Search Results for water absorption

This article provides an overview of the physics and math associated with moisture-related failures in plastic components. It develops key equations, showing how they are used to analyze the causes and effects of water uptake, diffusion, and moisture concentration in polymeric materials and resins. It explains how absorbed moisture affects a wide range of properties, including glass transition temperature, flexural and shear modulus,creep, stress relaxation, swelling, tensile and yield strength, and fatigue cracking. It provides relevant data on common polymers, resins, and fiber-resin composites.

Natural and synthetic rubber linings are used extensively in many industries for their corrosion and/or abrasion resistance. These industries include transportation, chemical processing, water treatment, power, mineral processing, and mining. This article provides information on soft natural rubber, semihard natural rubber, hard natural rubber, neoprene or polychloroprene, chlorobutyl, three-ply linings, nitrile, and ethylene propylene with a diene monomer. Emphasis is placed on advantages, disadvantages, and common uses of each material discussed.

This article provides a discussion on various types of glasses: traditional glasses, specialty glasses, and glass ceramics. It provides information on glazes and enamels and reviews the broad classes of ceramic materials. These include whitewares, structural clay products, technical ceramics, refractories, structural ceramics, engineering ceramics, and electronic and magnetic ceramics. General processing variables that can affect structure and compositional homogeneity are discussed. Traditional ceramics that include both oxide and nonoxide ceramics are also reviewed. The article concludes with several examples of engineering ceramics.

Traditional ceramics, one of two general classes, are commonly used in high-volume manufacturing to make building materials, household products, and various industrial goods. Although there is a tendency to equate traditional ceramics with low technology, sophisticated processes and advanced manufacturing techniques are often used where these materials are employed. This article examines several traditional ceramics, including structural clay, whiteware, glazes, enamels, portland cements, and concrete. It also provides a detailed account of fabrication methods, properties, and applications. As an example, common applications for structural clay include facing materials, load-bearing units, pavers, and ceramic tiles.

Bitumen for coating usage can best be categorized as two fundamental but very different types: asphalts and coal tars. This article provides a detailed discussion on asphalt and coal tar hot-melt applications; asphalt and coal tar emulsions; asphalt and coal tar cutbacks; and coal tar epoxies. It reviews the similarities between asphaltic and coal tar coatings and discusses the health and environmental concerns of these materials.

Thermal analysis provides a powerful tool for researchers and engineers in determining both unknown and reproducible behavioral properties of polymer molecules. This article covers the thermal analysis and thermal properties of engineering plastics with respect to chemical composition, chain configuration, conformation of the base polymers, processing of the base polymers with or without additives; and the response to chemical, physical, and mechanical stresses of base polymers as unfilled, shaped articles or as components of composite structures. It also describes thermal analysis techniques, including differential scanning calorimetry, thermogravimetric analysis, thermomechanical analysis, and rheological analysis. This article also summarizes the basic thermal properties used in the application of engineering plastics, such as thermal conductivity, temperature resistance, thermal expansion, specific heat, and the determination of glass transition temperatures. It concludes with a discussion of the thermal and related properties of nine thermostat resin systems divided into three groups by low, medium, and high service temperature capabilities.

Polyvinylidene fluoride (PVDF)-based coatings are typically used in outdoor applications that require exceptionally high performance and excellent long-term exterior durability with little maintenance. This article provides a background of three fluoropolymers most commonly used for coatings, namely, PVDF, polyvinyl fluoride, and polytetrafluoroethylene. It focuses on general properties, polymerization, resin types, coating formulation, technology of organic coatings, coating properties, and health and related safety considerations of PVDF. The article describes the application and typical end uses of PVDF-based coatings and the opportunities for improvement in PVDF-based coatings as with all organic coatings.

Ultraviolet/visible (UV/VIS) absorption spectroscopy is a powerful yet cost-effective tool that is widely used to identify organic compounds and to measure the concentration of principal and trace constituents in liquid, gas, and solid test samples. This article emphasizes the quantitative analysis of elements in metals and metal-bearing ores. The instrumentation required for such applications consists of a light source, a filter or wavelength selector, and some type of visual or automated sensing mechanism. The article examines common sensing options and provides helpful information on how to set up and run a variety of UV/VIS absorption tests.

This article discusses the thermal properties of engineering plastics and elastomers with respect to chemical composition, chain configuration, and base polymer conformation as determined by thermal analysis. It describes the processing of base polymers with or without additives and their response to chemical, physical, and mechanical stresses whether as an unfilled, shaped article or as a component of a composite structure. It summarizes the basic thermal properties of thermoplastics and thermosets, including thermal conductivity, temperature resistance, thermal expansion, specific heat, and glass transition temperature. It also provides information on polyimide and bismaleimide resin systems. Representative examples of different types of engineering thermoplastics are discussed primarily in terms of structure and thermal properties.

Hygrothermal behavior of cured composite materials relates to the combined and commonly synergistic effects of moisture absorption and temperature on various physical, chemical and mechanical properties. This article focuses on the influence of resins or matrices, reinforcements, processing, and diffusion on hygrothermal behavior of polymer-matrix composites and provides an outline on general considerations in assessing them. It discusses the hygrothermal testing and conditioning of polymer-matrix composites to assess fundamental hygrothermal behavior. The article provides information on the accelerated aging process for understanding the degradation mechanisms and failure modes in composites. It also describes the effect of moisture absorption on mechanical properties of polymer-matrix composites.

Honeycomb is a product consisting of very thin sheets attached to form connecting cells. This article briefly explains the construction, core characteristics, properties, and testing methods of the honeycomb structures. It discusses the special processes carried out in customizing the shape of core to fit customer's specific needs. The article provides information on the basic concept of creating sandwich structures and its corresponding aspects like material selection, design guidelines, and structural efficiency.