Rudi Dungani

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.

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.

Effect of jute fibre loading on the mechanical and thermal properties of oil palm-epoxy composites

Bilayer hybrid composites fabricated by hand lay-up technique by impregnating oil palm empty fruit bunch and jute fibre mats with epoxy resin and cured at 100℃ for 1 h followed by post curing at 105℃. Bilayer hybrid composites were prepared by varying the relative weight fraction of the two fibres. The mechanical, morphological and thermal properties of oil palm/jute bilayer hybrid composites were carried out. When the jute fibre loading is increased in the bilayer hybrid composites, flexural strength and modulus of the hybrid composites will be higher. The hybridization of the jute fibres with oil palm composite decreased the impact strength of the bilayer hybrid composites. Analysis of variance statistical of flexural and impact properties were also carried out; there is a statistically significant difference between the mean flexural strength, flexural modulus and impact strength from one level of composite to another at the 95.0% confidence level. Thermogravimetric analysis showed that thermal stability of oil palm composites increased with development of bilayer hybrid composites. Scanning electron micrographs of impact fracture samples are taken to study the failure mechanism, and fibre/matrix interface adhesion.

Microstructural Study, Tensile Properties, and Scanning Electron Microscopy Fractography Failure Analysis of Various Agricultural Residue Fibers

This paper presents an approach to examine the microstructural properties and mechanical behavior of coconut husks, banana pseudo-stem, pineapple leaf, and sugarcane bagasse fibers by scanning electron microscope and mini-tensile tester, respectively. Single fiber bundles were examined by using scanning electron microscope. Tensile tests were performed at different diameters (0.15–0.55 mm) and gauge lengths (10, 15, 20, and 30 mm/min) to assess the effects of diameter and gauge length on tensile properties. It was found that fibers consisted of different types of regularly arranged cells. The tensile strength (310 MPa) and Young’s modulus (7.4 GPa) of pineapple leaf fiber bundles showed the highest value compared to the other fibers. The tensile strength and Young’s modulus decreased with the increase of diameter and gauge length of fiber bundles. Scanning electron microscopic fractography analysis showed comparatively heterogeneous ruptures associated with more participants of microfibrils for pineapple leaf and banana pseudo-stem fibers compared to coconut husk and sugarcane bagasse fibers. These fractographic observations were discussed in the light of current knowledge of the microstructure of each fiber and the corresponding mechanical properties.

Properties enhancement using oil palm shell nanoparticles of fibers reinforced polyester hybrid composites

Oil palm shell (OPS) nanoparticles were utilized as filler in fibers reinforced polyester hybrid composites. The OPS nanoparticles were successfully produced from the raw OPS using high-energy ball milling process. Fundamental properties including morphology, crystalline size, and particle size of the OPS nanoparticles were determined. Tri-layer natural fiber reinforcement (kenaf–coconut–kenaf fiber mat) polyester hybrid composites were prepared by hand lay-up techniques. The influences of the OPS nanoparticles loading in the natural fibers reinforced polyester hybrid composites were determined by analyzing physical, mechanical, morphological, and thermal properties of the composites. Results showed that the incorporation of the OPS nanoparticles into the hybrid composites enhanced the composite properties. Further, the natural fibers reinforced polyester hybrid composite had the highest physical, mechanical, morphological, and thermal characteristics at 3 wt.% OPS nanoparticles loading.

16 – The use of bamboo fibres as reinforcements in composites

Abstract: Bamboos are of notable economic and cultural significance all over the world, especially in South Asia, Southeast Asia and East Asia, being used for building materials, as a source of food, as a decorative product and as a versatile raw product. Bamboo also has significant potential in composite making due to its high strength, environmentally friendly nature, rapid growing properties, low cost, availability and sustainability. This chapter summarizes production processes for bamboo fibres and their applications in composites. The production of nanocellulose from bamboo fibres is also briefly discussed. Overall, the chapter aims to show the versatility of bamboo fibre in various applications from construction to culinary.

Isolation and Characterization of Cellulose Nanofibers from Gigantochloa scortechinii as a Reinforcement Material

Cellulose nanofibers CNF were isolated from Gigantochloa scortechinii bamboo fibers using sulphuric acid hydrolysis. This method was compared with pulping and bleaching process for bamboo fiber. Scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and thermogravimetric analysis were used to determine the properties of CNF. Structural analysis by FT-IR showed that lignin and hemicelluloses were effectively removed from pulp, bleached fibers, and CNF. It was found that CNF exhibited uniform and smooth morphological structures, with fiber diameter ranges from 5 to 10 nm. The percentage of crystallinity was significantly increased from raw fibers to cellulose nanofibers, microfibrillated, along with significant improvement in thermal stability. Further, obtained CNF were used as reinforcement material in epoxy based nanocomposites where tensile strength, flexural strength, and modulus of nanocomposites improved with the addition of CNF loading concentration ranges from 0 to 0.7%.

Non-wood Renewable Materials: Properties Improvement and Its Application

Plant biomass are woody and non-wood materials (e.g., oil palm, bamboo, rattan, bagasse, and kenaf) and are abundant and renewable resource. Unfortunately, the heavy reliance on this resource is a threat to forest ecosystems and a recipe for accelerated land resource degradation. Due to the increasing scarcity of wood resources, many rural communities have shifted to utilization of crop residues for many different applications. The non-wood biomass is readily available, environmental friendly, and technologically suitable, and therefore, an excellent raw material for the future. The non-wood materials like bamboo, rattan, oil palm, and bagasse have superior properties and durability, which can be further prolonged by the modification treatment. The modification treatments increase the performance of the non-wood and could make it suitable for applications in many fields ranging from construction industry to automotive industry. This chapter deals with the properties improvement techniques of the selected non-wood biomasses and evaluates its applications for various purposes. The new developments dealing with the improvement of non-wood properties have also been presented in the chapter. The performance of non-wood biomass materials has been compared to the wood-based materials. Recent studies pertaining to the above topics have also been cited. Finally, the advanced applications of the improved non-wood biomasses have been highlighted.

Irradiation Pretreatment of Tropical Biomass and Biofiber for Biofuel Production

Interest on biofuel production from biomass and biofiber has gain great attention globally because these materials are abundant, inexpensive, renewable, and sustainable. Generally, the conversion of biomass and biofiber to biofuel involves several processes including biomass production, pretreatment, hydrolysis, and fermentation. Selecting the most efficient pretreatment is crucial to ensure the success of biofuel production since pretreatment has been reported to contribute substantial portion on the production cost. The main goal of the pretreatment is to enhance digestibility of the biomass and biofiber, and to increase sugar production prior to fermentation process. To date, several pretreatment methods have been introduced to pretreat biomass and biofiber including irradiation. This book chapter reviews and discusses different leading irradiation pretreatment technologies along with their mechanism involved during pretreatment of various tropical biomass and biofiber. This chapter also reviews the effect of irradiation pretreatment on the biomass and biofiber component, which could assist the enzymatic saccharification process.

Preparation and Characterization of Microcrystalline Cellulose from Sacred Bali Bamboo as Reinforcing Filler in Seaweed-based Composite Film

Microcrystalline cellulose (MCC) isolated from cheap, fast-growing and abundant accessible Sacred Bali bamboo (Schizostachyum brachycladum) was utilized as reinforcement material in the seaweed-based composite film. Isolation of MCC was carried out by using a combination of pulping, bleaching and acid hydrolysis process. This study emphasized on the feasibility of MCC production from Sacred Bali bamboo by studying its properties using X-ray diffraction (XRD), scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The commercial-MCC (CMCC) was used as reference material. Results showed that the production yield, moisture content (MC) and fiber length of bamboo-MCC (BMCC) were 83.37±1.48 %, 4.50±0.5 %, and 0.47±0.02 mm, respectively. According to the chemical analysis by FTIR, both lignin and hemicellulose were completely removed from BMCC, and thus, improved the crystallinity (78 %) and thermal stability (≈325 °C) of BMCC. This study also revealed that MCC produced from Sacred Bali bamboo demonstrated strong mechanical reinforcement effect in the seaweed-based film. Hence, Sacred Bali bamboo-MCC could be used as reinforcement material in the polymer.