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[...]... Comparative Corrosion Resistance of Thermoplastic and Thermoset Polymers 221 Reference 441 Chapter 5 Elastomers 5.1 Introduction 5.1.1 Importance of Compounding 5.1.2 Similarities ofElastomersand Thermoplastic Polymers 5.1.3 Differences between Elastomersand Thermoplasts 5.1.4 Causes of Failure 5.1.5 Selecting an Elastomer 5.1.6 Corrosion. .. high-performance polymers and engineering plastics According to the ASM Handbook, engineering plastics are defined as “Synthetic polymersof a resin-based material that have loadbearing characteristics and high-performance properties which permit them to be used in the same manner as metals and ceramics.” Others have limited the term to thermoplastics only Many engineeringpolymers are reinforced and/ or alloy polymers. .. long-term adhesion of the coating is affected by the properties of the polymer such as stiffness or rigidity, dimensional stability, and coefficient of expansion The physical properties of the paint film must accommodate to those of the polymer 1.5 CorrosionofPolymersCorrosionof metallic materials takes place via an electro-chemical reaction at a specific corrosion rate Consequently, the life of a metallic... & Francis Group, LLC CorrosionofPolymersandElastomers 16 5 Plasticizers and other additives Most polymers are formulated with plasticizers and chemical additives These materials have a tendency to migrate to the surface and may even soften the coating and destroy adhesion The specific polymer should be checked to determine whether the coating will cause short- or long-term softening or adhesion... cellulose were giant molecules of high molecular weight These are natural condensation polymers, and understanding their structure paved the way for the development of the synthetic condensation polymers such as polyesters, polyamides, polyimides, and polycarbonates The chronological order of the development ofpolymers is shown in Table 1.1 A relatively recent term, engineering polymers, has come into play... property and chemical resistance differences ofpolymers stem directly from the type and arrangement of atoms in the polymer chains In the periodic table, the basic elements of nature are placed into classes with similar properties, i.e., elements and compounds that exhibit similar behavior These classes are alkali metals, alkaline earth q 2006 by Taylor & Francis Group, LLC 18 CorrosionofPolymersand Elastomers. .. of thermoplastics has been greatly improved by the use of fiber reinforcement Second, has been the development of the so-called engineering or high-stability, higher-performance polymers that can be reinforced with fiber filler to increase their stability even further Third, to offset the gains in thermoplastics, lower-cost processing of 19 q 2006 by Taylor & Francis Group, LLC CorrosionofPolymers and. .. Group, LLC CorrosionofPolymersandElastomers 12 produced from the same polymer will provide an indication of the relative permeation rates The denser the sheet, the lower the permeation rate The thickness of the liner is a factor affecting permeation For general corrosion resistance, thicknesses of 0.010–0.020 in are usually satisfactory, depending on the combination of lining material and the specific... changes and large differences in coefficients of thermal expansion are the most common causes of bond failure The plastic’s thickness and modulus of elasticity are two of the factors that influence these stresses Second, as the thickness of the lining increases, installation becomes more difficult with a resulting increase in labor costs The rate of permeation is also affected by the temperature and the... temperature, and the chemical enduse environment 1.1 Additives Various properties ofpolymers may be improved by the use of additives In some instances, the use of additives to improve a specific property may have an adverse effect on certain other properties Corrosion resistance is a property most often affected by the use of additives In many cases a polymer’s corrosion resistance is reduced as a result of . editor of the Corrosion Engineering Handbook and the Corrosion and Corrosion Protection Handbook, Second Edition; and the author of Corrosion Resistance Tables, Fifth Edition; Encyclopedia of Corrosion Technology,. Resistance of Elastomers; Corrosion Resistant Piping Systems; Mechanical and Corrosion Resistant Properties of Plastics and Elastomers (all titles Marcel Dekker, Inc.), and Paint and Coatings, Applications. high-performance polymers and engineering plastics. According to the ASM Handbook, engineering plastics are defined as “Synthetic polymers of a resin-based material that have load- bearing characteristics and