Nanocellulose: a new ageless bionanomaterial

Production and modification of nanofibrillated cellulose using various mechanical processes: A review

With increasing environmental and ecological concerns due to the use of petroleum-based chemicals and products, the synthesis of fine chemicals and functional materials from natural resources is of great public value. Nanocellulose may prove to be one of the most promising green materials of modern times due to its intrinsic properties, renewability, and abundance. In this review, we present nanocellulose-based materials from sourcing, synthesis, and surface modification of nanocellulose, to materials formation and applications. Nanocellulose can be sourced from biomass, plants, or bacteria, relying on fairly simple, scalable, and efficient isolation techniques. Mechanical, chemical, and enzymatic treatments, or a combination of these, can be used to extract nanocellulose from natural sources. The properties of nanocellulose are dependent on the source, the isolation technique, and potential subsequent surface transformations. Nanocellulose surface modification techniques are typically used to introduce e...

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Nanocellulose, a Versatile Green Platform: From Biosources to Materials and Their Applications

This review article describes the recent developments of natural fiber reinforced polypropylene (PP) composites. Natural fibers are low-cost, recyclable, and eco-friendly materials. Due to eco-friendly and bio-degradability characteristics of these natural fibers, they are considered as strong candidates to replace the conventional glass and carbon fibers. The chemical, mechanical, and physical properties of natural fibers have distinct properties; depending upon the cellulosic content of the fibers which varies from fiber to fiber. The mechanical properties of composites are influenced mainly by the adhesion between matrix and fibers. Chemical and physical modification methods were incorporated to improve the fiber—matrix adhesion resulting in the enhancement of mechanical properties of the composites. The most important natural fibers are jute, flax, and coir and their novel processing technics to develop natural fiber reinforced composites are also described.

Recent Development in Natural Fiber Reinforced Polypropylene Composites

The main goal of this article is to provide an overview of recent research in the area of cellulose nanomaterial production from different sources. Due to their abundance, renewability, high strength and stiffness, eco-friendliness and low weight, numerous studies have been reported on the isolation of cellulose nanomaterials from different cellulosic sources and their use in high-performance applications. This report covers an introduction to the definition of nanocellulose as well as the methods used for isolation of nanomaterials (including nanocrystals and nanofibers, CNCs and CNFs, respectively) from various sources. The web-like network structure (CNFs) can be extracted from natural sources using mechanical processes, which include high-pressure homogenization, grinding and refining treatments. Also, rod-like CNCs can be isolated from sources such as wood, plant fibers, agricultural and industrial bioresidues, tunicates and bacterial cellulose using an acid hydrolysis process. Following this, the article focuses on the characterization methods, material properties and structures. Encyclopedic characteristics of CNFs and CNCs obtained from different source materials and/or studies are also included. The current report is a comprehensive review of the literature regarding nanocellulose isolation and demonstrates the potential of cellulose nanomaterials for a wide range of high-tech applications.

Different preparation methods and properties of nanostructured cellulose from various natural resources and residues: a review

Nanocellulose was prepared by acid hydrolysis of microcrystalline cellulose (MCC) at different hydrobromic acid (HBr) concentrations. Polyvinyl alcohol (PVA) composite films were prepared by the reinforcement of nanocellulose into a PVA matrix at different filler loading levels and subsequent film casting. Chemical characterization of nanocelluloses was performed for the analysis of crystallinity (Xc), degree of polymerization (DP), and molecular weight (Mw). The mechanical and thermal properties of the nanocellulose reinforced PVA films were also measured for tensile strength and thermogravimetric analysis (TGA). The acid hydrolysis decreased steadily the DP and Mw of MCC. The crystallinity of MCC with 1.5 M and 2.5 M HBr showed a significant increase due to the degradation of amorphous domains in cellulose. Higher crystalline cellulose showed the higher thermal stability than MCC. From X-ray diffraction (XRD) analysis, nanocellulose samples showed the higher peak intensity than MCC cases. Reduction of MCC particle by acid hydrolysis was clearly observed from scanning electron microscope (SEM) images. The tensile and thermal properties of PVA composite films were significantly improved with the increase of the nanocellulose loading.

Nanocellulose reinforced PVA composite films: Effects of acid treatment and filler loading

Preparation of cellulose nanofibrils by high-pressure homogenizer and cellulose-based composite films

The effects of chemical modification (silane coupling) and filler loading on the fundamental properties of the bamboo fiber (BF) filled polypropylene (PP) bio-composites were investigated in this study. Mechanical properties of the PP/ BF composites, such as the tensile strength, flexural strength, and impact strength decreased as BF loading increased. However, the tensile modulus, flexural modulus, and water absorption were increased by the increase of the BF loading. The addition of aminopropyltrimethoxysilane (AS) and tetramethoxy orthosilicate (TMOS) after the alkali pretreatment for the BF increased all the tensile, flexural, impact strength, and water desorption of the resultant composites, resulting from the improved adhesion between the BF and PP matrix. This tendency was more obvious with the increase of the BF loading. The melting temperature, melting enthalpy, crystallization enthalpy, and crystallinity were decreased by the increase of BF loading and the AS and TMOS treatments. One the other h...

Influence of Chemical Modification and Filler Loading on Fundamental Properties of Bamboo Fibers Reinforced Polypropylene Composites

Thermal behavior of liquefied wood polymer composites (LWPC)

Bamboo fiber (BF) filled polypropylene (PP) composites were manufactured by melt compounding and injection molding. The incorporation of BF to neat PP increased the decomposition temperatures of the composites compared to neat PP. The loading of BF to PP decreased the melting temperature, melting enthalpy, crystallization enthalpy, crystallization temperature, and crystallinity. Tensile modulus, impact resistance, and creep improved as BF loading increased. However, tensile strength and water desorption were decreased by the increase of BF loading. The addition of maleated polypropylene (MAPP) as a coupling agent increased the tensile strength and modulus. The melting enthalpy and crystallization enthalpy were decreased by the addition of MAPP. The loading of MAPP also improved the water desorption, impact resistance, and bamboo fiber dispersion into neat PP matrix, while lowering creep. There was no significant effect of MAPP on the thermal deformation and melting temperature of the composites. The melti...

In-Aeh Kang

Papers

Nanocellulose reinforced PVA composite films: Effects of acid treatment and filler loading

Preparation of cellulose nanofibrils by high-pressure homogenizer and cellulose-based composite films

Influence of Chemical Modification and Filler Loading on Fundamental Properties of Bamboo Fibers Reinforced Polypropylene Composites

Thermal behavior of liquefied wood polymer composites (LWPC)

Effects of Filler and Coupling Agent on the Properties of Bamboo Fiber-Reinforced Polypropylene Composites