Y. Davoudpour

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

Nanofibrillated cellulose from biomass has recently gained attention owing to their biodegradable nature, low density, high mechanical properties, economic value and renewability. Although they still suffer from two major drawbacks. The first challenge is the exploration of raw materials and its application in nanocomposites production. Second one is high energy consumption regarding the mechanical fibrillation. However, pretreatments before mechanical isolation can overcome this problem. Hydrophilic nature of nano-size cellulose fibers restricts good dispersion of these materials in hydrophobic polymers and therefore, leads to lower mechanical properties. Surface modification before or after mechanical defibrillation could be a solution for this problem. Additionally, drying affects the size of nanofibers and its properties which needs to study further. This review focuses on recent developments in pretreatments, nanofibrillated cellulose production and its application in nanopaper applications, coating additives, security papers, food packaging, and surface modifications and also for first time its drying.

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

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.

A review on chitosan-cellulose blends and nanocellulose reinforced chitosan biocomposites: Properties and their applications

Chitin is one of the most abundant natural polymers in world and it is used for the production of chitosan by deacetylation. Chitosan is antibacterial in nature, non-toxic, and biodegradable thus it can be used for the production of biodegradable film which is a green alternative to commercially available synthetic counterparts. However, their poor mechanical and thermal properties restricted its wide spread applications. Chitosan is highly compatible with other biopolymers thus its blending with cellulose and/or incorporation of nanofiber isolated from cellulose namely cellulose nanofiber and cellulose nanowhiskers are generally useful. Cellulosic fibers in nano scale are attractive reinforcement in chitosan to produce environmental friendly composite films with improved physical properties. Thus chitosan based composites have wide applicability and potential in the field of biomedical, packaging and water treatment. This review summarises properties and preparation procedure of chitosan-cellulose blends and nano size cellulose reinforcement in chitosan bionanocomposites for different applications.

Natural fiber reinforced poly(vinyl chloride) composites : a review.

Materials from renewable resources – also called biomaterials or ‘green’ materials – are presently gaining in importance worldwide. In these times of continuous increases in the price of crude oil and discussion of carbon dioxide (CO2) emissions, conventional plastics have reached a price level and a questionable image which promotes the search of alternatives. Natural fibers are a renewable natural resource and are biodegradable, which is an important characteristic for components that must be disposed of at the end of their useful life. They are recyclable and can be easily converted into thermal energy through combustion without leaving residue. In this study, we will discuss the natural fiber reinforced polyvinyl chloride composites, reinforcing effect, plasticization effect along with modification by coupling agents, properties, and applications based on composite materials. Also, the polyvinyl chloride-based composite materials with specific emphasis on effect of coupling agent, foamed polyvinyl chloride composites, and the effect of natural fiber reinforcement on its material properties will be reviewed. One of the best alternatives is natural fiber reinforced plastics composites. These are composites that are typically filled or reinforced with plant fibers, as well as plastics such as polyvinyl chloride or recently, even bioplastics.

Electrospun Cellulose Composite Nanofibers

This chapter deals with the structure, properties, and applications of electrospun-based cellulose composites. Extraction methods of cellulosic nanofibers from different sources are discussed in detail. Cellulose has the special advantage of high specific strength and sustainability, which make them ideal candidates for reinforcement in various polymeric matrices. Cellulose nanofibers find application in various fields, including construction, the automobile industry, and soil conservation. Cellulose, an eminent representative of nanomaterial obtained from various natural fibers, can be dissolved in various solvent systems, which are described in detail in this study. Thermoplastic-based electrospun cellulose nanocomposites and their applications are highlighted. This chapter describes current and future applications of electrospun cellulosic nanofibers in various fields.

15 – Mechanical properties of oil palm biocomposites enhanced with micro to nanobiofillers

In recent years, utilization of natural fibre as reinforced materials in polymer biocomposites has gained impetus. Research efforts are currently being harnessed in developing more sustainable products. Oil palm biomass contribute among the highest and most abundant wastes with high potential for energy and material resources. Oil palm consists only around 10% of oil, leaving another 90% as biomass wastes. The remainder consists of a huge amount of lignocellulosic materials in the form of fronds, trunks, empty fruit bunches, oil palm shell, palm pressed fibre, oil palm ash, and so forth. Biocomposites enhanced with biofiller have been used extensively in various fields because this filler behaves isotropically to the matrix. Several researchers have been worked on utilizing various oil palm biomasses as filler in polymer biocomposites ranging from micro- to nanosize. In producing high-performance biocomposites, mechanical properties would be mainly taken into consideration. The mechanical properties of filled composites depend strongly on the filler size, filler–matrix interface adhesion, and filler loading. Nanotechnology could help in manipulating and controlling the interfacial properties between oil palm biofiller with matrix in biocomposites. This is due to the size advantage of nanoparticles, which permitted high surface contact area with matrix. Biocomposites enhanced with oil palm biomass filler can thus be widely produced and applied by optimizing all the parameters and factors that predominantly influence the properties.