Dynamic mechanical properties and thermal properties of longitudinal basalt/woven glass fiber reinforced unsaturated polyester hybrid composites

This study investigates the mechanical, thermal, and chemical properties of basalt/woven glass fiber reinforced polymer (BGRP) hybrid polyester composites. The Fourier transform infrared spectroscopy (FTIR) was used to explore the chemical aspect, whereas the dynamic mechanical analysis (DMA) and thermomechanical analysis (TMA) were performed to determine the mechanical and thermal properties. The dynamic mechanical properties were evaluated in terms of the storage modulus, loss modulus, and damping factor. The FTIR results showed that incorporating single and hybrid fibers in the matrix did not change the chemical properties. The DMA findings revealed that the B7.5/G22.5 composite with 7.5 wt% of basalt fiber (B) and 22.5 wt% of glass fiber (G) exhibited the highest elastic and viscous properties, as it exhibited the higher storage modulus (8.04 × 109 MPa) and loss modulus (1.32 × 109 MPa) compared to the other samples. All the reinforced composites had better damping behavior than the neat matrix, but no further enhancement was obtained upon hybridization. The analysis also revealed that the B22.5/G7.5 composite with 22.5 wt% of basalt fiber and 7.5 wt% of glass fiber had the highest Tg at 70.80◦C, and increased by 15◦C compared to the neat matrix. TMA data suggested that the reinforced composites had relatively low dimensional stabilities than the neat matrix, particularly between 50 to 80◦C. Overall, the hybridization of basalt and glass fibers in unsaturated polyester formed composites with higher mechanical and thermal properties than single reinforced composites

Development of oil palm empty fruit bunch tablet as corrosion inhibitor for mild steel acid corrosion

The use of inhibitors is a prevailing corrosion control practice. However, the toxicological and environmental issues of conventional inhibitors have eloquently proliferated interest in developing safe and environmentally benign inhibitors. As considerable experimental evidence of nature-based inhibitors have been reported, their effectiveness are indisputable. Nonetheless, a breakthrough in this field is needed to go beyond the exploratory stage, seeking ways to implement the developed inhibitors in the industry. Considering the subject matter, this study aimed to develop an oil palm empty fruit bunch (OPEFB) tablet as a corrosion inhibitor for mild steel in 1 M hydrochloric acid (HCl). Two OPEFB treatments and one without treatment, that yield untreated, sodium hydroxide (NaOH) treated, and HCl treated OPEFB were used for inhibitor preparation. All inhibitors have been characterised and the results revealed that each inhibitor constitutes varying proportions of hemicellulose, cellulose, lignin, and extractives. The inhibition efficiencies of the inhibitors have been investigated using weight loss method at varying dosages from 0.1 to 0.5 g. The finding has shown that HCl treated OPEFB exhibited the highest inhibition efficiency (85.66%), followed by untreated (82.11%) and NaOH treated OPEFB (66.24%). All OPEFB inhibitors’ adsorptions on mild steed obeyed Langmuir isotherm and are categorised as mixed-type adsorption. HCl treated OPEFB was selected to be further characterised and investigated. Its chemical composition was explored and the results unveiled that the inhibitor comprises sugar, fatty acid, amino acid, carotenoid, and phytosterol compounds. The dosage and immersion time were then optimised using response surface methodology (RSM) to obtain maximum inhibition efficiency. An optimum point at 0.33 g and 120 h that yields 87.11% of efficiency was predicted and validated. Next, the inhibition kinetics was studied using electrochemical methods. The results uncovered that HCl treated OPEFB was a mixed type inhibitor that inhibits both anodic and cathodic reactions simultaneously. Afterwards, 15 HCl treated OPEFB compounds were analysed computationally. The results revealed that the sugar compounds exhibited good characteristic, while the carotenoid compound showed a superior characteristic for corrosion inhibition. All compounds were adsorbed in a flat position on the metal surface. Finally, an OPEFB tablet was formulated to extend the effective inhibition time using D-optimal mixture method. Three formulations with excellent inhibition performances were selected for tensile strength, disintegration time, and dissolution profile evaluations. The findings unveiled that T3, with OPEFB to GA to HPMC ratio of 66:0:34, portrayed the best tablet properties. The inhibition performance of T3 at extended immersion times from 120 h to 720 h was then investigated. The finding unveiled that T3 showed persistent inhibition effect up to 360 h. Overall, this study’s findings have shown that the OPEFB inhibitor tablet can inhibit mild steel acid corrosion effectively, and the tableting approach provides a promising way to implement nature-based inhibitors in the industry

Corrosion inhibition of mild steel by cassava peel powder in hydrochloric acid medium

Cassava peel powder (CPP) was utilized as a green corrosion inhibitor to reduce the mild steel (MS) corrosion rate (Rc) in acidic media. The weight-loss method was employed to investigate the Rc and inhibition efficiency (IE) of the mild steel specimen in uninhibited and inhibited 1.0 M HCl solution with CPP dosages of 0.2, 0.4, 0.6, 0.8 and 1.0 g for a set amount of immersion times ranging from 24 to 120 hours. Results show that the inhibitive performance of CPP increased as the inhibitor dosages increased from 0.2 to 1.0 g but decreased with a rise in immersion time, inferring that longer immersion time is unfavorable. CPP dosage of 1.0 g attained the highest inhibition efficiency of 86.77% after 24 hours immersion time. Optimization study via Response Surface Methodology (RSM) demonstrates that the optimum conditions are estimated at 1.0 g CPP dosage and 57 hours immersion period, with an efficiency of 87.20%. The thermodynamic analysis revealed that the inhibition process is spontaneous and obeyed Langmuir isotherm, and the mechanism of inhibition inclined towards chemisorption

An Overview of Molecular Dynamic Simulation for Corrosion Inhibition of Ferrous Metals

Molecular dynamics (MD) simulation is a powerful tool to study the molecular level working mechanism of corrosion inhibitors in mitigating corrosion. In the past decades, MD simulation has emerged as an instrument to investigate the interactions at the interface between the inhibitor molecule and the metal surface. Combined with experimental measurement, theoretical examination from MD simulation delivers useful information on the adsorption ability and orientation of the molecule on the surface. It relates the microscopic characteristics to the macroscopic properties which enables researchers to develop high performance inhibitors. Although there has been vast growth in the number of studies that use molecular dynamic evaluation, there is still lack of comprehensive review specifically for corrosion inhibition of organic inhibitors on ferrous metal in acidic solution. Much uncertainty still exists on the approaches and steps in performing MD simulation for corrosion system. This paper reviews the basic principle of MD simulation along with methods, selection of parameters, expected result such as adsorption energy, binding energy and inhibitor orientation, and recent publications in corrosion inhibition studies

An overview of molecular dynamic simulation for corrosion inhibition of ferrous metals

Molecular dynamics (MD) simulation is a powerful tool to study the molecular level working mechanism of corrosion inhibitors in mitigating corrosion. In the past decades, MD simulation has emerged as an instrument to investigate the interactions at the interface between the inhibitor molecule and the metal surface. Combined with experimental measurement, theoretical examination from MD simulation delivers useful information on the adsorption ability and orientation of the molecule on the surface. It relates the microscopic characteristics to the macroscopic properties which enables researchers to develop high performance inhibitors. Although there has been vast growth in the number of studies that use molecular dynamic evaluation, there is still lack of comprehensive review specifically for corrosion inhibition of organic inhibitors on ferrous metal in acidic solution. Much uncertainty still exists on the approaches and steps in performing MD simulation for corrosion system. This paper reviews the basic principle of MD simulation along with methods, selection of parameters, expected result such as adsorption energy, binding energy and inhibitor orientation, and recent publications in corrosion inhibition studies

Development and testing of an oil palm (Elaeis guineensis Jacq.) fruit digester process for kernel free in crude palm oil production

Current palm oil extraction techniques involve the digestion and pressing of entire oil palm fruitlets. However, the coexistence of mesocarp fibre and nut during pressing could inevitably result in oil loss due to fragmentation of the fibre and nut. The anticipated separation of palm mesocarp fibre and kernel prior to pressing is a potential solution to the problem. In order to enhance the extraction of crude palm oil, a digester machine with kernel free has been created. Each machine iteration consists of two processes. The first phase involved severing and removing the mesocarp fibre from the kernel (seed), as well as removing all mesocarp produced by the process, while the second phase involved releasing the nut. The effectiveness of the created machine was evaluated under various conditions, such as speed (700, 900, 1100, 1300, and 1500 rpm) and processing time (20, 30, and 40 s). The optimal condition, which consisted of a rotational speed of 1500 rpm and a separation time of 40 s, was evaluated further under loading weight (2.50, 3.75, and 5.00 kg). The optimal separation was attained with a separation speed of 1100 rpm, a time of 30 s, and a loading mass of 2.50 g, according to the results. Under these conditions, the machine could achieve a separation efficiency of 94.89 and a kernel disintegration rate of 4.29. The investigation's findings benefit the palm oil industry by eliminating processes like winnowing and nut separation through effective implementation of the kernel-free digester machine. © 2023 Elsevier B.V

Dynamic mechanical properties of natural fiber reinforced hybrid polymer composites: a review

The concerning waste management issue of natural fibers and the downsides of synthetic fibers have governed natural fibers' utilization as reinforcements in composites. Incorporating a single type of reinforcing fiber does not inevitably produce composites that meet exceptional quality standards, particularly in dynamic mechanical properties. Various studies have demonstrated excellent properties of natural fiber reinforced hybrid composites. Accordingly, this paper aims to review research related to natural fiber reinforced hybrid composites that emphasize the dynamic mechanical properties. A summary for each type of hybrid composites, including thermoset and thermoplastic polymers, biopolymers, nanocomposites, and bionanocomposites was provided. The variables of relevance in this overview are the loss modulus, storage modulus, damping factor, and glass transition temperature. Overall, the reviewed works revealed that lignocellulosic fibers are extensively used to reinforce composites. Nearly all hybridization of multiple reinforcing fibers had synergistic influences on the hybrid composites' dynamic mechanical properties. However, there are several cases whereby the addition of hybrid reinforcing particles leads to a detrimental effect on the composites’ quality. There is a limitless possibility for further improvements of natural fiber reinforced hybrid composites