Naturally Occurring Polyesters
Abstract
MAY I add to the recent note1 on the isolation of a natural elastic polyester2? The natural occurrence of polyesters was observed as early as 1908 by Boug-ault and Bourdier3, who showed that the waxes obtained by extraction of the leaves of a variety of conifers are linear polyesters of hydroxy-acids such as juniperic acid (ω-hydroxypalmitic acid) and sabinic acid (ω-hydroxylauric acid). These polyesters, or `etholides', have average molecular weights of the order 1,000-2,000, and were afterwards shown to have the same general properties as the synthetic polyesters obtained by heating ω-hydroxy-mono-carboxylic acids4. The average molecular weights of the natural esters show that they belong to the α-polyester type rather than the ω- or linear super-polyester type synthesized by Carothers and Hill5; Bougault appreciated the analogy between the etholides on one hand and polysaccharides and poly-peptides on the other.
- Publication:
-
Nature
- Pub Date:
- March 1945
- DOI:
- 10.1038/155272b0
- Bibcode:
- 1945Natur.155..272S