Micromechanics of TEMPO-oxidized fibrillated cellulose composites

M Bulota, S Tanpichai, M Hughes, SJ Eichhorn

Research output: Contribution to journalArticle (Academic Journal)peer-review

52 Citations (Scopus)

Abstract

Composites of poly(lactic) acid (PLA) reinforced with TEMPO-oxidized fibrillated cellulose (TOFC) were prepared to 15, 20, 25, and 30% fiber weight fractions. To aid dispersion and to improve stress transfer, we acetylated the TOFC prior to the fabrication of TOFC-PLA composite films. Raman spectroscopy was employed to study the deformation micromechanics in these systems. Microtensile specimens were prepared from the films and deformed in tension with Raman spectra being collected simultaneously during deformation. A shift in a Raman peak initially located at ∼1095 cm -1 , assigned to C-O-C stretching of the cellulose backbone, was observed upon deformation, indicating stress transfer from the matrix to the TOFC reinforcement. The highest band shift rate, with respect to strain, was observed in composites having a 30% weight fraction of TOFC. These composites also displayed a significantly higher strain to failure compared to pure acetylated TOFC film, and to the composites having lower weight fractions of TOFC. The stress-transfer processes that occur in microfibrillated cellulose composites are discussed with reference to the micromechanical data presented. It is shown that these TOFC-based composite materials are progressively dominated by the mechanics of the networks, and a shear-lag type stress transfer between fibers. © 2011 American Chemical Society.
Original languageUndefined/Unknown
Pages (from-to)331-337
Number of pages7
JournalACS Applied Materials and Interfaces
Volume4
DOIs
Publication statusPublished - 1 Jan 2012

Cite this