Polymeric materials useful lifetime

Polymeric materials are intrinsically expensive, but their use becomes appealing if one takes into account the processing costs, the new technical possibilities that they permit and the total cost at the end of their lifetime. 

For example, Song et al [209] described three methods for predicting the long-term mechanical behavior and lifetime of polymeric materials based on the detailed analysis and interpretation of experimental data. They used semicrystalline, glassy amorphous and rubbery polymers as examples in validating these methods. The three methods are the following ... 

The prediction of the useful lifetime of polymer materials is a major challenge for the industry. New research efforts have been focused to understand the complex mechanism of polymer degradation by analyzing the chemiluminescence emission, due to its capabilities as well as commercially developed instrumentation. In the next few years, it would be expected that chemiluminescence will earn a place as a well-established research technique in many laboratories, and will contribute to the better understanding of the molecular structural level and the relationship with the macroscopic properties and the behavior in the use of the polymeric materials. 

Production and uses of textiles and polymeric materials SCCPs and LCCPs Washoff of coatings abrasive losses 0.05% over their lifetime... 

UV radiation originating from sunlight or artificial light sources results in substantial degradation of many commercial polymeric substrates. Degradation manifested as discoloration, embrittlement, cracking, and loss of other physical properties seriously reduces the useful lifetime and potential applications of polymeric materials. 

The term compatibihzing was defined by Gaylord in 1966 (133) as rendering a mixture of two or more polymeric materials permanently miscible so as to form a homogeneous composition that has useful plastic properties and which does not separate into its component parts. Actually, in his definition the term miscible was not appropriate and another term uniform would be better. A few years later, he defined another term compatibilization as absence of separation or stratification of the components of the polymeric alloy during the expected useful lifetime of the product (134). 

Chapter 3 describes the various components of plastics and how they are transformed into three-dimensional functional solids. The chapter is not intended as a technical manual from which polymers can be synthesized and plastics prepared but as an overview of selected procedures and materials relevant to museum professionals concerned with plastics. Knowledge of plastics technology helps to date plastics objects, to interpret chemical analysis of plastics and to understand the causes of deterioration. Polymerization, additives and shaping processes contribute to the physical and chemical properties, useful lifetime and degradation pathways of plastics. The optical, chemical and physical properties of plastics are detailed in Chapter 4. 

It is relatively easy to mechanically test components to failure in the laboratory. Testing specifications and standards are laid down for the mechanical behaviours of components immediately after manufacture. However, as discussed in the previous chapter, it is unsafe to assume that these will remain unchanged over the lifetime of the component since the durability of a polymeric materials depends on its structure, on the environment in which it is used and on the stabilisation system used. 

The use of proton conductors in ECDs is very attractive since the proton is the smallest ion and can rapidly diffuse into WO3. However, the attempts made with hydrated materials lead either to gas evolution at the electrochromic/electrolyte interface or to the degradation of the electro-chromic layer leading to a poor lifetime of the cell. The discovery of polymeric materials, free from water, has opened a new area of research into ECDs with proton conductors. It has now been ascertained that a variety of polymer electrolytes may be obtained. However, the polymer complexes have generally a conductivity in the range (fl.cm) S... 

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