Nylon types

Add 40 ml. of ethyl alcohol to 21 -5 g. of 70 per cent, ethylenediamine solution (0 -25 mol) dissolve 36 -5 g. of adipic acid (0 -25 mol) in 50 ml. of a 6 1 mixture of ethyl alcohol and water. Mix the two solutions, stir and cool. Filter off the resulting salt and recrystalliae it from 60 ml. of a 6 1 ethyl alcohol - water mixture, and dry the salt in the air. Heat the salt in an atmosphere of oxygen-free nitrogen or of carbon dioxide in an oil bath until it melts (ca. 160°) the product will sohdify after a short time. Reduce the pressure to 15 mm. of mercury or less and raise the temperature of the oil bath until the product remelts (about 290°) and continue the heating for 4r-5 hours. Upon coohng, a nylon type polymer is obtained. 

Nylon 6 and 6/6 possess the maximum stiffness, strength, and heat resistance of all the types of nylon. Type 6/6 has a higher melt temperature, whereas type 6 has a higher impact resistance and better processibility. At a sacrifice in stiffness and heat resistance, the higher analogs of nylon are useful primarily for improved chemical resistance in certain environments (acids, bases, and zinc chloride solutions) and for lower moisture absorption. 

Nylon Blends. Differential dyeiag nylon types and cationic dyeable nylon blends are used primarily ia the carpet iadustry. The selection of cationic dyes for nylon is rather limited most products have very poor fastness to light. These blends are dyed ia a one-bath procedure at 95—100°C. Selected acid dyes are used for differential dyeiag. Disperse dyes will dye all different types ia the same depth. 

Hydrocyclones are available in numerous sizes and types ranging from pencil-sized 10-mm diameters of plastic to the 1.2-m (48-in) diameter of rubber-protected mild or stainless steel. Porcelain units 25 to 100 mm (1 to 4 in) in diameter are becoming popular, and in the 150-mm (6-in) size the starch industry has standardized on special molded nylon types. Small units for fine-size separations are usually manifolded in multiple units in parallel with up to 480 ten-mm... 

There has been only one major use for ozone today in the field of chemical synthesis the ozonation of oleic acid to produce azelaic acid. Oleic acid is obtained from either tallow, a by-product of meat-packing plants, or from tall oil, a byproduct of making paper from wood. Oleic acid is dissolved in about half its weight of pelargonic acid and is ozonized continuously in a reactor with approximately 2 percent ozone in oxygen it is oxidized for several hours. The pelargonic and azelaic acids are recovered by vacuum distillation. The acids are then esterified to yield a plasticizer for vinyl compounds or for the production of lubricants. Azelaic acid is also a starting material in the production of a nylon type of polymer. 

Monomer Nylon type Monomer Formula Approximate M.P. °C ... 

The generic name given to the nylon type of polymer, which consists of short carbon chains connected by amide groups -NHCO-. See Nylon. Polybutadiene... 

The synthesis and properties of heat-resistant polyazomethines containing 2,5-disubstituted oxadiazole fragments, being insulators convertible into semiconductors by doping with iodine, have been described. The radical copolymerization of alkenes with the fluorescent co-monomer 2-/-butyl-5-(4 -vinyl-4-biphenylyl)-l,3,4-oxadiazole has resulted in useful macromolecular scintillators. Anionic polymerization of 2-phenyl-l,3,4-oxadiazolin-5-one has produced a nylon-type product <1996CHEC-II(4)268>. 

Polyamides and poljmrethanes have been the carbohydrate-based polymers most widely studied. The preparation of hydrophilic nylon-type polyamides containing... 

The retention of N02 on nylon 6 Nylasorb filters (Gelman Sciences), nylon 6 filters from Sartorius Filters, Inc., and nylon 6,6 filters from Schleicher Schuell (S S) was assessed 0.5 ppm NO was sampled at 75-80% RH and 21 °C for 6 h at 20 L/min with 47-mm filters. The results showed no more than 0.1% retention (19). Similarly, Perrino et al. observed with 47-mm Gelman Nylasorb filters (nylon type unstated) 0.4% retention, sampling 0.6 ppm NO for 15 h at 1.5 L/min and 60-80% RH (20). 

Other Interferent Studies with Nylon Filters. Retention of HONO on Gelman Nylasorb (nylon 6) filters was tested 0.3 to 1 xg/m3 HONO was sampled in air (—50% RH) at 20 L/min with 47-mm filters for 16-23 h. At saturation, the filters contained 1.8 xg/cm2 N02 this result indicates less than 50% efficiency for HONO retention (19). Sampling 440 xg/m3 HONO at 20 L/min with 47-mm Gelman Nylasorb filters (nylon type unstated), Sickles and Hodson reported about 25% retention efficiency, with a similar saturation value, and noted that such retention was reversible. Substantial oxidation of HONO to N03 on the filter surface by 03 was demonstrated in laboratory and atmospheric trials (21). Perrino et al. (20) observed with 47-mm Gelman Nylasorb (nylon type unstated) filters an efficiency for HONO that increased from about 25 to about 90% as the flow rate decreased from 12 to 2 L/min, with saturation at —50 xg/filter. Nitrite to nitrate conversion on the nylon filter surface increased from 13% at 45 ppb 03 to 93% at 200 ppb 03. 

This introductory case study presents the key features of a conceptual process design by using the systematic methods presented in the previous chapters. The selected process is the manufacture of cyclohexanone, a key intermediate in the production of e-caprolactam and adipic acid, which are basic materials for nylon-type polymers. 

The widely used organophosphate Insecticide methyl parathlon was the first material to be formulated as a microencapsulated pesticide. This formulation, sold under the tradename PENNCAP-M Insecticide (a registered trademark of Pennwalt Corporation), consists of nylon-type microcapsules which contain the active Ingredient. The capsules are suspended In water and typically have an average particle size of approximately 25 microns (fifty percent by weight of the capsules have a particle size of 25 microns or more). Upon application by conventional spray equipment the water evaporates, and the active Ingredient Is slowly released over an extended period of time. 

Nylons (Polyamides) There are a number of nylon types, but the most important and most widely used is nylon 6/6. The best... 

Qiana [Du Pont]. TM for a nylon-type synthetic fiber with properties similar to silk. 

Nylon type Specific gravity Melting point (°C) Tensile strength (MPa) Elongation at break (%)... 

By the addition of copolymers during spinning it is possible to modify the affinities for dyes. Three types are in production, namely regular (type 100), deep dye (type 110) and basic dye (type 120) nylons. Type 100 is normal nylon, type 110 is dyed with acid dyes but has a greater affinity and type 120 is dyed by basic dyes and is resistant to acid dyes. It is therefore possible by appropriate mixing of the yarns to obtain coloured and white, tone and tone and cross dye effects. 

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