Enhancement of crystallization and mechanical properties of poly(ethylene adipate-co-terephthalate) by in-situ preparation of nanocomposites with cellulose nanofibers

초록

Poly (ethylene adipate-co-terephthalate) (PEAT) is a copolyester whose properties can be modulated by adjusting the ratio of ethylene adipate (EA) and ethylene terephthalate (ET) units. PET segments provide crystallinity and mechanical strength, while PEA segments contribute to flexibility and potential biodegradability. However, its slow crystallization rate has hindered industrial-scale production and processing. This study investigates the enhancement of crystallization behavior and mechanical properties of PEAT nanocomposites reinforced with TEMPO-oxidized cellulose nanofibers (TCNF) through the in-situ preparation where the monomers were polymerized in the presence of the well-dispersed nanofillers. TCNF, with their high surface area and excellent specific strength, were uniformly dispersed in the PEAT matrix during polymerization, resulting in nanocomposites with improved structural integrity. The presence of TCNF significantly accelerated crystallization rates and improved crystallinity levels. Moreover, small loadings enhanced the overall thermal resistance of the nanocomposites. Mechanical testing revealed a notable 1.3-fold increase in tensile modulus. Rheological analysis showed that the nanocomposites maintained a viscous-dominant behavior, with increase in elasticity at low frequencies due to interactions between TCNF and the polymer chains. The synergetic effect of TCNF on crystallization behavior offers a promising route for developing high-performance biodegradable polyesters. © 2025 Elsevier Ltd

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