Properties of nylon

The pelargonic acid by-product is already a useful item of commerce, making the overall process a commercial possibiUty. The 13-carbon polyamides appear to have many of the properties of nylon-11, nylon-12, or nylon-12,12 toughness, moisture resistance, dimensional stabiUty, increased resistance to hydrolysis, moderate melt point, and melt processibiUty. Thus, these nylons could be useful in similar markets, eg, automotive parts, coatings, fibers, or films. Properties for nylon-13,13 are = 56 (7 and = 183 (7 (179). 

Tensile Properties. Tensile properties of nylon-6 and nylon-6,6 yams shown in Table 1 are a function of polymer molecular weight, fiber spinning speed, quenching rate, and draw ratio. The degree of crystallinity and crystal and amorphous orientation obtained by modifying elements of the melt-spinning process have been related to the tenacity of nylon fiber (23,27). 

Table 1. Tensile Properties of Nylon-6 and Nylon-6,6 Continuous-Filament Yams...

To accommodate the various uses in 100% form and in blends, the tenacities and elongations of the nylon staple offerings range from 0.3 to 0.6 N /tex (3—7 g/den) and from 50 to 100% elongation. Most other fiber properties of nylon staple differ tittle from those of the continuous filament property characteristics of nylon-6 and nylon-6,6 are similar (see Polyamides, general). 

Fig. 11. Effect of spinning speed on properties of nylon-6 fibers, where (T) is the tangent modulus (° ), the tenacity and (A ), the elongation. To convert...

Table 18.6 Effect of conditioning on selected mechanical properties of nylon 46 (Conditioning according to ISO 1110 accelerated method 70 C/62% RH. All measurements at 23 C)...

Okada, A., Kawasumi, M., Usuki, A, Kojima, Y., Kurauchi, T. and Kamigaito, 0.1990. Synthesis and properties of nylon-6/clay hybrids. In Schaefer DW, Mark ]E. eds. Polymer based molecular composites. Pittsburgh. MRS Symposium Proceedings 171 45-50. 

Nylon-6-clay nanocomposites were also prepared by melt intercalation process [49]. Mechanical and thermal testing revealed that the properties of Nylon-6-clay nanocomposites are superior to Nylon. The tensile strength, flexural strength, and notched Izod impact strength are similar for both melt intercalation and in sim polymerization methods. However, the heat distortion temperature is low (112°C) for melt intercalated Nylon-6-nanocomposite, compared to 152°C for nanocomposite prepared via in situ polymerization [33]. 

We can manipulate the properties of nylon products by changing the conditions under which we crystallize them. The degree of crystallinity is increased by slow cooling, annealing, and by crystallization from highly oriented melts. As we increase the crystallinity level, stiffness and yield strength increase at the expense of impact strength. 

Y. Ou, F. Yang, J. Chen, Interfacial interaction and mechanical properties of nylon 6-potassium titanate composites prepared by In-situ polymerization, Journal of Applied Polymer Science, vol. 64, pp. 2317-2322,1998. 

TABLE 4.5 General Physical Properties of Nylon 6,6 and Nylon 6 ... 

Table 4.5 contains general physical properties of nylon 6,6 and nylon 6. As expected, they are similar. 

Polymer-clay nanocomposites (PCN) are a class of hybrid materials composed of organic polymer matrices and organophilic clay fillers, introduced in late 1980s by the researchers of Toyota (Kawasumi, 2004). They observed an increase in mechanical and thermal properties of nylons with the addition of a small amount of nano-sized clays. This new and emerging class of pol miers has found several applications in the food and non-food sectors, such as in constmction, automobiles, aerospace, military, electronics, food packaging and coatings, because of its superior mechanical strength, heat and flame resistance and improved barrier properties (Ray et al., 2006). 

Acrylonitrile is reported to change properties of Nylons by grafting (14,18, 20,21,37,58,62). It is worthwhile to call the attention to Hargreaves work who studied extensively the subject. A 25% solution of acrylonitrile in a 15% solution of zinc chloride was used as immersion media. A flow diagram for radiation polymerization of liquid material is presented (27). 

In past studies (3), Electron Spin Resonance, ESR, has been used to investigate bond rupture associated with stress-ozone degradation in unsaturated rubbers. It was believed that it might be enlightening to perform similar experiments on plastics ( 5, 8, 10, 11). In the study reported here the combined effects of environment (O3, N02 and S02) and sustained stress on the ultimate properties of Nylon 6 fibers are presented. These agents were found to have a profound effect on strength, toughness and the deformation-bond rupture kinetics. 

A synergistic effect between the role of stress and environmental agents such as O3, SO2 and NO2 on degradation of the mechanical properties of Nylon fibers has been observed. This... 

Effect of Clays on Physical and Flammability Properties of Nylon 6 Fibers/Fabrics Prepared from Samples Given in Table 24.5... 

The chemical and physical properties of nylons have been extensively described (76). Nylon will not support mildew or bacteria. Moth larvae may bite their way through nylon if imprisoned. In soil burial tests, it was found that nylon 6 retained more than 95% of its strength after six months. By contrast, wool and cotton were rotten after one month (3). Nylon may be affected by chlorine bleach, and strong oxidizing bleaches can damage it (31). 

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