China
Africa
Explore chapters and articles related to this topic
Reinforced composite materials
Published in Andrew Livesey, Motorcycle Engineering, 2021
The first manmade plastics were produced in this country in 1862 by Alexander Parkes and were the forerunner of celluloid. Since then, a large variety of plastics has been developed commercially, particularly in the last 25 years. They extend over a wide range of properties. Phenol formaldehyde is a hard thermoset material; polystyrene is a hard, brittle, thermoplastic; polythene and plasticized polyvinyl chloride (PVC) are soft, tough thermoplastic materials; and so on. Plastics also exist in various physical forms. They can be bulk solid materials, rigid or flexible foams, or in the form of sheet or film. All plastics have one important common property. They are composed of macromolecules, which are large chain-like molecules consisting of many simple repeating units. The chemist calls these molecular chains polymers. Not all polymers are used for making plastic moldings. Manmade polymers are called synthetic resins until they have been molded in some way, when they are called plastics.
® IRA-900 ion exchange resin for the sorption of selenate and sulfate: Equilibrium, kinetic and regeneration studies
Published in Lea Chua Tan, Anaerobic treatment of mine wastewater for the removal of selenate and its co-contaminants, 2018
L.C. Tan, E.M. Calix, E.R. Rene, Y.V. Nancharaiah, E.D. van Hullebusch, P.N.L. Lens
IX processes reversibly exchange the adsorbate (ion contaminant of interest) for a similarly charged ion that is attached to an immobilized resin on a solid surface material resin, e.g. synthetic or natural zeolites. Different kinds of both natural adsorbents and synthetic resins are available for removing Se oxyanions (Santos et al. 2015). The use of commercially available organic synthetic resins is a well-understood technology, where strong basic anion (SBA), weak basic anion (WBA) or chelating resins are employed for Se removal from polluted water. Synthetic resins can be anionic or cationic resins and can be regenerated by simple backwashing with an acid or alkaline solution (Erosa et al. 2009). SBA type materials were identified as the best candidate for anion removal due to their fixed positively-charged groups, can act as anion exchangers in wider pH ranges, and can withstand to at least 100°C (Mac Namara et al. 2015). SBA functionalization is generally based on fixed quaternary amines, i.e. ammonium cations, which promote an electrical attraction between the adsorbate and adsorbent surface following an IX mechanism (Clifford and Weber Jr. 1983).
Monomers, Polymers, and Plastics
Published in James G. Speight, Handbook of Petrochemical Processes, 2019
Binders may be natural materials, e.g., cellulose derivatives, casein, or milk protein, but are more commonly synthetic resins. In either case, the binder materials consist of polymers. Cellulose derivatives are made from cellulose, a naturally occurring polymer; casein is also a naturally occurring polymer. Synthetic resins are polymerized, or built up, from small simple molecules called monomers. Plasticizers are added to a binder to increase flexibility and toughness. Fillers are added to improve particular properties, e.g., hardness or resistance to shock. Pigments are used to impart various colors.
Thermal buckling of flax fibre reinforced epoxy laminated composite plate using finite element analysis
Published in International Journal for Computational Methods in Engineering Science and Mechanics, 2022
Guru Anandan, Venkatachalam Gopalan, Senthilnathan Natarajan
The development and use of the reinforced polymer matrix composites with natural fibre (flax fibres) has increased manifold during this decade due to the extensive research that are carried out in the academic and industrial establishments. The unique characteristics of the natural fibres such as less weight, availability in large quantity, renewable nature, and bio-degradable property have turned the focus of the industries on natural fibre reinforced composites. Evolution in research on plant-based composites extends its application in various automotive/aerospace industries. Equal attention has to be given for composites reinforced with natural fibres [1–4]. The natural fibres are available in many parts of the universe in the form of a bundle or as a single fibre. Their exist difference in the properties of the natural fibres based on the availability. One disadvantage is the toughness of these composites is less [5]. The main parameters that have to be focussed on while preparing the composites are the moisture absorption capacity of the fibre, bonding between the fibres and the matrix, and the wettability property. These pitfalls can be addressed through alkali treatments [6]. Natural or synthetic resins can be used as a matrix component in natural fibre reinforced composites preparation. These natural composites have mechanical properties that can be used as a replacement for synthetic or metals in construction purpose, automotive seating, and furniture [7].
Study of epoxy shielding material with barium sulphate for development of radiation protection materials in low-dose diagnostic X-ray
Published in Radiation Effects and Defects in Solids, 2021
Nuttapong Danthanavat, Manus Mongkolsuk, Gunjanaporn Tochaikul, Soontaree Sriwongta, Atitaya Piyajaroenporn, Cholakorn Lithreungnam, Nutthapong Moonkum
To date, there has been little information on the radiation stability of barium sulphate mixed with other materials such as polyester resins. Polyester resins are synthetic resins formed by the reaction of dibasic organic acids and polyhydric alcohols. Maleic Anhydride is a commonly used raw material with diacid functionality in unsaturated polyester resins. Unsaturated polyester resins are used in sheet moulding compounds, bulk moulding compounds and the toners of laser printers. Epoxy-ester coatings are thermosetting resins produced from the reaction between the epoxy group of epoxy resin and carboxylic group of fatty acids at elevated temperatures (12). Epoxy-esters have a variety of applications in solvent and water-based systems as coating materials, adhesives, laminated boards, printing inks, molding resins and electro-insulating varnishes (13). Moreover, the previous study investigated the anticorrosion and mechanical behavior of epoxy-alkyd/polyaniline emeraldine salt coating composite, smart corrosion protection was observed for this composite (14).
Optimization of dry compressive strength of groundnut shell ash particles (GSAp) and ant hill bonded foundry sand using ann and genetic algorithm
Published in Cogent Engineering, 2019
Chidozie Chukwuemeka Nwobi-Okoye, Patrick Chukwuka Okonji, Stanley Okiy
Usually, various additives are added to sand to make it suitable for use as foundry sand. Some of these additives such as synthetic resins, like Furan resin and phenol-formaldehyde resins are hazardous and are not environmentally friendly. Moreover, these binder systems are too sophisticated and expensive for foundries in developing countries that have abundant natural raw materials but without needed advanced technologies for proper use of the resources. In this regard, Okonji, Nwobi-Okoye, and Atanmo (2018) developed a cheap and eco-friendly binding material using groundnut shell ash (GSAp) and ant hill soil for green and dry sand casting application in Nigerian foundries. Dry sand casting involves baking the mould in an oven at a certain temperature for a given time period in order to strengthen the mould before casting. Dry sand casting is much more expensive than green sand casting and it is usually used for casting intricate shapes and complex parts used in machines and equipment. Obtaining the high compressive strength required for dry sand casting comes at a cost because as the strength increases the cost of the mould increases. This is a typical case of conflicting objectives because the engineer often desires high strength at a minimum cost. Hence, in order to optimize the mould required for dry sand casting, a multi-objective optimization is required.