BIONANOCOMPOSITES OF FURANDICARBOXYLATE-BASED COPOLYMERS: CONTRIBUTION OF THE INTERPHASES TO THE MECHANICAL, BARRIER AND BIODEGRADATION PROPERTIES

Abstract

Bio-based and biodegradable polymers (biopolymers) are now seen as the most sustainable alternatives to traditional petroleum polymers as they address the current environmental concerns in terms of the depletion of fossil resources, the ever-growing plastic pollution and greenhouse gas emissions. Furandicarboxylate-based polyesters have emerged as new interesting bio-based polymers, alternative to terephthalate-based polyesters. All the furandicarboxylate-based polyesters exhibit better mechanical, thermal, and gas barrier properties with respect to the homologous terephthalic-based polyesters. Biodegradation of this family of polyesters can be improved by introducing additional aliphatic sub-units, for example by copolymerization. But this chemical modification worsens the mechanical and barrier properties of the material. A technique useful to counterbalance the negative effects of the aliphatic sequences on the mechanical and barrier properties is the incorporation of nano-sized fillers within the polymer matrix, to obtain nanocomposites. This study is focused on the preparation of promising bio-based and biodegradable nanocomposites of furandicarboxylate-based copolymers, with attractive performance (good mechanical, barrier and biodegradation properties) for potentially wide applications. Owing to their nanoscale dimensions, nanofillers possess a large surface area for a given volume and, consequently, the polymer/nanofiller interphase represents a significant volume fraction even at low filler concentrations. In this regard, the major challenges to develop nanocomposites for specific advanced applications is the capacity to understand, tailor and optimize not only the size and shape of the nanofillers, but also the structure and properties of the interphases between the polymer and nanofiller. The present study contributes also to a better knowledge and understanding of the role that the nano-sized interphases, at the amorphous/crystal and at the amorphous/filler boundaries can have on the mechanical, and barrier properties, and biodegradation behavior of the resultant nanocomposites. Various nanofillers, eventually properly chemically modified to improve the matrix/nanofiller interaction, will be used for the preparation of furandicarboxylate-based copolymers nanocomposites. Thermal, mechanical, viscoelastic, morphological, barrier, and biodegradation properties will be evaluated. Modelling techniques will be adopted for the estimation of some interphase properties (e.g. elastic modulus). Thus, the further aim of the present study will be to identify how the various macroscopic properties are differently influenced by distinct nanofiller parameters such as amount, class, size/shape, and strength of the polymer-filler interaction.

Team di ricerca UNIBO

Micaela Vannini, Annamaria Celli, Laura Sisti

Partner di progetto

Università di Pisa, CNR