13 research outputs found
Development Of New Organic Wood Paints With Lignin As Additive
Lignin has been used as additive in preparation of the new organic paints. Soda lignin was extracted from black liquor of soda-AQ (anthraquinone) pulping of oil palm empty fruit bunch (EFB) fibers by 20% sulfuric acid precipitation. Two different types of azo pigment namely, phenyl-azo-2-naphthol and 4-Hydroxyphenylazo-3-N-(4-hydroxyphenyl)maleimide were synthesized by azo coupling reaction. Phenyl-azo-2-naphthol which was represented as aromatic azo pigment was produced from the reaction of diazonium salt (phenyldiazonium chloride) with pure 2-naphthol as the coupling agent whereas a new heterocyclic coupling agent namely, N-(4-hydroxy-phenyl)maleimide was synthesized by the reaction of maleic anhydride and p-aminophenol in the presence of di-phosphorus pentoxide (P2O5) as a catalyst
Alkaline Sulfite Anthraquinone and Methanol (ASAM) Pulping Process of Tropical Bamboo (Gigantochloa scortechinii)
This chapter explores the characteristic potentials of alkaline sulfite anthraquinone and methanol (ASAM) pulping of bamboo culms (Gigantochloa scortechinii) in the industrial production of pulp and paper for packaging. The biometric characterization results of the bamboo culms show that bamboo has fiber length of 1980–4000 μm, Runkel ratio of 0.86, and flexibility ratio of 50.19, while the chemical compositions of the bamboo contain 47.67% cellulose, 68.33% holocellulose, 26% lignin, and 3.69% solvent extractive, which give good paper quality fiber and also falls within the range of wood from softwoods species. The study revealed that the optimum ASAM pulping parameters was at 16% NaOH and 90 min cooking time, resulting in Kappa number of 14.17 and pulp yield of 49.06%, while the paper tensile index of 20.86 Nm/g, tear index of 22.64 mN.m2/g, and brightness of 39.32% were obtained. The biometric and chemical characterizations of the ASAM pulped bamboo have shown that ASAM pulped bamboo produces high-quality pulp and paper suitable for packaging and printing paper. Hence, the use of bamboo materials can reduce the burden on the forest, due to the increasing demand for paper and paper products, while supporting the natural biodiversity
Recent Advancement in Physico-Mechanical and Thermal Studies of Bamboo and Its Fibers
Bamboo has its own role in the development of society. It is widely used as a support tools for sustainable farming and being exceptional resource for variety of income and employment-generating systems. This overlooked biomass provides food, raw material, shelter, medicine for large part of world’s population. Bamboo has given a great support to mankind by providing building materials that are extensively used for household products. It has found a good place for industrial applications due to advances in processing technology and increased market demand. Numerous fundamental studies were carried out to highlight their fundamental characteristics prior to industrial exploitation or high end bamboo-based biomaterials. The mechanical and physical properties of bamboo have noteworthy effects on their durability and strength. Thermogravimetry is one of the key sensitive technique that characterizes the mechanical responses of materials by monitoring property changes with respect to the temperature. Comprehensive review and study on thermal analysis are useful for quantitative determination of the degradation behaviour and the composition of the material. The magnitude and location of the derivative thermogravimetric curve also provides information of the interaction between the material components at various temperature scales. Therefore, these studies can be focused to evaluate the basic fundamental problems faced and thus, a well-designed research and development towards sustainability can be achieved
Development and characterization of bamboo fiber reinforced biopolymer films
A paradigm shift from petrochemical based packaging films for food packaging due to its non-renewable and waste disposal challenges has motivated research interest in development and characterization of biopolymer films. In this study, biocomposite films was prepared using bamboo fiber to reinforce modified and unmodified red seaweed SW Kappaphycus alvarezii, resulting in improved mechanical characteristics of 109.1 MPa tensile strength, 55.4 MPa Young's Modulus and 22.3% stretchability prior to breakage at the optimum value of 15% bamboo fibers loadings for unmodified biocomposite. There was general improvement in the fiber/matrix interface of the modified SW based composite films over the biopolymer films from unmodified SW bamboo reinforced films resulting in improved water vapour barrier as the fiber load increases up to Water vapour permeability value of 5.2 (g/s/m2/Pa)., while the contact angle as high as 91° was obtained. FTIR analysis validates the effective interaction of both the bamboo fibers and the seaweed matrix without any significant biochemical alteration of the seaweed within the frameworks of composite films. SEM characterization and contact angle measurement indicate that heterogeneous surface modification of the biopolymer film increases with the fiber loading. Results demonstrated the potential use of the renewable and biodegradable biopolymer composite films as packaging films useful in the food industry
Microbial-induced CaCO3 filled seaweed-based film for green plasticulture application
This work aimed to develop green biodegradable film using red seaweed (Kappaphycus alvarezii) as a base matrix and calcium carbonate (CaCO3) as a filler to enhance the properties of the red seaweed material for plasticulture purpose. CaCO3 which was produced by microbially induced precipitation (MB-CaCO3) using Bacillus sphaericus, was characterized and compared with the commercial CaCO3 (CCaCO3). FESEM image revealed that the size of MB-CaCO3 was smaller and more uniform compared to CCaCO3. FTIR and XRD analyses confirmed the existence of crystalline polymorph of calcite in MB-CaCO3, which contained a higher percentage of calcite than CCaCO3. However, the crystallinity and thermal stability of MB-CaCO3 was lower than CCaCO3. From the results of physical, mechanical and thermal properties of composite films filled with CCaCO3 and MB-CaCO3 fillers, the optimum loading of CCaCO3 and MB-CaCO3 was found at 0.1% and 0.15%, respectively. Composite films filled with MB-CaCO3 promote brighter film, better water barrier, hydrophobicity and biodegradability compared to CCaCO3. Since the effect of MB-CaCO3 on film functional properties was comparable to CCaCO3, it can be used as an alternative to CCaCO3 as inorganic filler for composite films in agriculture applications
Synthesis of New Azo Compounds Based on N-(4-Hydroxypheneyl)maleimide and N-(4-Methylpheneyl)maleimide
Maleic anhydride was reacted with p-aminophenol and p-toluidine in the presence of di-phosphorus pentoxide (P2O5) as a catalyst to produce two compounds: N-(4-hydroxy-phenyl)maleimide (I) and N-(4-methylphenyl)maleimide (II). The new azo compounds I(a-c) and II(a-c) were prepared by the reaction of I and II with three different aromatic amines, namely aniline, p-aminophenol and p-toluidine. The structures of these compounds were confirmed by CHN, FT-IR, 1H-NMR, 13C-NMR, mass spectrum and UV/Vis spectroscopy
Synthesis of New Azo Compounds Based on N-(4-Hydroxypheneyl)maleimide and N-(4-Methylpheneyl)maleimide
Butler matrix based beamforming networks for phased array antenna systems: A comprehensive review and future directions for 5G applications
Due to the rapid development of wireless communication technologies, the number of wireless users are radically increasing. Currently, ~23 billion wireless devices are connected to the internet, and these numbers are expected to increase manifolds in the years to come. The technology growth of the fifth-generation (5G) wireless systems will be needed to meet this high demand of the network. 5G wireless systems offer data-rates of up to 10Gbps, 1-ms latency, and reduced power consumption. It is a known fact that 5G wireless systems will be exploiting beyond the presently used 3 GHz microwave and millimetre-wave (mm-wave) frequency bands. This is the primary driver in the development of the 5G wireless system. Multi-beam Phased array antenna (PAA) systems are typically used in the deployment of 5G systems for high-gain and directionality. In current 5G and future Beyond 5G (B5G) antenna array systems, beamforming networks (BFNs) such as the Butler Matrix (BM) will play a key role in achieving multi-beam characteristics. So, this paper presents an extensive review of the BM based BFNs, and discusses which type of BM will be suitable for the phased array antenna (PAA) systems in the upcoming 5G and next-generation of B5G wireless systems. Moreover, this paper also summarizes the different types of BM designs based on the number of layers. The BMs are classified into the bi-layer, tri-layer, and four-layer structures. It includes different techniques that have been used to solve the problem of crossing, narrow bandwidth, and size reduction of the BM. From the previous studies, it is found that most of the past research work was performed using the bilayer BM system, whereas the difficult geometries like tri- and four-layer BM are avoided due to their complex fabrication process. It is also found in this paper that the metamaterial (MTM) based bi-layer BM achieves low insertion-loss and phase-error, excellent bandwidth and compact size, and good S-parameter performance, which makes them an ideal BFN candidate for the upcoming 5G and next-generation B5G systems
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
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%