Other types of nylon

After it was verified that nylon 6 could be mixed with clay to make nanocomposites with dramatically improved performance characteristics, the same synthesis techniques were applied to other types of nylon resins. 

16 Schematic depicting the compounding process for preparing nanocomposites using a clay slurry. 

Specimen Clay content (%) Tensile strength (MPa) Tensile modulus (GPa) Heat distortion temperature (°C at18.5kg/cm) 

10-diaminodecane and 1,10-decanedicarboxylic acid were polycondensed in the presence of an organophilic clay to form a nylon 10,12-clay nanocomposite. X-ray diffraction and TEM observations revealed that the clay layers were exfoliated and uniformly dispersed in nylon 10,12. The speed of crystallization of the nanocomposite was higher than that of nylon 10,12. Furthermore, the tensile strength and the elastic modulus in tension were improved, and the amount of absorbed water was decreased through improvement of the nanocomposite s barrier characteristics. 

A nylon 11-clay nanocomposite was prepared using the melt compounding method. X-ray diffraction and TEM observations showed that this technique formed an exfoliated nanocomposite at low concentrations of clay (less than 4wt.%) and that a nanocomposite with both exfoliated and intercalated clay layers was formed at high clay concentrations. TGA, DMA and tensile tests showed that the thermal stability and mechanical properties of the exfoliated nanocomposite were superior to those of the intercalated nanocomposite material (with higher clay content). The superior thermal stability and mechanical properties of the exfoliated nanocomposite were attributed to the organophilic clay being dispersed stably and densely in the nylon 11 matrix. 

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The resulting hexarnethylenediarnine can then be reused to produce new nylon-6,6. Impurities or contaminants from monomers of other types of polyamides can be readily removed by distillation from either the nitriles or diamine. 

Plastics, such as PE, PP, polystyrene (PS), polyester, and nylon, etc., and elastomers such as natural rubber, EPDM, butyl rubber, NR, and styrene butadiene rubber (SBR), etc., are usually used as blend components in making thermoplastic elastomers. Such blends have certain advantages over the other type of TPEs. The desired properties are achieved by suitable elasto-mers/plastic selection and their proportion in the blend. 

Polyamides (nylons) The main types of nylon are oil and petrol resistant, but on the other hand susceptible to high water absorption and to hydrolysis. There are a few solvents such as phenol, cresol and formic acid. Special grades include a water-soluble nylon, amorphous copolymers and low molecular weight grades used in conjunction with epoxide resins. Transparent amorphous polyamides are also now available. 

NYLON. [CAS 63428-83-1], ( VI I NO), Generic name for a family of polyamide polymers characterized by lire presence of llie amide group —CONH. By far the most important are nylon 66 (75% of U.S. consumption i and nylon 6 (25% of U.S. consumption). Except for slight difference in melting points, the properties of the two forms are almost identical, though their chemical derivations are quite different. Other types are nylons 4, 9, 11, and 12. 

More than 1 million tons of nylon is produced annually in the United States for use in clothing, carpets, rope, and so on. Many other types of condensation polymers are also produced. For example, Dacron is a copolymer formed from the condensation reaction of ethylene glycol (a dialcohol) and p-terephthalic acid (a dicarboxylic acid) ... 

Other materials in waste that is thermally processed also were studied by pyrolytic techniques, typically with the purpose of regenerating the monomers or of obtaining other useful small molecules. For example, pyrolytic studies were performed for the evaluation of the possibilities for re-utilization of nylon carpet waste [7], the recycling of thermoset polymeric composites [8], the recovery of methyl methacrylate from poly(methyl methacrylate) waste [9], as well as for other raw material recovery from pyrolysis of plastic waste [10]. The results of incineration of various other types of waste also were studied at model scale [11, 12). These studies were applied to specific waste materials associated with the manufacturing process or to municipal solid waste [13-15)... 

The chemistry of protein fibres, especially that of wool, is more complex than that of most other types of fibre. The amide groups which link the repeat units are also to be found in nylon fibres. Amides can be cleaved hydrolytically by strong acids and bases. However, the inter- and intramolecular bonds in wool are particularly numerous. There are hydrogen and disulphide bonds, salt links and hydrophobic attraction. All of these bonds are important for understanding chemical damage to wool and the possibilities for its detection. 

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