Performance of Plastics

Nakazaki, Y. Ishikawa, A. Izuoka, T Sugawara, and Y. Kawada, Chem. Phys. Lett. 319, 385-390 (2000). 

On top of the above attributes, polymer materials are generally less expensive than most alternative materials. Mechanical properties are most important in the design and selection of engineering plastics because all applications require necessarily a certain degree of mechanical loading. 

Consider now polymer-based materials from the point of view of a materials user. A user can be an industrialist who buys truckloads of polymer-based components for his plant, a housewife, a little girl playing with a plastic doll—in fact anybody. The user typically has no interest (and little knowledge) of chemical synthesis of polymers, thermodynamics, polymer processing— in fact of any of the areas of polymer science and engineering. There is only one aspect of interest 

Problems in polymer science and engineering can be solved on the basis of information acquired in experiments, by developing models and theories, and also by performing computer simulations. All these three kinds of approaches are useful when dealing with performance and reliability. 

Relaxational and Destructive Processes Chain Relaxation Capability 

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Flammability. The results of small-scale laboratory tests of plastic foams have been recognized as not predictive of their tme behavior in other fire situations (205). Work aimed at developing tests to evaluate the performance of plastic foams in actual fire situations continues. All plastic foams are combustible, some burning more readily than others when exposed to fire. Some additives (131,135), when added in small quantities to the polymer, markedly improve the behavior of the foam in the presence of small fire sources. Plastic foams must be used properly following the manufacturers recommendations and any appHcable regulations. 

VINCENT, p. I., Impact Tests and Service Performance of Plastics, Plastics Institute, London (1971)... 

Wool, R.P., Interfaces and adhesion. In Brostow, W. (Ed.), Performance of Plastics. Hanser/Gardner Publishers, Munich, 2000, chapter 15. 

Permeability. The low density of plastics is an advantage in many situations but the relatively loose packing of the molecules means that gases and liquids can permeate through the plastic. This can be important in many applications such as packaging or fuel tanks. It is not possible to generalise about the performance of plastics relative to each other or in respect to the performance of a specific plastic in contact with different liquids and gases. 

One general method of improving the performance of plastic products in impact loading is to prevent, by design and handling, the formation of notched areas which act as stress... 

Material and process interaction and their effects on the performance of plastic products are important factors for the designer to understand. It can result in design limitations such as a selected material meeting performance requirements but not pro-cessible by the desired method of fabrication. Most of the limitations that are reviewed in this book can be corrected and do not effect the product performances when qualified people handle the limitations. However they are presented to reduce or eliminate potential problems. 

Avoiding product failures can depend, in part, on the ability to predict the performance of plastic materials and their shapes. With available time, the usual approach of product prototype and/or field-testing provides useful and reliable performance data when conducted properly. As an example designers continue to develop sophisticated computer methods for calculating stresses in complex structures. 

There are destructive and nondestructive tests (NDTs) (2). Most important, they are essential for determining the performance of plastic materials to be processed and of the finished fabricated products. Testing refers to the determination by technical means properties and performances. This action, when possible, should involve application of established scientific principles and procedures. It requires specifying what requirements are to be met. There are many different tests (thousands) that can be conducted that relate to practically any material or product requirement. Usually only a few will be applicable to meet your specific application. Examples of these tests will be presented. 

Of historical interest may be the use of a half dollar coin (the lighter weight 250 not as efficient). During the early 1940s the coin tap test was used very successfully in evaluating the performances of plastics, particularly RP primary aircraft structures. With a good ear (human hearing ear) there was (and is) a definite different sound between a satisfactory and unsatisfactory RP product. The unsatisfactory product would contain voids, delaminations, defects in fiber distribution, etc. In... 

Processing conditions influence the performance of plastics. For example, heating a crystalline material above its melting point, then quenching it can produce a plastic that has a far more amorphous structure. Its properties can be significantly different than if it is cooled properly (slowly) and allowed to recrystallize during processing it becomes amorphous. The effects of time are similar to those of temperature in the sense that any... 

Performance of plastics , W. Brostow Hanser Gardner Pubis (1999) ISBN 1569902771. Comprehensively covers the behavior of the most important polymer materials. Subject areas range from Computer Simulations of Mechanical Behavior to Reliability and Durability of aircraft structures made of fiber-reinforced hydrocarbons. 

Mathematical Modeling of Forming and Performance of Plastic Materials... 

Analysis of realistic aspects of fabrication and performance of plastic materials involves the combination of complex geometrical, material and physical factors. The identification of the material mechanisms responsible for a specific phenomenon requires the development of relatively complex numerical models which accommodate the critical factors. Once the model is in place, it is possible to simulate different material mechanisms and verify their predictions through a comparison with experimental results. 

NELSON Effects of Coatings on the Fire Performance of Plastics... 

G.L. Nelson, M.L. Bosarge, K.M. Weaver, Effect of EMI Coatings on the Fire Performance of Plastics, Part II, Proceedings of the Thirteenth International Conference on Fire Safety, January 11-15, 1988, 12, 367-378 (1988). 

Test results show that thin coatings (2-5 mils) can significantly effect the fire performance of plastic substrates. Most EMI coatings decrease ignitability test results. Coatings tend to level diverse flame spread and ease of extinction performance. A 2-mil coating can reduce the 1, value in ASTM E162 Radiant... 

Brostow W. The Chain Relaxation Capability. Ch. 5. In performance of Plastics. Ed. W. Brostow, Hanser, Munich-Cincinnati, 2000. 

In point of fact, when considering the weathering performance of plastic materials, there exists even more interplay between weathering factors than the factors noted above, such as the ambient temperature, temperature of the actual specimens under exposure and the humidity during exposure of the materials. If the... 

An Austrian team boosts the performance of plastic cells by mixing a conducting polymer, MDMO-PPV (an asymmetrically substituted polyphenylenevinylene),with a molecule made from carbon fullerene. .. 

Klein, I., The Effect of Flight Clearance on the Performance of Plasticating Extruders, SPE ANTEC Tech. Papers, 20, 237 (1974)... 

Grayson, S.J. and Hirschler, M.M., Fire performance of plastics in car interiors, Flame Retardants, February 5-6, London, pp. 197-207, Interscience Communications, London, U.K., 2002. 

C.J. Brabec, S.E. Shaheen, C. Winder, N.S Sariciftci, P. Denk, Effect of LiF metal electrodes on the performance of plastic solar cells, Appl. Phys. Lett. 80 (2002) 1288. 

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