LDPE-based composites reinforced with surface modified cellulose fibres: 3D morphological and morphometrical analyses to understand the improved mechanical performance

• Published in: European polymer journal 2019-08, Vol.117, p.105-113
• Main Authors: Ferreira, F.V., Trindade, G.N., Lona, L.M.F., Bernardes, J.S., Gouveia, R.F.
• Format: Article
• Language: English
• Subjects: Bagasse; Cellulose; Cellulose fibers; Composite materials; CT analysis; Dispersion; Fillers; Hexamethyldisiloxane; Imaging techniques; Low density polyethylenes; Mechanical properties; Microstructural analysis; Microstructure; Natural fibers; Organic chemistry; Photomicrographs; Polymer composites; Polymer matrix composites; Polymers; Sugarcane; Surface modification; Synergistic effect; X ray microtomography
• ISSN: 0014-3057; 1873-1945
• DOI: 10.1016/j.eurpolymj.2019.05.005

[Display omitted] •Cellulose from sugarcane bagasse was used as filler in low-density polyethylene (LDPE).•Hydrophobic cellulose surface was successfully prepared by silylation reaction.•X-ray microtomography was used to analyse the filler dispersion in the LDPE.•3D morphological and morphometrical analyses were used to investigate the improved mechanical performance. In this study, we reported the use of X-ray microtomography (µCT) as a new analytical tool to investigate better the dispersion of natural filler in the polymer matrix. The pre-treated sugarcane bagasse (SCB), richer in cellulose, was first functionalised by hexamethyldisiloxane (HMDS) and then added (10, 20 and 30 wt% filler) to low-density polyethylene (LDPE) by melt mixing. The microstructure organization of the cellulose in the composites was studied using 3D and 2D µCT images, where it was possible to obtain an in-depth morphological and morphometric analysis. Thus, the synergistic effect of the filler on the mechanical properties of the polymer matrix as a function of surface chemistry was well clarified without the need of a large number of micrographs as is required to show the quality of dispersion using conventional imaging techniques. The characterisation method reported here is an easy, non-destructive and powerful way to characterise the cellulose fibres dispersion in LDPE-based composites and it can be applied to other fillers and polymer matrices.