Morphology and mechanical properties of poly(ethylene brassylate)/cellulose nanocrystal composites

Amaia Butron; Olatz Llorente; Jorge Fernandez; Emilio Meaurio; Jose-Ramon Sarasua

doi:10.1016/j.carbpol.2019.05.091

Morphology and mechanical properties of poly(ethylene brassylate)/cellulose nanocrystal composites

Carbohydr Polym. 2019 Oct 1:221:137-145. doi: 10.1016/j.carbpol.2019.05.091. Epub 2019 Jun 1.

Authors

Amaia Butron¹, Olatz Llorente², Jorge Fernandez³, Emilio Meaurio², Jose-Ramon Sarasua²

Affiliations

¹ Tecnalia, Sede Azpeitia, Área Anardi 5, E-20730 Azpeitia, Gipuzkoa, Spain; Department of Mining-Metallurgy Engineering and Materials Science, POLYMAT, University of The Basque Country (UPV/EHU), School of Engineering, Plaza Ingeniero Torres Quevedo s/n, 48013 Bilbao, Spain. Electronic address: amaia.butron@tecnalia.com.
² Department of Mining-Metallurgy Engineering and Materials Science, POLYMAT, University of The Basque Country (UPV/EHU), School of Engineering, Plaza Ingeniero Torres Quevedo s/n, 48013 Bilbao, Spain.
³ Polimerbio, Paseo Mikeletegi 83, 20009 Donostia-San Sebastian, Spain.

PMID: 31227152
DOI: 10.1016/j.carbpol.2019.05.091

Abstract

Poly(ethylene brassylate), a novel inexpensive biodegradable polyester, has been reinforced with cellulose nanocrystals (CNCs) with the aim of improving its thermal stability and mechanical properties. The composites have been characterized through calorimetry, tensile tests, thermogravimetry and electron microscopy. The addition of small amounts of CNCs improves both the stiffness and the ductility of the composites, suggesting the existence of some compatibilizing effect. Adding large CNC amounts increases the Young modulus (e.g., 150% for 50 wt% CNCs), but now the material shows brittle behavior. Degradation of the CNCs starts at lower temperature suggesting mutual reactivity. The SEM analysis of the composites with ductile behavior reveals the formation of a percolating network crossing through the interconnected domains that conform a PEB-rich continuous phase. Processing consisting on reinforcement dispersion by sonication followed by melt processing results in composites in which the improvement of mechanical properties does not involve any trade-off.

Keywords: Cellulose nanocrystals (CNC); Mechanical properties; Nanocomposites; Poly(ethylene brassylate) (PEB).