General plasticizers

Generally, plastics have excellent resistance to weak mineral acids and are unaffected by inorganic salt solutions—areas where metals are not entirely suitable. Since plastics do not corrode in the electrochemical sense, they offer another advantage over metals most metals are affected by slight changes in pH, or minor impurities, or oxygen content, while plastics will remain resistant to these same changes. 

In pre-cracked structures these processes determine the fatigue life. In uncracked components subject to low-cycle fatigue, the general plasticity quickly roughens the... 

In general, plastics have a higher density when they crystallise due to the closer packing of the molecules. Typical characteristics of crystalline and amorphous plastics are shown below. 

Little comprehensive work has been carried out on contact corrosion, but some results on a range of polymers have been reported by Czech workers". In general, plastics that give rise to vapour corrosion (Table 18.18) will also cause contact corrosion. Some qualification is needed to this statement, however, as much depends on the type of contact and the other ingredients in the polymer, e.g. a paint may give good protection to the metal to which it is applied, but the vapour may cause corrosion of adjacent metal items within an enclosed space. 

Radiation In general, plastics are superior to elastomers in radiation resistance but are inferior to metals and ceramics. The materials that will respond satisfactorily in the range of I010 and 10n erg per gram include... 

Fig. 9-2 A general plastic cost comparison, based on volume, for a general classification of materials.

G. Therefore, in a polycrystal, the macroscopic stress needed general plastic deformation is ... 

Last-A-Foam Plastic foam General Plastics... 

Hagai, T Eyehd bums A general plastic surgeon s approach. In Hornblass, A. (ed.) Oculoplastic, Orbital and Reconstractive Surgery pp. 448 54. Williams Wilkins, Baltimore (1988)... 

Materials used for insulating sheaths should be inert and easy to machine they are generally plastics or casting epoxy resins. Epoxy resins are easier to handle because of their moulding ability but they are not chemically inert to certain species, including many non-aqueous solvents. Additionally, care must be taken when preparing the epoxy resins that air bubbles do not appear in the mixture prior treatment of the adhesive and hardener mixture under vacuum for a short while reduces the problem. 

Plastics. Polypropylene is inexpensive and is most popular when temperatures do not exceed 250°F. Caution is required where hot spots are likely, e.g., due to heat of solution. Other plastics may be better for higher temperatures, but these tend to be more expensive. Generally, plastic Pall rings are stiffer and resist softening more than other shapes because of their internal "arms. ... 

In general, plastics are superior to elastomers in radiation resistance but are inferior to metals and ceramics. The materials that will respond satisfactorily in the range of 1010 and 1011 erg per gram are glass and asbestos-filled phenolics, certain epoxies, polyurethane, polystyrene, mineral-filled polyesters, silicone, and furane. The next group of plastics in order of radiation resistance includes polyethylene, melamine, urea formaldehyde, unfilled phenolic, and silicone resins. Those materials that have poor radiation resistance include methyl methacrylate, unfilled polyesters, cellulosics, polyamides, and fluorocarbons. 

Molding Materials (alternative materials of general plastics)... 

Pilot (400 t/y) in Okegawa City (J) for general plastic waste Demonstration (5000 t/y) in Aioi City (J) for industrial plastic waste... 

Generally, plastic baking shortenings should be firm and plastic, but not brittle or too soft and oily. Hardfat is added to soybean oil to achieve proper texture, plasticity, and creaming properties. Plastic shortenings should be soft and plastic at low temperatures and still remain semisolid at body temperature. 

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