Long-Term Durability of Polymeric Matrix Compositespresents a comprehensive knowledge-set of matrix, fiber and interphase behavior under long-term aging conditions, theoretical modeling and ...experimental methods. This book covers long-term constituent behavior, predictive methodologies, experimental validation and design practice. Readers will also find a discussion of various applications, including aging air craft structures, aging civil infrastructure, in addition to engines and high temperature applications.
Sansevieria trifasciata fibre (STF) is a lignocellulosic material which could be utilised for reinforcement composites. Surface modification is often needed to improve the compatibility of ...hydrophilic STF and hydrophobic resin. In this study, treatments for natural fibres to attain superhydrophobic properties were carried out using silica nanoparticles and fluorosilane. Sansevieria trifasciata fibres (STF) were subjected to treatment by deposition of silica (SiOsub.2) nanoparticles which were prepared by the sol-gel method, then followed by modification with fluorosilane, namely 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane (PFOTS). The presence of SiOsub.2 nanoparticles and PFOTS were evaluated using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX). The crystallisation properties and thermal behaviour of STF were studied through X-ray diffraction (XRD) and thermogravimetric (TGA) analysis, respectively. The hydrophobicity of STF was determined by water contact angle (WCA) measurement. The results show that nanoscale SiOsub.2 particles were deposited on the STF surface, and PFOTS were covalently linked to them. The SiOsub.2 nanoparticles provide surface roughness to the fibres, whereas the long-chain fluorine on PFOTS lowered the surface free energy, and their combination in these treatments has successfully modified the STF surface from hydrophilic into superhydrophobic with a WCA of 150° and sliding angle of less than 10°. Altogether, a non-toxic, simple, and promising method of imparting hydrophobicity on natural fibres was developed, opening new opportunities for these fibres as reinforcement for composite parts.
Syzgium cumini (L.) Skeels powder (S. cumini powder), also known as Jamun, is well-known for its various medical and health benefits. It is especially recognized for its antidiabetic and antioxidant ...properties. Thus, S. cumini powder is used in various industries, such as the food and cosmetic industries. In this work, the fruit of S. cumini was utilized; its seeds were extracted, dried, and ground into powder. The ground powders were subjected to various techniques such as physicochemical tests, Fourier transform infrared (FTIR) spectroscopy, X-ray diffractometry (XRD), particle size analysis, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and antioxidant analysis. From the physicochemical tests, it was revealed that the jamun seed filler contained cellulose (43.28%), hemicellulose (19.88%), lignin (23.28%), pectin (12.58%), and wax (0.98%). The FTIR analysis supported these results. For instance, a peak at 2889 cmsup.−1 was observed and associated with CH stretching, typically found in methyl and methylene groups, characteristic of cellulose and hemicellulose structures. The XRD results demonstrated that the crystallinity index of the jamun seed filler was 42.63%. The particle analysis indicated that the mean (average) particle size was 25.34 μm. This observation was ensured with SEM results. The EDX spectrum results showed the elemental composition of the fillers. Regarding thermal degradation, the jamun seed filler had the ability to withstand temperatures of up to 316.5 °C. Furthermore, endothermic and exothermic peaks were observed at 305 °C and 400 °C, respectively. Furthermore, the antioxidant property of the powder displayed a peak scavenging activity of 91.4%. This comprehensive study not only underscores the viability of S. cumini powder as a sustainable and effective particulate filler in polymer composites but also demonstrates its potential to enhance the mechanical properties of composites, thereby offering significant implications for the development of eco-friendly materials in various industrial applications.
In today's world, bioplastics are becoming increasingly prominent owing mainly to scarcity of oil, increase in the cost of petroleum-based commodities, and growing environmental concerns with the ...dumping of non-biodegradable plastics in landfills. This book summarizes the field of bioplastics by illustrating how they form a unique class of research area that integrates pure and applied sciences such as chemistry, engineering and materials science, to initate solutions. Compelling science demystics this complex and often ambiguous branch of study for benefit of all those concerned with bioplastics.
Jackfruit mucilage (JM) obtained from the fruit, Artocarpus heterophyllus was melt blended with poly(epsilon-caprolactone) (PCL). The physical properties of the blends with more than 60 wt% PCL were ...investigated. Depression in the equilibrium melting temperature (T.sup.o.sub.m) and the presence of extinction rings in the spherulites of PCL in the blends confirmed miscibility of the two components. The carbonyl and the C--O--C groups of PCL and JM were responsible for the interactions as identified by Fourier transform infrared spectroscopy. The thermal stability of PCL decreased marginally in the blends with increasing JM content. The scanning electron microscopy (SEM) images indicated that no phase separation occurred. Porosity and the mechanical strength of the blends decreased with increasing JM content. Blends exposed to porcine pancreatic lipase showed enzymatic degradation of JM but not PCL and SEM images showed holes in the sample indicative of selective degradation of JM. Cell growth inhibition technique using the L929 fibroblasts cells showed the degree of inhibition was dependent on the increasing JM content in the blends. Blends with low JM content have the potential to be used for increased cell viability while blends with high JM content can be used for the treatment of cancer.
Fiber reinforced polymer composites are an extremely broad and versatile class of material.Their high strength coupled with lightweight leads to their use wherever structural efficiency is at a ...premium. Applications can be found in aircraft, process plants, sporting goods and military equipment. However they are heterogeneous in construction and antisotropic, which makes making strength prediction extremely difficult especially compared to that of a metal. This book brings together the results of a 12year worldwide failure exercise encompassing 19 theories in a single volume. Each contributor describes their own theory and employs it to solve 14 challenging problems. The accuracy of predictions and the performance of the theories are assessed and recommendations made on the uses of the theories in engineering design.All the necessary information is provided for the methodology to be readily employed for validating and benchmarking new theories as they emerge.Brings together 19 failure theories, with many application examples. Compares the leading failure theories with one another and with experimental data Failure to apply these theories could result in potentially unsafe designs or over design.
Numerical simulation of poly Zambaldi, Edimilson; Magalhaes, Ricardo R; Dias, Matheus C ...
Polymer engineering and science,
12/2022, Letnik:
62, Številka:
12
Journal Article
Recenzirano
The advancement of biodegradable polymer application is increasingly growing through various combinations with other materials. There is a great expectation on how the use of those new materials can ...be expanded not only as a replacement for polymers of fossil origin but also in the replacement of metallic materials. Thus, this work presents the use of numerical simulations as a tool to evaluate and reengineer the application of a biodegradable composite constituted by nanofibrillated cellulose (NFC) and poly(lactic acid) (PLA), in the construction of mechanical components. The academic and industrial interest of this work led to a case study using the finite element analysis (FEA) and the composites produced, where it was evaluated the technical feasibility of replacing a mechanical component constructed with 1060 H12 aluminum alloy.
