Papers by Keyword: Cellulose Fibers

Abstract: Procion M dyes are widely used reactive dyes for cellulose-based textiles due to their bright colors, fastness properties, and covalent bonding capabilities. This study examines the chemical structure of Procion M dyes, highlighting key components: the chromophore, reactive group, solubilizing group, and linking group. The hydrolysis and alcoholysis of these dyes were investigated using Procion Red M-X5B and Procion Blue M-XG under various temperatures (25°C, 35°C, 45°C). Experimental setups included UV-Vis and IR spectroscopy to monitor dye concentration and functional group changes, respectively. Data revealed temperature-dependent reaction rates, with higher temperatures accelerating both hydrolysis and alcoholysis. Thermodynamic analysis showed that both processes are exothermic and spontaneous, with enthalpy changes of -20 kJ/mol (hydrolysis) and -25 kJ/mol (alcoholysis), and Gibbs free energy changes confirming spontaneity. FTIR and HPLC analyses provided insights into molecular structural changes and product formation. These results underscore the efficiency and temperature sensitivity of Procion M dye reactions, offering valuable information for optimizing textile dyeing processes.

Abstract: Electronic equipment is exposed to rough vibrations throughout its life cycle. Electronic components can be damaged by these vibrations and could lead to device failure. The conventional Printed Circuit Boards (PCBs) that form the foundation of numerous electronic devices are predominantly constructed from copper films that are bound to fiber epoxy laminates, such as FR4, which is composed of glass fibers, and FR1, which is composed of paper. Being biodegradable makes cellulose a more sustainable choice. Nonetheless, it is imperative to uphold performance criteria, and this work aims to contribute to this assessment. Using simulation studies, we compare the behavior of these two PCBs under vibrational stress. The finite element analysis (FEA) of the vibrations for the PCB samples was modelled using the Ansys software. The FEA simulations show that both types of PCBs have similar movements and accelerations at certain places on the board.

Abstract: Due to the high annual production of rice, rice straw has become a numerous agricultural waste product. We propose in this paper to produce oil sorbent for oil-water separation from waste rice straw fibers. Rice straw cellulose were extracted using 5 wt.% sodium hydroxide (NaOH) at 90 °C for 2 hours. After washing with water, rice straw fibers were tested with litmus paper until pH was neutral. A 20-minute boil was applied to sticky rice flour and water. A strainer was placed on the boiling sticky rice flour. Rice straw fibers were delicately spun, placed in the sieve, and dried at 60 °C for 24 hours. The identification of rice straw cellulose was accomplished through the utilization of Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). In order to evaluate the oil absorption capacity, it is necessary to introduce rice straw into a designated container. Adsorption was measured at time intervals of 10, 20, and 30 minutes. Cease the act of quantifying temporal intervals beyond the predetermined duration. Extract the specimen from its receptacle and proceed to measure its weight. To maximize the %adsorption, the oil sorbent weight, adsorption time, and contact area were considered. The maximum adsorption capacity of 175.67% was obtained by optimizing the following parameters: oil sorbent weight of 30.10 g, adsorption time of 30 min, and contact area of 6.25 cm². The oil sorbent, which uses waste rice straw fibers as raw materials, may have a good application possibility in the remediation of oil spills, industrial waste water, and waste water from households.

Abstract: This paper is aimed to investigate the total sand filler replacement by two types of cellulosic fibers (bleached wood pulp - WP and recycled fibers from waste paper - RF) in cement-based mortars. Two different types of cement mortar, one with addition of finely ground limestone and other with powdered granulated slag, were mixed with fibers. The changes in consistency of fresh fiber cement mortars and development of compressive and flexural strength of mortars in dependence on hardening time up to 90 days was studied. The development of compressive and flexural strength with increasing hardening time of cellulose fiber mortars and two binders with different properties confirmed that binder mixtures containing finely ground slag and recycled cellulose fibers achieved higher values of these strength parameters. Also adhesion testing of fiber cement mortars on two substrates (ceramic fitting and aerated concrete block) after 28 days of their application showed better adhesion of cement mortars with finely ground granulated slag on the ceramic fitting surface compared to the mortars containing finely ground limestone. However, any cracks have occurred on both substrates during the maturing of mortars with slag. Based on the above facts, it can be concluded that suitable plaster mixtures for their use in the interior appear the cement recipes with both cellulose fibers (wood pulp and fibers from recycled waste paper) and with finely ground limestone.

Abstract: We report on the effect of cellulose fibers on the formation of petroleum-based and bio-based polyurethane foams. The fabricated polyurethane foams (PUF) were done by reacting isocyanate with petroleum-based polyol and epoxidized soybean oil (ESBO)-based polyols via hand mixing. The addition of cellulose fibers extracted from pineapple (Ananas comosus) leaf was done to enhance the properties of the fabricated PUF. Experimental results revealed that surface morphology of the fabricated polyurethane foams with addition of cellulose fibers remain the well-defined cell structures as shown in the scanning electron micrographs although few cell ruptures were observed. Likewise, the presence of the vibrational modes of the NCO and OH were confirmed in the Fourier transform infrared (FTIR) spectra suggesting that successful formation of polyurethane foams takes place. The thermogravimetric results revealed that much higher thermal stability for the 100% ESBO-based PUF with cellulose fibers due to the presence of cellulose and triglycerides in the ESBO-based polyols which both degrades at higher temperature. This suggest that 100% ESBO-based PUF with cellulose fiber exhibit higher thermal stability provides promising application for thermal insulations.

Abstract: Concrete is considered as a non-combustible building material. However, at High-Performance Concrete (HPC) is due to its dense structure more likely to occur in explosive spalling. This results in lost of load bearing capacity function of concrete. This paper deals with design, production and testing of the cement-based concrete with the use of different fibers (polypropylene fibers and cellulose fibers). It also assesses the influence of high temperature on strength, visual changes of specimens, changes of surface and degradation of testing specimens due to heat loads according to normative heat curve and also according to hydrocarbon curve.

Abstract: Biocomposites sheets were prepared by compression molding from mixtures of corn starch plasticized by glycerol as matrix and cellulose fibers, extracted from used office paper, as reinforcement filler with contents ranging from 0 to 8% wt/wt of fibers to matrix. Properties of composites were determined by mechanical tensile test, differential scanning calorimetry, thermogravimetric analysis, water absorption measurement, and scanning electron microscopy. The results showed that higher fibers content raised the tensile strength and elastic modulus up to 109% and 112%, respectively, when compared to the non-reinforced thermoplastic starch (TPS). The addition of the fibers improved the thermal resistance and decreased the water absorption up to 63.6%. Scanning electron microscopy illustrated a good adhesion between matrix and fibers.

Abstract: MDP (medium density particleboard) panels are normally graded in composition along their cross-section, using low-size particles and high concentration of adhesive on the particleboard surface (leading to improved physical and mechanical properties), and high-size particles in the particleboard core (interior), which provide higher porosity. Then, the aim of this study was to evaluate the impact of using different contents of bamboo particles in the particleboard core, on their physical and mechanical properties. The production of the panels was carried out using Pinus oocarpa (P) and Bambusa vulgaris var. Vittata (B) particles in different contents (100% P, 100% B, 50% de B e 50% de P, 25% de B e 75% de P, 75% de B e 25% de P) in the core of the particleboards. The face of the particleboards were composed of P particles. The panels were produced with nominal density of 0.70 g/cm³, 40:60 face:core relation, 11% urea-formaldehyde adhesive in the faces and 8% adhesive for the core, specific pressure of 3.92 MPa, 160 °C temperature and pressing time of 8 min. After seasoning, the panels were submitted to evaluation of the thickness swelling (TS) and water absorption (WA) after 2 and 24 h of immersion, apparent density (AD), internal bonding (IB), modulus of rupture (MOR) and modulus of elasticity (MOE) under static bending. There was no statistical difference between the treatments for AD, IB, MOR and MOE values. Panels produced with high contents of bamboo particles (100% B, 75% B e 50% B) in the core, presented the lower WA and TS values, leading to improved dimensional stability than panels with only pinus particles. The present results show the important impact of using functionally gradation and bamboo particles on the physical properties of the MDP panels produced.

Abstract: Cyclodextrins (CDs) can form inclusion complexes with a variety of molecules making them very attractive in different areas, such as pharmaceutics, biochemistry, food chemistry and papermaking. In this communication the preparation of β-cyclodextrin-grafted cellulose fibers was carried out by reacting β-cyclodextrin with cellulose fiber via citric acid (CA). Both fourier transform infrared (FTIR) and cross polarization magic angle spinning solid state nuclear magnetic resonance (CP-MAS NMR) indicated that β-CDs had been chemically attached to cellulose backbone through the formation of ester bonds. Furthermore, the β-CD-grafted cellulose fibers formed inclusion complexes with ciprofloxacin hydrochloride (CipHCl). And the β-CD-grafted cellulose fibers loaded with CipHCl showed excellent antibacterial activity against E.coli and S.aureus.

Abstract: A lot of achievements of contemporary science are connected with green composites producing and properties investigation. Variations of matrices, reinforcement and their combinations are innumerable. This study is focused on polylactic acid based biocomposites exploitation properties (flexural strength and modulus, impact strength, microhardness and water uptake) investigation results. Different origin cellulose containing fibers (hemp, cotton, tetra package cellulose, and hard wood) without and with modification were used as reinforcement.