility of spacer groups, containing heteroatoms, cyclic, aliphatic, or aromatic rings are employed as new monomers for preparation of polymeric materials differ in properties [7–16]. They find their place in coatings for flooring and furniture, optical fibers, dental restorative materials, hard and soft contact lenses, photolithography, in biomedical applications as biomembranes, blood-compatible materials, antithrombotic, or antivital agents [30, 31], to the production of porous microspheres in chromatography or as a potential component of polymer blends or composites [17–22]
The studies proved that during the catalyzed esterification process of a stoichiometric ratio of trans-3,7-dimethyl-2,6octadien-1-ol, succinic anhydride, and aliphatic, linear diols: ethylene glycol, 1,4-buthylene glycol, 1,5-pentylene glycol, and 1,6-hexylene glycol, the new, flavor, long chain esters can be prepared with high yield and purity which was confirmed by spectroscopic methods

Summary

Introduction

Esters of organic acids are very important group of compounds due to their properties and wide range of applications. The esters of multifunctional monomers like acrylates and methacrylates of various types, functionality, length, flexibility of spacer groups, containing heteroatoms, cyclic, aliphatic, or aromatic rings are employed as new monomers for preparation of polymeric materials differ in properties [7–16]. They find their place in coatings for flooring and furniture, optical fibers, dental restorative materials, hard and soft contact lenses, photolithography, in biomedical applications as biomembranes, blood-compatible materials, antithrombotic, or antivital agents [30, 31], to the production of porous microspheres in chromatography or as a potential component of polymer blends or composites [17–22].

Methods

Results

Conclusion