Nylons commercially available

Nylon-6,6 [32131 -17-2] and nylon-6 [25038-54-4] continue to be the most popular types, accounting for approximately 90% of nylon use. There are a number of different nylons commercially available Table 1 gives a summary of the properties of the more common types. In the 1990s there has been a spurt of new polyamide iatroductions designed for higher temperatures, better stiffness and strength, and/or lower moisture uptake. 

Adhesion. Commercially available 1- or 2-coat adhesive systems produce mbber failure in bonds between ethylene—acryflc elastomer and metal (14). Adhesion to nylon, polyester, or aramid fiber cord or fabric is greatest when the cord or fabric have been treated with carboxylated nitrile mbber latex. 

Commercial engineering thermoplastic nylons are mainly crystalline resins. Nylon-6,6 [32131 -17-2] is the largest volume resin, followed by nylon-6 (48). Other commercially available but much lower volume crystalline nylons are -6,9, -6,10, -6,12, -11, and -12. The crystallinity of the molded part decreases with chain size (49). A few truly amorphous commercial nylon resins contain both aromatic and ahphatic monomer constituents (50). For example, Trogamid T resin is made from a mixture of 2,2,4- and 2,4,4-trimethylhexamethylenediamines and terephthahc acid (51). 

Freeing a solution from extremely small particles [e.g. for optical rotatory dispersion (ORD) or circular dichroism (CD) measurements] requires filters with very small pore size. Commercially available (Millipore, Gelman, Nucleopore) filters other than cellulose or glass include nylon, Teflon, and polyvinyl chloride, and the pore diameter may be as small as 0.01 micron (see Table 6). Special containers are used to hold the filters, through which the solution is pressed by applying pressure, e.g. from a syringe. Some of these filters can be used to clear strong sulfuric acid solutions. 

Methylmethoxy nylons are commercially available in which about 33% of the —NH— groups have been substituted. 

Fibers in which the basic chemical units have been formed by chemical synthesis, followed by fiber formation, are called synthetic fibers. Examples include nylon, carbon, boron fibers, organic fibers, ceramic fibers, and metallic fibers. Among all commercially available fibers, Kevlar fibers exhibit high strength and modulus. (Kevlar is a DuPont trademark for poly [p-phenylene diamine terephthalamide].) It is an aromatic polyamide (aramid) in which at least 85% of the... 

Various on-line SFE-SFC applications for the analysis of polymer additives and oligomers have been reported, such as additives in PE [121] polymer additives and oligomers in PP nylon pellets and PEEK granules [15] and oligomers in PET films [103], PS [122] and PMMA [123], sometimes in quantitative fashion [15,103]. SFE-SFC has identified the cyclic trimer tris-(ethylene terephthalate) in commercially available PET film [103]. Also, SFE-SFC extraction and... 

Preparation of Linear and Star Nylon 6. The star-branched initiator, trimesoyl-tris-caprolactam (TTC) 6 was synthesized from the commercially available trimesoyl chloride 5 using the route shown in Figure 2. (6) Trimesoyl acid chloride in benzene was slowly added to a stirring solution of e-caprolactam, pyridene, and benzene. After addition was complete, the solution was heated to 70° C for 30 minutes to assure conversion to the initiator species. Single and difunctional analogs were synthesized using the same reaction scheme for direct comparison of the star-branched and linear aromatic initiator systems. 

The initiation period in the lactam-opening polymerization may be shortened by addition of an activator, such as acetyl chloride. Nylon-4, nylon-8, and nylon-12 are commercially available and used as fibers and coatings. 

Trons-l,2-diaminocyclohexane, the most popular representative of the primary diamines and its derivatives, has been widely utilized in the field of stereoselective organometallic catalysis as chiral reagents, scaffolds, and ligands [137]. This C2 symmetrical chiral diamine first reported in 1926 by Wieland and co-workers [193] is commercially available, since it is a component in a byproduct amine stream generated during the purification of 1,6-hexanediamine that is used in the industrial Nylon 66 production. The racemic mixture of this diamine can be easily... 

Several commercially available monadic nylons have the following re panting unit ... 

In addition to the basic nylons, a variety of copolymers can be manufactured, some of which are commercially available. Nylons and nylon copolymers can be blended to form alloys with specific customized proper ties. 

Hexamethylenediamine (HMDA) is a colorless solid when pure, but it slowly degrades to colored products when it contacts air. It is commercially available as the anhydrous product or in aqueous solutions. In 2003 it had a global capacity that was approaching 3.0 billion pounds per year, and it was made by only one main route hydrogenation of ADN. Commercially the most important use of HMDA is in a polycondensation reaction with adipic acid to eventually give nylon 6,6274. The chemical formula for HMDA is ... 

Epoxy-phenolic adhesive compositions of commercially available types Epoxy-nylon adhesive composition... 

RNAs are denatured by formaldehyde/heat treatment. All of the stock solutions for RNA slot blots are made using sterile diethyl pyrocarbonate (DEPC)-treated water. RNAs are diluted as necessary from stock solutions with water, and 3 volumes of 6.15 Mformaldehyde in 10X standard saline citrate (SSC) is added to give a final RNA concentration of 10-100pg/ml. The RNA dilutions are heated to 65° for 15 min and quick-chilled on ice. The denatured stock is further diluted with 4.16 M formaldehyde in 7.5 X SSC such that the desired concentration of RNA may be applied to each slot in a total volume of 400 pi. The nylon membrane is piewet in water and then soaked in 10X SSC for 20 min. Slot blots are performed using a commercially available apparatus hooked to a vacuum source. After the samples are blotted through, each well is washed with 400 pi of 10 X SSC. The membrane is removed from the apparatus and baked in a vacuum oven at 80° for 2 hr. 

Commercially available static mixer reactors (SMR) as large as 1.8 m in diameter are operating in the production of nylon, silicones, polystyrene, polypropylene, and other polymers. Removing heat from a highly exothermic reaction in a static mixer equipped with a simple cooling jacket is limited by heat transfer to small diameters, typically less than 6 in. A new type of static mixer has been developed to overcome laminar heat-flow transfer problems. It is called the SMR mixer-heater exchanger-reactor (Mutsakis et al, 1986). 

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