Abstract
Cellulose nanofibrils (CNFs) are high aspect ratio, natural nanomaterials with high mechanical strength-to-weight ratio and promising reinforcing dopants in polymer nanocomposites. In this study, we used CNFs and oxidized CNFs (TOCNFs), prepared by a 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-mediated oxidation process, as reinforcing agents in poly(vinylidene fluoride) (PVDF). Using high-shear mixing and doctor blade casting, we prepared free-standing composite films loaded with up to 5 wt % cellulose nanofibrils. For our processing conditions, all CNF/PVDF and TOCNF/PVDF films remain in the same crystalline phase as neat PVDF. In the as-prepared composites, the addition of CNFs on average increases crystallinity, whereas TOCNFs reduces it. Further, addition of CNFs and TOCNFs influences properties such as surface wettability, as well as thermal and mechanical behaviors of the composites. When compared to neat PVDF, the thermal stability of the composites is reduced. With regards to bulk mechanical properties, addition of CNFs or TOCNFs, generally reduces the tensile properties of the composites. However, a small increase (~18%) in the tensile modulus was observed for the 1 wt % TOCNF/PVDF composite. Surface mechanical properties, obtained from nanoindentation, show that the composites have enhanced performance. For the 5 wt % CNF/PVDF composite, the reduced modulus and hardness increased by ~52% and ~22%, whereas for the 3 wt % TOCNF/PVDF sample, the increase was ~23% and ~25% respectively.
Highlights
The behavior of composite materials is strongly influenced by the physical and chemical properties of its constituents as well as the interfacial interactions between them
Our results suggest that certain properties of the composites, such as surface wettability, thermal and mechanical responses, can be altered through incorporation of these dopants
Thermal degradation of TOCNF/poly(vinylidene fluoride) (PVDF) composites occurs at lower temperatures than those of the Cellulose nanofibrils (CNFs)/PVDF composites due to the reduced thermal stability of TOCNFs
Summary
The behavior of composite materials is strongly influenced by the physical and chemical properties of its constituents as well as the interfacial interactions between them. Reinforcing fillers include clays [2,3], carbon nanomaterials such as carbon nanofibers [4] and carbon nanotubes [5], which have been widely studied in various polymer systems and composites [6]. Has made recommendations for reducing worker exposure to carbon nanotubes and nanofibers, as well as respiratory screening for workers exposed to 1 μg/m3 (8 hour time weighted average) [8,9] Certain nanoclays, such as Cloisite Na+ , Cloisite 93A and Cloisite 30B, have been reported to induce significant cell death, genotoxic effects and morphological alterations in human cell lines [10]. One of these additives is cellulose, which is the most abundant organic polymer on Earth and is the basic structural building block of plants and biofilms [11]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
