Strength retention

This treatment produced a fabric with durable flame resistance and good strength retention, but an undesirable afterglow this was eliminated by phosphorylation with diethyl chlorophosphate [814-49-3]. 

In order to achieve the desired fiber properties, the two monomers were copolymerized so the final product was a block copolymer of the ABA type, where A was pure polyglycoHde and B, a random copolymer of mostly poly (trimethylene carbonate). The selected composition was about 30—40% poly (trimethylene carbonate). This suture reportedly has exceUent flexibiHty and superior in vivo tensile strength retention compared to polyglycoHde. It has been absorbed without adverse reaction ia about seven months (43). MetaboHsm studies show that the route of excretion for the trimethylene carbonate moiety is somewhat different from the glycolate moiety. Most of the glycolate is excreted by urine whereas most of the carbonate is excreted by expired CO2 and uriae. 

Sihcon nitride has good strength retention at high temperature and is the most oxidation resistant nitride. Boron nitride [10043-11 -5] has excellent thermal shock resistance and is in many ways similar to graphite, except that it is not an electrical conductor. 

Fig. 2. Tensile strength retention, continuous service, for fluorocarbon elastomers. Compound I (see Table 4).

Effect of corrosion inhibiting primer on strength retention after exposure to salt spray [29]... 

Long term strength retention of glass fiber in wet service... 

Table 8-42 Percent tensile strength retention using welding techniques... 

For properties such as peel strength and elongation to break, which decrease with oxidation, a different empirical relation has to be used. We have found that elongation to break and peel strength retention data can be fit to the following expression [15] ... 

FIGURE 34.9 Peel strength retention for skim rubber (center) versus week in Phoenix for SUV/Minivan-A tire. 

A. Skim Peel Strength Retention Rate Constant (Center), p, weeks... 

Reagent Retention of tensile strength (%) Retention of FS (%) Retention of EBC (%) Appearance Performance Retention of tensile strength (%) Retention of FS (%) Retention of EBC (%) Appearance Performance... 

Figure 4.59 displays examples of tensile strength retention versus short-term temperature increase for neat, glass fibre (GF) and glass bead (GB) PA 12 grades. 

Figure 4.59. PA 12 examples of tensile strength retention (%) versus temperature (°C)...

The short-term modulus or tensile strength retention at 120°C as a percentage of the value at 20°C is roughly 30-50% for a few glass fibre reinforced grades. 

Figure 4.98 displays an example of tensile strength retention versus temperature for a neat polyethersulfone. Note the slow decay considering the high temperatures and the significant value of 35% for the retention at 200°C, that is, 30 MPa. 

The resistance to moisture and hot water is good without hydrolysis but the resistances of glass fibre reinforced compounds can decrease significantly because of polymer/fibre interface alterations. For example, after 1 year in water at 120°C, tensile strength retention is 50% for a given compound. However, special grades with improved hot-water resistance are marketed and are successfully used in hot-water pumps. 

Figure 4.105 displays two examples of tensile strength retention versus temperature for a neat and a carbon fibre reinforced polyetherketone, showing the rather fast decay up to 180°C followed by a stabilization. 

The resistance to gamma radiation is good without significant degradation after 500 Mrad tensile strength retention is 94%. 

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