Cost-to-performance ratio

Blending is an economically viable, versatile method of manufacturing new materials with a wide range of properties [Utracki, 1987, 1993 Rauwendaal, 1986]. The parameters most frequently targeted for the improvement by blending are the mechanical properties, impact strength, processability, heat deflection temperature, and the cost-to-performance ratio. 

Performance vs. cost see Cost and Cost to performance ratio Performance vs. crystaUinity 316, 323, 725, 897, 898 see also Crystallinity... 

Major advantages of using plastics include formability, consolidation of parts, and providing a low cost to performance ratio. For the majority of applications that require only minimum mechanical performance, the product shape can help to overcome the limitations of commodity resins such as low stiffness here improved performance is easily incorporated in a process. However, where extremely high performance is required, reinforced plastics or composites are used (see Chapter 7). 

PP blends with a small amount of LCP are of industrial interest for two reasons (i) to improve processability or (ii) to improve the mechanical performance. The second effect depends on the blend s morphology, i.e., on the orientation of LCP domains. The latter depends on the concentration, viscosity and elasticity ratios, interfacial tension coefficient, fiow type and intensity, total strain, drawdown ratio, etc. Three stages of orientation are (1) drop deformatiOTi, (2) fibrillation of the domains, and (3) stretching of the LCP chains (Champagne et al. 1996). Only the latter provides a reasonable cost-to-performance ratio. Examples of PP/LCP systems are listed in Table 1.53. 

A particular answer to the demand for a low dust, low attrition, and low caking alternative to granular hydrous silicates having a favorable cost to performance ratio are the recently developed... 

Another approach is to calculate cost-to-performance ratios for diverse materials and/or compositions. For example, it may be asked how much a unit of the tensile modulus or the strength at yield will cost. Since the performance, P(wi), usually changes with composition on a logarithmic scale one can write ... 

As discussed before, the cost is determined by the material and the compounding costs. Thus the cost-to-performance ratio mainly depends on morphology tailored to the principal application of the blend. Note that the properties and composition of ingredients determine the equilibrium interphasial properties of the blend, defined by the equilibrium thermodynamics. In many commercial blends, the morphology is far from this equilibrium status. It is imposed by the method of compounding, forming and cooling. 

For larger molecules than naphthalene, SV(P) or similar basis sets are often appropriate due to their good cost-to-performance ratio. We recommend checking the SV(P) results by a TZVP calculation whenever possible. Diffuse functions should be used sparingly for molecules with more than about 20 atoms. 

A skilled compounder should be able to make use of the opportunities available in the attempt to meet the specifications of a given eompound, whieh often include conflicting requirements that must be balanced to obtain a product with optimal cost-to-performance ratio. 

Fabrics made of viscose, polyester, and polyamide (sometimes aramid) are used for the carcass. Viscose yarns have excellent adhesion to rubber and are therefore used for high-speed tires in Europe. Polyamide is mostly used for diagonal tires especially because of its cord/rubber adhesion but also because of its fatigue resistance. Polyester has been gaining market share for radial tires as a result of its excellent cost-to-performance ratio. 

For the identification of space effects on polymers, numerous standard tests must be used, namely spectroscopy, thermal analysis, dielectric and conductivity measurements, mechanical and viscoelastic property determination, etc. In the late 1990s NASA decided to substitute polyurethane coatings (having carcinogenic) with another one. The 18 alternative candidates were subjected to 34 standard test procedures (Table 3.7). In the following report the number of candidates fell to eight, from which the best with the lowest cost-to-performance ratio will have to be selected. This procedure illustrates how involved the polymeric testing for space application is, even if the test procedures are quite standard. 

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