Biodegradation of a sugar branched polymer consisting of sugar, fatty acid, and poly(vinyl alcohol)

We have examined synthesis of sugar branched polymer as a biodegradable material by utilizing natural substances. Biodegradation of a poly(vinyl alcohol) (PV-OH) having sugars and fatty acids was observed by a biochemical oxygen demand (BOD) tester using the oxygen consumption method. PV-OH is known as a biodegradable polymer by PV-OH assimilating microbes that are not distributed widely. In this paper, the sugar branched polymers were degraded depending upon the molecular weights, and the polymer having a molecular weight (M-n) of 3600 was degraded at 70-80% within 28 days by a soil or an activated sludge without addition of PV-OH assimilating microbes. This is because the proportion of PV-OH main chain in the molecular weight of the polymer is low. PV-OH with low molecular weight can be degraded without PV-OH assimilating microbes. These results indicate that the polymer is completely biodegradable and may have application as a new type of water-soluble material.