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Environmental Stress Cracking
Environmental Stress Cracking (ESC) is one of the most common causes of unexpected brittle failure of thermoplastic (especially amorphous) polymers known at present. According to ASTM D883, stress cracking is defined as "an external or internal crack in a plastic caused by tensile stresses less than its short-term mechanical strength". This type of cracking typically involves brittle cracking, with little or no ductile drawing of the material from its adjacent failure surfaces. Environmental stress cracking may account for around 15-30% of all plastic component failures in service.H. F. Mark (2004). Encyclopedia of Polymers Science and Technology – 3rd Ed. Vol 12. John Miley & Sons Inc. This behavior is especially prevalent in glassy, amorphous thermoplastics. Amorphous polymers exhibit ESC because of their loose structure which makes it easier for the fluid to permeate into the polymer. Amorphous polymers are more prone to ESC at temperature higher than their glass tra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temperature
Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measurement, measured with a thermometer. Thermometers are calibrated in various Conversion of units of temperature, temperature scales that historically have relied on various reference points and thermometric substances for definition. The most common scales are the Celsius scale with the unit symbol °C (formerly called ''centigrade''), the Fahrenheit scale (°F), and the Kelvin scale (K), the latter being used predominantly for scientific purposes. The kelvin is one of the seven base units in the International System of Units (SI). Absolute zero, i.e., zero kelvin or −273.15 °C, is the lowest point in the thermodynamic temperature scale. Experimentally, it can be approached very closely but not actually reached, as recognized in the third law of thermodynamics. It would be impossible to extract energy as heat from a body at that temperature. Tem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LDPE
Low-density polyethylene (LDPE) is a thermoplastic made from the monomer ethylene. It was the first grade of polyethylene, produced in 1933 by Imperial Chemical Industries (ICI) using a high pressure process via free radical polymerization. Its manufacture employs the same method today. The EPA estimates 5.7% of LDPE ( resin identification code 4) is recycled in the United States. Despite competition from more modern polymers, LDPE continues to be an important plastic grade. In 2013 the worldwide LDPE market reached a volume of about US$33 billion. Despite its designation with the recycling symbol, it cannot be as commonly recycled as No. 1 (polyethylene terephthalate) or 2 plastics (high-density polyethylene). Properties LDPE is defined by a density range of 917–930 kg/m3. At room temperature it is not reactive, except to strong oxidizers; some solvents cause it to swell. It can withstand temperatures of continuously and for a short time. Made in translucent and opaque v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasticiser
A plasticizer ( UK: plasticiser) is a substance that is added to a material to make it softer and more flexible, to increase its plasticity, to decrease its viscosity, and/or to decrease friction during its handling in manufacture. Plasticizers are commonly added to polymers such as plastics and rubber, either to facilitate the handling of the raw material during fabrication, or to meet the demands of the end product's application. For example, plasticizers are commonly added to polyvinyl chloride (PVC), which otherwise is hard and brittle, to make it soft and pliable; which makes it suitable for products such as shower curtains, vinyl flooring, clothing, bags, flexible plastic tubing, and electric wire insulation/coating. Plasticizers are also often added to concrete formulations to make them more workable and fluid for pouring, thus allowing the water contents to be reduced. Similarly, they are often added to clays, stucco, solid rocket fuel, and other pastes prior to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Automotive Industry
The automotive industry comprises a wide range of companies and organizations involved in the design, development, manufacturing, marketing, and selling of motor vehicles. It is one of the world's largest industries by revenue (from 16 % such as in France up to 40 % to countries like Slovakia). It is also the industry with the highest spending on research & development per firm. The word ''automotive'' comes from the Greek ''autos'' (self), and Latin ''motivus'' (of motion), referring to any form of self-powered vehicle. This term, as proposed by Elmer Sperry (1860-1930), first came into use with reference to automobiles in 1898. History The automotive industry began in the 1860s with hundreds of manufacturers that pioneered the horseless carriage. For many decades, the United States led the world in total automobile production. In 1929, before the Great Depression, the world had 32,028,500 automobiles in use, and the U.S. automobile industry produced over 90% of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Broken Fuel Pipe
Broken may refer to: Literature * ''Broken'' (Armstrong novel), a 2006 novel by Kelley Armstrong in the ''Women of the Otherworld'' series * ''Broken'' (Slaughter novel), a 2010 novel by Karin Slaughter Music Albums * '' Broken (And Other Rogue States)'', a 2005 album by Luke Doucet * ''Broken'' (MBLAQ EP) (2014) * ''Broken'' (Nine Inch Nails EP), (1992) * ''Broken'' (Soulsavers album) (2009) * ''Broken'' (Straight Faced album) (1996) Songs * "Broken" (Jake Bugg song) (2013) * "Broken" (Sam Clark song) (2009) * "Broken" (Coldplay song) (2019) * "Broken" (Elisa song) (2003) * "Broken" (Lifehouse song) (2008) * "Broken" (lovelytheband song) (2017) * "Broken" (Kate Ryan song) (2011) * "Broken" (Seether song) (2004) * "Broken" (Slander and Kompany song) (2019) * "Broken", by 12 Stones from '' 12 Stones'' * "Broken", by All That Remains from ''Victim of the New Disease'' * "Broken", by David Archuleta from '' Begin'' * "Broken", by Bad Religion from ''The Pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stress–strain Curve
In engineering and materials science, a stress–strain curve for a material gives the relationship between stress and strain. It is obtained by gradually applying load to a test coupon and measuring the deformation, from which the stress and strain can be determined (see tensile testing). These curves reveal many of the properties of a material, such as the Young's modulus, the yield strength and the ultimate tensile strength. Definition Generally speaking, curves representing the relationship between stress and strain in any form of deformation can be regarded as stress–strain curves. The stress and strain can be normal, shear, or mixture, also can be uniaxial, biaxial, or multiaxial, even change with time. The form of deformation can be compression, stretching, torsion, rotation, and so on. If not mentioned otherwise, stress–strain curve refers to the relationship between axial normal stress and axial normal strain of materials measured in a tension test. Engin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SABIC
Saudi Basic Industries Corporation ( ar, الشركة السعودية للصناعات الأساسية), known as SABIC ( ar, سابك), is a Saudi chemical manufacturing company. 70% of SABIC's shares are owned by Saudi Aramco. It is active in petrochemicals, chemicals, industrial polymers, fertilizers, and metals. It is the second largest public company in the Middle East and Saudi Arabia as listed in Tadawul. In 2017, SABIC was ranked fourth in the world among chemical companies by Fortune Global 500. By the end of 2018 SABIC was the world's 281st-largest corporation. In 2014, the company had sales revenues of $50.4 billion, profits of $6.7 billion and assets standing at $90.4 billion. It also has been recognized as the world's second most valuable brand in the chemicals industry by Brand Finance in 2021. History SABIC was founded in 1976 by royal decree to convert oil by-products into useful chemicals, polymers, and fertilizers. The first chairman of the company was Gha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fracture Mechanics
Fracture mechanics is the field of mechanics concerned with the study of the propagation of cracks in materials. It uses methods of analytical solid mechanics to calculate the driving force on a crack and those of experimental solid mechanics to characterize the material's resistance to fracture. Theoretically, the stress ahead of a sharp crack tip becomes infinite and cannot be used to describe the state around a crack. Fracture mechanics is used to characterise the loads on a crack, typically using a single parameter to describe the complete loading state at the crack tip. A number of different parameters have been developed. When the plastic zone at the tip of the crack is small relative to the crack length the stress state at the crack tip is the result of elastic forces within the material and is termed linear elastic fracture mechanics (LEFM) and can be characterised using the stress intensity factor K. Although the load on a crack can be arbitrary, in 1957 G. Irwin fou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diffusion
Diffusion is the net movement of anything (for example, atoms, ions, molecules, energy) generally from a region of higher concentration to a region of lower concentration. Diffusion is driven by a gradient in Gibbs free energy or chemical potential. It is possible to diffuse "uphill" from a region of lower concentration to a region of higher concentration, like in spinodal decomposition. The concept of diffusion is widely used in many fields, including physics ( particle diffusion), chemistry, biology, sociology, economics, and finance (diffusion of people, ideas, and price values). The central idea of diffusion, however, is common to all of these: a substance or collection undergoing diffusion spreads out from a point or location at which there is a higher concentration of that substance or collection. A gradient is the change in the value of a quantity, for example, concentration, pressure, or temperature with the change in another variable, usually distance. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wetting
Wetting is the ability of a liquid to maintain contact with a solid surface, resulting from intermolecular interactions when the two are brought together. This happens in presence of a gaseous phase or another liquid phase not miscible with the first one. The degree of wetting (wettability) is determined by a force balance between adhesive and cohesive forces. Wetting is important in the bonding or adherence of two materials. Wetting and the surface forces that control wetting are also responsible for other related effects, including capillary effects. There are two types of wetting: non-reactive wetting and reactive wetting. Wetting deals with three phases of matter: gas, liquid, and solid. It is now a center of attention in nanotechnology and nanoscience studies due to the advent of many nanomaterials in the past two decades (e.g. graphene, Carbon nano tube, carbon nanotube, boron nitride nanomesh). Explanation Adhesive forces between a liquid and solid cause a liqu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glass Transition Temperature
The glass–liquid transition, or glass transition, is the gradual and reversible transition in amorphous materials (or in amorphous regions within semicrystalline materials) from a hard and relatively brittle "glassy" state into a viscous or rubbery state as the temperature is increased. ISO 11357-2: Plastics – Differential scanning calorimetry – Part 2: Determination of glass transition temperature (1999). An amorphous solid that exhibits a glass transition is called a glass. The reverse transition, achieved by supercooling a viscous liquid into the glass state, is called vitrification. The glass-transition temperature ''T''g of a material characterizes the range of temperatures over which this glass transition occurs (as an experimental definition, typically marked as 100 s of relaxation time). It is always lower than the melting temperature, ''T''m, of the crystalline state of the material, if one exists. Hard plastics like polystyrene and poly(methyl methacrylate) a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
