Highly Toughened and Transparent Biobased Epoxy Composites Reinforced with Cellulose Nanofibrils

Abstract

Biobased nanofillers, such as cellulose nanofibrils (CNFs), have been widely used as reinforcing fillers for various polymers due to their high mechanical properties and potential for sustainable production. In this study, CNF-based composites with a commercial biobased epoxy resin were prepared and characterized to determine the morphology, mechanical, thermal, and barrier properties. The addition of 18–23 wt % of CNFs to epoxy significantly increased the modulus, strength and strain of the resulting composites. The addition of fibrils led to an overall increase in strain energy density or modulus of toughness by almost 184 times for the composites compared to the neat epoxy. The addition of CNFs did not affect the high thermal stability of epoxy. The presence of nanofibrils had a strong reinforcing effect in both glassy and glass transition region of the composites. A significant decrease in intensity in tan δ peak for the epoxy matrix occurred with the addition of CNFs, indicating a high interaction between fibrils and epoxy during the phase transition. The presence of highly crystalline and high aspect ratio CNFs (23 wt %) decreased the water vapour permeability of the neat epoxy resin by more than 50%.

Recent Research Progress on Lignin-Derived Resins for Natural Fiber Composite Applications

“…Due to the thermostability and adhesive properties, the lignin-based resin has been suggested for fiber composite applications [ 31 , 34 , 35 ]. Several researchers have reported the lignin-based resin namely, hemp-epoxy [ 144 ], lignin/poly(ethylene oxide) [ 31 , 145 ], lignin/PVA [ 34 , 35 ], DL/epoxy [ 146 ], lignin/phenol formaldehyde [ 40 , 147 ], and fiber-reinforced composites [ 148 ]. Lignin-based resins have been used in broad applications such as sports equipment, tennis racquets, airplane, boats, and construction components for buildings due to their lightweight, high specific modulus and strength.…”

Promising Mechanical, Thermal, and Ballistic Properties of Novel Epoxy Composites Reinforced with Cyperus malaccensis Sedge Fiber

“…In particular, these composites are being considered for ballistic armors [ 27 , 28 , 29 , 30 ]. More recently, several researchers have been investigating the NLF waste as a source of nanocrystalline cellulose (NCC) [ 31 , 32 , 33 , 34 , 35 , 36 ], a strong nanomaterial, which can be used to produce several important products, such as nanocomposites, ion exchange membranes, films for electronics devices, and others [ 36 ].…”

Curing and thermal properties of tannin-based epoxy and its blends with commercial epoxy resin

“…There have been many literature reports about modification of epoxy resin using various types of bio-based materials, for examples, clay [5], lignin [6], plant seed oils [7], Eugenol [8], vanillin [9], plant waste filler [10], cellulose nanofibrils [11] and others. The use of natural materials (mainly bio-phenolic types) in epoxy technologies providing similar properties to those of synthetics materials such as modulus, curing and mechanical strength is still a highly important challenge.…”