Combination of cellulose nanofibers and chain‐end‐functionalized polyethylene and their applications in nanocomposites

Abstract

In this study, nanofiber cellulose (NFC) based on a 2,2,6,6-tetramethylpiperidine-1-oxyl radical oxidization method was successfully combined with chain-end-functionalized polyethylene containing alkoxysilane via silanization. Fourier transform infrared spectroscopy, transmission electron microscopy, contact angle measurements, Molau tests, and X-ray photoelectron spectroscopy analyses provided further evidence for the effectiveness of the surface modifications. The hydrophilic surface characteristics of NFC were changed to apparently hydrophobic for the modified nanofiber cellulose (M-NFC). Then, the linear low-density polyethylene (LLDPE)/M-NFC nanocomposite was prepared, and the mechanical properties, thermal properties, and crystallization properties of the LLDPE-M-NFC were investigated by tensile testing, thermogravimetric analysis, differential scanning calorimetry, and dynamic mechanical analysis. The results show that after modification, the thermal stability of NFC was enhanced. The interface between M-NFC and the matrix was good. The tensile strength and Young's modulus values of the nanocomposites were enhanced compared with those of LLDPE; in particular, the tensile strength and Young's modulus of the blend with 5 wt % M-NFC increased by 56 and 106%, respectively. The storage modulus of the nanocomposites was enhanced obviously over a wide temperature range. The addition of a small amount of M-NFC had slight effects on the crystallinity and melting temperature of LLDPE. V C 2017 Wiley Periodicals, Inc. J.Appl. Polym. Sci. 2017, 134, 45387.

Recent Advances in Nanocellulose Composites with Polymers: A Guide for Choosing Partners and How to Incorporate Them

“…The silane coupling reaction was also utilized for the modification of TOCN by PE and the subsequent preparation of LLDPE/TOCN nanocomposite [ 198 ]. In this case, the PE was end-functionalized with alkoxysilane that reacted with TOCN in toluene at 110 °C.…”

Nanocomposites of low-density polyethylene and nanocellulose: An alternative route using bleached cellulose nanofibers gel suspension

“…41 The increase in stiffness was expected based on the CNF stiffness and demonstrates the ability of the matrix to transfer low elastic strains through the interface. 42 Increasing the CNF content also caused a significant decrease in strain at break due to the associated increase in stiffness produced by the CNF, ranging from 169% for the LDPE sample, to 160%, 157% and 146% for the LDPE_0.5%CNF, LDPE_1.0%CNF and LDPE_2.0% CNF samples, respectively.…”

Nanosystems in Edible Coatings: A Novel Strategy for Food Preservation

“…Due to their origin and properties, proteins, lipids, and polysaccharides have been used in the preparation of edible coatings. These components have also been prepared by mixing different proportions of each one to improve their barrier properties to gases, since hydrocolloids are characterized by providing a good barrier to oxygen, but a poor one to water vapor, though this can be enhanced by adding a lipid substance [ 11 , 60 ]. At present, due to the demand of minimally-processed—“healthful”—products, there is a constant challenge to develop new and more efficient edible coatings.…”

“…A very attractive strategy is to elaborate coatings that incorporate nanosystems mixed with organic and inorganic substances that produce nanocomposites. These mixtures represent a recent option for improving the properties of edible coatings, since they permit better mechanical resistance, transparency, controlled release, and more effective gas barrier properties [ 11 , 60 ]. The most widely-used inorganic components for modifying the properties of edible coatings include montmorillonite (MMT), nano-SiOx, nano-TiO 2 , and nano-ZnO, as well as silver nanoparticles, though it is important to note that the latter can only be used to coat whole fruits and vegetables [ 61 ].…”

“…Another aspect considered is antioxidant capacity, which reduces the rate of reactions and enzymatic activity of, for example, polyphenol oxidases, peroxidases, and lipoxygenases. The use of nanosystems has thus propitiated exploration of ways to control the release of elements into the environment, by acting as a barrier in conjunction with the polymer matrix into which they are incorporated [ 9 , 10 , 11 ]. Nanosystems have distinct morphologies that modify the characteristics of edible coatings in different ways [ 12 ].…”