Biodegradability of poly(butylene n-alkylenedionate)s composed of long-methylene chains as alternative polymers to polyethylene

Abstract

Poly(butylene n-alkylenedionate)s (PBADs), which are polymers that are potentially biodegradable in various environments, exhibit excellent thermal and mechanical properties similar to those of polyethylene because of their long alkyl chains. However, although it has not yet been experimentally verified, it is known that differences in the alkyl chain length affect the biodegradability of PBADs. In this study, we synthesized PBADs with alkylene diacid units, with the number of methylene chains ranging from 11 to 14. We subsequently investigated the relationship between their biodegradability via clear-zone formation and BOD-biodegradation testing and their physical properties, including their structural characteristics, using instrumental analysis. Although the monomers 1,4-butanediol (BD) and α,ω-dicarboxylic acids (DCA) exhibited good biochemical oxygen demand (BOD)-biodegradability, PBADs did not, indicating that PBADs with 11–14 methylene chains do not readily degrade in natural environments.