In recent years, biodegradable polymers have received more and more attention because of their potential impact upon the plastic waste management. Aliphatic polyesters are among the most promising compounds for biodegradable materials. The enzymatic degradation of a solid polymer is influenced by its crystallinity, its chemical structure and its molar mass and it is interesting to explore the structure-property relationships with respect to their biodegradability. A series of high molar mass poly(butylenesuccinate-co-butylenesebacate)s, P(BSu-co-BSe)s, were synthesized by melt polycondensation from 1,4-butanediol and dimethylesters of succinic and sebacic acids. Good filmability was achieved for all the polyesters. The structure and physical properties of the polyesters were analysed by 1H-NMR, SEC, DSC, X-ray and Viscometry. Filmed samples were subjected to enzymatic attack by lipase from Rhizopus Arrhizus or by lipase from Mucor Miehei and the relative normalised weight loss rates were compared. The results indicate that molar mass values show no significant influence on the biodegradation degree for the polyesters films investigated. The independence of biodegradation degree from variations in molar mass could indicate that the lipase used are endo-type enzymes that randomly break down ester bonds in the polymer chain. Undoubtedly, changes in the degree of crystallinity affect polyesters biodegradation but polymer chain structure appears to be a major factor that strongly influences the activity of the lipase from Rhizopus Arrhizus and from Mucor Miehei in P(BSu-co-BSe) copolymers.
SYNTHESIS, CHARACTERIZATION AND ENZYMATIC DEGRADATION OF ALIPHATIC COPOLYESTERS
Paola Rizzarelli;
2001
Abstract
In recent years, biodegradable polymers have received more and more attention because of their potential impact upon the plastic waste management. Aliphatic polyesters are among the most promising compounds for biodegradable materials. The enzymatic degradation of a solid polymer is influenced by its crystallinity, its chemical structure and its molar mass and it is interesting to explore the structure-property relationships with respect to their biodegradability. A series of high molar mass poly(butylenesuccinate-co-butylenesebacate)s, P(BSu-co-BSe)s, were synthesized by melt polycondensation from 1,4-butanediol and dimethylesters of succinic and sebacic acids. Good filmability was achieved for all the polyesters. The structure and physical properties of the polyesters were analysed by 1H-NMR, SEC, DSC, X-ray and Viscometry. Filmed samples were subjected to enzymatic attack by lipase from Rhizopus Arrhizus or by lipase from Mucor Miehei and the relative normalised weight loss rates were compared. The results indicate that molar mass values show no significant influence on the biodegradation degree for the polyesters films investigated. The independence of biodegradation degree from variations in molar mass could indicate that the lipase used are endo-type enzymes that randomly break down ester bonds in the polymer chain. Undoubtedly, changes in the degree of crystallinity affect polyesters biodegradation but polymer chain structure appears to be a major factor that strongly influences the activity of the lipase from Rhizopus Arrhizus and from Mucor Miehei in P(BSu-co-BSe) copolymers.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
