Mechanical Properties of Bio-Composites Based on Epoxy Resin and Nanocellulose Fibres

Abstract

The aim of our research was to investigate the effect of a small nanocellulose (NC) addition on an improvement of the mechanical properties of epoxy composites. A procedure of chemical extraction from pressed lignin was used to obtain nanocellulose fibers. The presence of nanoparticles in the cellulose pulp was confirmed by FTIR/ATR spectra as well as measurement of nanocellulose particle size using a Zetasizer analyzer. Epoxy composites with NC contents from 0.5% to 1.5% w/w were prepared. The obtained composites were subjected to strength tests, such as impact strength (IS) and resistance to three-point bending with a determination of critical stress intensity factor (Kc). The impact strength of nanocellulose composites doubled in comparison to the unmodified epoxy resin (EP 0). Moreover, Kc was increased by approximately 50% and 70% for the 1.5 and 0.5% w/w NC, respectively. The maximum value of stress at break was achieved at 1% NC concentration in EP and it was 15% higher than that for unmodified epoxy resin. The highest value of destruction energy was characterized by the composition with 0.5% NC and corresponds to the increase of 102% in comparison with EP 0. Based on the analysis of the results it was noted that satisfactory improvement of the mechanical properties of the composite was achieved with a very small addition of nanofiller while other research indicates the need to add much more nanocellulose. It is also expected that this kind of use of raw materials will allow increasing the economic efficiency of the nanocomposite preparation process. Moreover, nanocomposites obtained in this way can be applied as elements of machines or as a modified epoxy matrix for sandwich composites, enabling production of the structure material with reduced weight but improved mechanical properties.

Disposable Food Packaging and Serving Materials—Trends and Biodegradability

“…Cellulose is the most abundant polymer in the natural environment, and can be obtained from rice, wood, cotton, plant biomass, algae, and specific strains of bacteria [ 71 ]. It is a linear homopolymer, comprised of glucose units connected by β-(1→4) glycosidic bond.…”

Finite element analysis and experimental approaches of mono and hybrid nanocellulosic composites under tensile test

“…Even though nanocellulosic fibres and nanoparticles obtained from plants have benefits, their main limitation is related to the hydrophilic nature of cellulose [7]. In order to reduce the hydrophilicity of the nanocellulosic fibres and particles, these nanocellulosic fibres and particles are chemically modified in order to make them compatible with the hydrophobic matrices [7]. In order to reduce the aforementioned incompatibility, the reinforcement surface can be chemically modified [7,8].…”

“…In order to reduce the hydrophilicity of the nanocellulosic fibres and particles, these nanocellulosic fibres and particles are chemically modified in order to make them compatible with the hydrophobic matrices [7]. In order to reduce the aforementioned incompatibility, the reinforcement surface can be chemically modified [7,8]. Chemical treatments increase interfacial adhesion with hydrophobic matrices such as epoxy and decreases water absorption.…”

“…Chemical treatments increase interfacial adhesion with hydrophobic matrices such as epoxy and decreases water absorption. Among the reported chemical methods, mercerization, silanization, oxidation, esterification, grafting of branched/ hyperbranched polymers stand out [7][8][9][10].…”

Role of cellulose nanocrystals in epoxy-based nanocomposites: mechanical properties, morphology and thermal behavior

“…Roszowska-Jarosz et al [15] describe the production of epoxy/ CNC nanocomposites by adding a suspension of CNCs and acetone in the quantities of 0.5%, 1% and 1.5%wt in epoxy resin, for which they obtained superior values for impact resistance and flexural strength. Nissilä et al [16] produced nanocomposites by impregnating cellulose nanofibers (CNF) in bio-epoxy resin.…”