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A novel diester monomer synthesized from 4-hydroxybenzoic acid, a compound which can be derived from lignin, was used to obtain aliphatic-aromatic copolyesters (P1-P4) by melt polymerization with 1,4-cyclohexanedimethanol, and either 1,4-butanedioic acid, 1,6-hexanedioic acid, 1,8-octanedioic acid, or 1,12-dodecanedioic acid as aliphatic diacid. Structure-property relations for the copolyesters were established using FTIR and 1H NMR spectroscopy, gel permeation chromatography, differential scanning calorimetry, thermogravimetric analysis, dynamic mechanical analysis and tensile testing. The weight-average molecular weight (Mw) of the samples ranged from 41,400 to 48,300 g/mol. As the spacer length in the aliphatic diacid was increased, the glass transition temperature (Tg) decreased from 90 to 51 degrees C, the melting point (Tm) from 175 to 147 degrees C, the tensile modulus from 1800 to 980 MPa, and the yield strength from 76 to 54 MPa, while the elongation at break increased from 270 to 320%. The thermal stability of the copolyesters also decreased for longer aliphatic diacid spacers. The copolyester derived from 1,12-dodecanedioic acid displayed the highest degradation rate in artificial soil, with 4.4% degradation after 30 weeks, and low ecotoxicity in an earthworm viability test. These findings contribute to understanding structure-property relationships and the environmental impact of aliphatic-aromatic copolyesters as potential sustainable materials.

来源平台：JOURNAL OF POLYMERS AND THE ENVIRONMENT