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Fatigue resistance, degradation

The fluorine content of II gives it excellent resistance to fuels, oils, most hydraulic fluids and chemicals. Since there are no C-C and C-H bonds along the polymer backbone, II displays excellent resistance to degradation by atmospheric oxygen and ozone. Tn addition, the Inherently flexible nature of the P-N backbone allows this elastomer to be used at temperatures down to -65°C, and gives the polymer excellent flex fatigue resistance over a broad temperature range (-65 to 175°C). [Pg.279]

Polyethers. Acetal Resins. These stabilized polyoxymethy-lenes were introduced dramatically by DuPont and Celanese as engineering plastics to replace non-ferrous metals. Good mechanical strength, resilience, fatigue-resistance, lubricity, abrasion-resistance, heat distortion temperature, water and solvent-resistance can approach the behavior of metals on a volume basis, while processability, color possibilities, and corrosion-resistance are superior. Major weakness is sensitivity to thermal, oxidative, and ionic degradation. [Pg.22]

Nylon 6, or nylon caprolactam, is a polymeric fiber derived from only one constituent, caprolactam, giving the polymer [-(CH2)5CONH-] . It has a lower melting point than nylon 6,6, but it is superior to it in resistance to light degradation, elastic recovery, fatigue resistance, and thermal stability. [Pg.411]

Spirooxazines have excellent resistance to light-induced degradation. This property, also called fatigue resistance, is considered to be due to photochemical stability of the oxazine molecule framework in the ring-closed form as well as in the open-ring form. The fatigue resistance of the spirooxazines has led to then-successful use in various applications, for example, eyewear. [Pg.86]

For kinetic data acquisition, the desired number of points, the sampling step (100ns-Is), and the number of degradation cycles before measurements are entered. At the end of the experiment, the fatigue resistance time tR (time at which the initial absorbance value A0 is reduced by half) is calculated by interpolation. [Pg.149]

In the continuous degradation mode B, the input time sequences and parameters are the same as in the cyclic mode except for the darkness duration, which is reduced to one minute, i.e., the time required to stabilize the PMT. The fatigue resistance tR is calculated as for mode A. [Pg.149]

The flash degradation mode C requires a preset number n of flashes followed by one measuring flash, with the input being the number of degradation flashes and sequences. The fatigue resistance is now defined as the number of flashes needed to reach A0/2. [Pg.149]

Alloying for improved mechanical properties can improve strength, toughness, and fatigue resistance. Such steels are normally heat treated to enhance their properties. Welding these alloys can degrade them. [Pg.1553]

Oxidation of elastomers is accelerated by a number of factors including heat, heavy metal contamination, sulfur, light, moisture, swelling in oil and solvents, dynamic fatigue, oxygen, and ozone. Three variables in the compound formulation can be optimized to resist degradation polymer type, cure system,... [Pg.444]

The features required for each of these applications can be very different depending on the site of implant, length of implantation, method of application, and function. For this reason, a large variety of biomedical-grade PUs with different compositions have been produced and marketed (Table 12.2). These products differ in terms of elastomeric properties, degradation rate, hydrophilicity, fatigue resistance, resistance to stress cracking, and so on. [Pg.351]


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See also in sourсe #XX -- [ Pg.961 ]




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Degradation resistance

Degradation resistant

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