An investigation of the structures and molecular dynamics of natural waxes. I. Beeswax

Abstract

A detailed NMR investigation, supported by DSC and X-ray diffraction measurements, of the combwax of the African bee apis mellifera adansonii is reported. Proton spin-lattice relaxation times in the laboratory and rotating frames, as well as the proton spin-spin relaxation time, have been measured as a function of temperature (333 K>T>110 K). The liquid content of the wax has also been determined as a function of temperature by employing a simple pulse technique. The motional parameters associated with the reorientations of the methyl groups and the chains have been isolated and compared with these parameters for similar motions in Fischer-Tropsch waxes. The T1 rho results revealed a minimum which is associated with the dangling motion of chain ends in the amorphous zone of the wax. The relaxation results strongly suggest that beeswax is branched to a much higher degree than Fischer-Tropsch waxes, including oxidised waxes. The high-resolution 13C spectrum of beeswax in the solid state shows that it resembles oxidised Fischer-Tropsch hard wax closely. The major difference is that a higher percentage of carbon atoms are involved in ester groups in beeswax. Oxidised hard wax contains a higher fraction of carbon atoms with double carbon-carbon bonds. The average chain length in beeswax, determined by ebullioscopic methods, is 40 carbon atoms.

Variable-temperature 13C solid-state NMR study of the molecular structure of honeybee wax and silk

“…It has improved the quality of life for humans for a long time. Therefore, beeswax has been investigated in detail [1][2][3][4][5][6]. Honeybee silk is also a subject of study that has attracted the interest of researchers in these years [7,8].…”

“…The beeswax produced by native Japanese bees (Apis cerana japonica) is considered to contain approximately 70% alkanes and esters and less than 30% of free acids and alcohols [4]. Although beeswax comprises multiple components, over 95% of all carbons in beeswax are internal chain methylene [int-(CH 2 )] carbons [1]. Therefore, we considered that the structural study of beeswax mainly involves the structural elucidation of methylene chains in the wax.…”

Discovery of Beeswax as binding agent on a 6th-century BC Chinese Turquoise-inlaid Bronze sword

“…9, the two XRD patterns are almost identical. There are seven most intensive peaks at 2q ¼ 19.3 (dspacing ¼ 4.5950 nm), 21.7 (d-spacing ¼ 4.0919 nm), 23.8 (dspacing ¼ 3.7354 nm), 29.8 (d-spacing ¼ 2.9955 nm), 35.9 (dspacing ¼ 2.4993 nm), 40.3 (d-spacing ¼ 2.2360 nm), and 43.5 (d-spacing ¼ 2.0786 nm), which are diagnostic to the orthorhombic crystal structure in beeswax (Basson and Reynhardt, 1988;Lu et al, 2010;Ranjha et al, 2010). Both FTIR and XRD analyses indicate that the samples are relatively pure beeswax.…”

Renewable feedstocks for lubricant production

“…The honey bee (Apis mellifera) produces cuticular wax consisting of 23% wax esters (C 36 -C 50 ) and 55% hydrocarbons [303]. Beeswax used for the honeycomb is composed of 35% wax esters (mainly C 40 with methylbranched side chains) and 15% hydrocarbons (mainly C 31 ) [304]. TAGs and wax esters are rather uncommon storage lipids in bacteria, but some bacteria do accumulate some fairly high levels of wax ester as a common storage lipid [305].…”