J a p a n SYNOPSIS A series of polyesters was synthesized by the bulk polycondensations of the respective combinations of three stereoisomeric 1,4 : 3,6-&anhydrohexitols [ 1,4 : 3,6-dianhydro-~-glucitol (l), 1,4 : 3,6-dianhydro-D-mannitol (2), and 1,4 : 3,6-dianhydro-~-iditol (3)] with succinyl dichloride (4a), glutaryl dichloride (4b), adipoyl dichloride (4c), and sebacoyl dichloride (4d). Biodegradability of these polyesters was investigated by three different methods, i.e., degradation in an activated sludge, soil burial degradation, and enzymatic degradation. Although polyesters (7b-7d) based on 3 and polyester 6a derived from 2 and 4a were crystalline and scarcely biodegraded, all the other amorphous polyesters were more or less biodegradable. Biodegradability of the polyesters was found to vary significantly depending on their molecular structures. Soil burial degradation of polyesters in the soil that was treated with antibiotics, together with electron scanning microscopic observation, showed that polyesters 5b and 5c prepared from 1 and 4b or 4c were degraded by both bacteria and filamentous fungi, whereas polyester 5d from 1 and 4d was degraded primarily by filamentous fungi.
SYNOPSISSix different polyesters (6a-6c and 7a-7c) were prepared by the bulk polycondensations of the respective combinations of 1,4:3,6-dianhydro-~-glucitol (3) and 1,4:3,6-dianhydro-D-mannitol(4) with succinyl dichloride (5a), glutaryl dichloride (5b), and adipoyl dichloride (5c) a t 140-180°C. Polyesters having number average molecular weights up to 2.6 X lo4 were obtained in high yields. Only polyester 7a based on 4 and 5a was partially crystalline, whereas all the other polyesters were amorphous. Thin films of these polyesters except that of 7a were spontaneously hydrolyzed in a neutral phosphate buffer solution a t 50"C, whereas they were reluctant to be hydrolyzed a t 27°C. The polyesters were more or less degraded at 27°C by treatment with an activated sludge or by prolonged burial in soil. 0 CCC 0887-624X/95/162813-08 as well as spontaneous hydrolytic degradation in a neutral phosphate buffer These polyesters were prepared by cationic ring-opening polymerization of bicyclic lactones, 6,g-dioxabicyclo[3.2.l]octan -7 -one and 2,6 -dioxabicyclo [2.2.2]octan-3-one, respectively.
J a p a n SYNOPSIS A series of polyesters was synthesized by the bulk polycondensations of the respective combinations of three stereoisomeric 1,4 : 3,6-&anhydrohexitols [ 1,4 : 3,6-dianhydro-~glucitol (l), 1,4 : 3,6-dianhydro-D-mannitol (2), and 1,4 : 3,6-dianhydro-~-iditol (3)] with succinyl dichloride (4a), glutaryl dichloride (4b), adipoyl dichloride (4c), and sebacoyl dichloride (4d). Biodegradability of these polyesters was investigated by three different methods, i.e., degradation in an activated sludge, soil burial degradation, and enzymatic degradation. Although polyesters (7b-7d) based on 3 and polyester 6a derived from 2 and 4a were crystalline and scarcely biodegraded, all the other amorphous polyesters were more or less biodegradable. Biodegradability of the polyesters was found to vary significantly depending on their molecular structures. Soil burial degradation of polyesters in the soil that was treated with antibiotics, together with electron scanning microscopic observation, showed that polyesters 5b and 5c prepared from 1 and 4b or 4c were degraded by both bacteria and filamentous fungi, whereas polyester 5d from 1 and 4d was degraded primarily by filamentous fungi.
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