Nowadays, literature shows a great interest in developing new polyesters, with the desired final properties according to the possible applications, by combining different monomers available from petrolchemical industry or, more recently, from biomass. 1,4-cylohexanedicarboxylic acid (or the corresponding diester) is a very interesting monomer, relatively less studied and characterized, instead, by notable properties, such as a potential origin from renewable resources. The 1,4-cyclohexylene unit is structurally rigid and can induce relative stiffness in the macromolecular chain in which it is inserted and, then, improve the poor physical and mechanical properties typical of the aliphatic polyesters. Moreover, it has been found that the final properties of the polyesters containing 1,4-cyclohexane dicarboxylate units strongly depend on the stereochemistry of the rings. Indeed, a high percentage of the trans isomer in the cycloaliphatic units favours a high level of crystallinity and relatively high melting temperature. On the other hand, a low trans content induces low crystallinity up to a fully amorphous phase. Therefore, we have combined this monomer with diols and other diacids, for example with 1,4-butanediol, dimethyl adipate or 1,12-dodecanedioic acid, to obtain novel copolyesters. Interesting correlation between molecular structure and thermo-mechanical properties have been found, indicating that the final properties can be easily modulated by changing the length of the –(CH2)- sequences, the isomeric ratio of the 1,4-cyclohexylene units, and the molar composition of the copolyesters. Moreover, biodegradation tests have been carried out in an aqueous mineral nutrient medium inoculated by micro-organisms resulting from active ground or compost. Some copolyesters present a very high biodegradation rate, mainly connected to a low level of crystallinity. Therefore, the use of the 1,4-cycloaliphatic unit as building blocks for novel aliphatic polyesters can lead to optimum combinations of thermo-mechanical properties and biodegradability.
Celli A., Marchese P., Sullalti S., Berti C., Barbiroli G., Commereuc S. (2010). Novel eco-friendly aliphatic copolyesters: structure-property relationship and biodegradation behaviour. JOURNAL OF BIOTECHNOLOGY, 150S, 205-206 [10.1016/j.jbiotec.2010.09.014].
Novel eco-friendly aliphatic copolyesters: structure-property relationship and biodegradation behaviour
CELLI, ANNAMARIA;MARCHESE, PAOLA;SULLALTI, SIMONE;BERTI, CORRADO;BARBIROLI, GIANCARLO;
2010
Abstract
Nowadays, literature shows a great interest in developing new polyesters, with the desired final properties according to the possible applications, by combining different monomers available from petrolchemical industry or, more recently, from biomass. 1,4-cylohexanedicarboxylic acid (or the corresponding diester) is a very interesting monomer, relatively less studied and characterized, instead, by notable properties, such as a potential origin from renewable resources. The 1,4-cyclohexylene unit is structurally rigid and can induce relative stiffness in the macromolecular chain in which it is inserted and, then, improve the poor physical and mechanical properties typical of the aliphatic polyesters. Moreover, it has been found that the final properties of the polyesters containing 1,4-cyclohexane dicarboxylate units strongly depend on the stereochemistry of the rings. Indeed, a high percentage of the trans isomer in the cycloaliphatic units favours a high level of crystallinity and relatively high melting temperature. On the other hand, a low trans content induces low crystallinity up to a fully amorphous phase. Therefore, we have combined this monomer with diols and other diacids, for example with 1,4-butanediol, dimethyl adipate or 1,12-dodecanedioic acid, to obtain novel copolyesters. Interesting correlation between molecular structure and thermo-mechanical properties have been found, indicating that the final properties can be easily modulated by changing the length of the –(CH2)- sequences, the isomeric ratio of the 1,4-cyclohexylene units, and the molar composition of the copolyesters. Moreover, biodegradation tests have been carried out in an aqueous mineral nutrient medium inoculated by micro-organisms resulting from active ground or compost. Some copolyesters present a very high biodegradation rate, mainly connected to a low level of crystallinity. Therefore, the use of the 1,4-cycloaliphatic unit as building blocks for novel aliphatic polyesters can lead to optimum combinations of thermo-mechanical properties and biodegradability.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
