Nylon 66-type polyamide

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

Carbohydrate-based polyamides and polyurethanes constitute two major families of polymers and hence the interest in preparing aminosugars and, from them, the corresponding isocyanates. This wide research field has produced very interesting materials including the first chiral nylon-type polyamides [16]. 

Many terpolymers have been synthesized and are commercially available. This class of polyamide constitutes the basis of many of the hot melt, nylon type polyamides, which are used extensively in fobric bonding. 

Only a few solvents are known for nylon type polyamides. Among them, mineral salt-alcohol systems (particularly CaCU-methanol) are well known for their efficiency. We have found that the chiroptical properties of compound (XXII) in these solvent systems depend on salt concentration [53]. As shown in Figure 14, ORD is complex in 2M CaQ2/methanol and becomes normal while the negative CD band observed at 203-205 nm first increases in magnitude and then decreases, when the salt concentration is lowered. 

It is noteworthy that, up to now, chiroptical phenomena have been the only means to determine association constants between salt and nylon-type polyamides in highly concentrated alcoholic salt solutions. Under these conditions, UV absorption spectroscopy is unsuitable because no suitably large changes of absorption in tlie bands between 185 and 220 nm were observed. Potentiometric determination of bound and unbound Ca failed because Ca " specific electrodes dissolve in the medium. Conductometric measurements were impossible because polymer needs high salt concentrations to dissolve and only very small differences would have to be measured due to com-plexation. Nevertheless, the complexation being now identified, it seems that it will be possible to confirm the Kc values using H NMR. Indeed, CaCl2 acts as a chemical... 

It is interesting to study whether and how an engine degrades polycationic macromolecules in the presence of a polyanion. An endopeptidase, namely trypsin, that was previously shown to be capable of degrading preferentially PLL while keeping intact the PLCA and PLCAI nylon-type polyamides was selected (7). All the PEC fractions were destabilized in a 0.1 M NaH2P04 and 1.9 M NaCl solution at pH = 7.9 and at 25°C, before introduction into a 1,000 Da cut-... 

It is also by this means that we have studied the interaction of mineral salts with nylon-type polyamides in alcoholic medium using an irregular, optically active polymer (—) 1, 2-diamino propane polysebacamide (XIII). 

The synthesis of aza-2-cycloheptanone (e-caprolactam) by the Beckmann rearrangement of the oxime of cyclohexanone is of commercial importance because the lactam is an intermediate in the synthesis of a type of nylon (a polyamide called nylon-6 2) ... 

The third principal type of fibrous materials comprises the synthetic polymers. Unlike natural fibers, which apparently are always H bonded, some synthetic fibers are not H bonded. The polyamides form the best example of man-made H bonded polymers. These include nylons or polyamides, polyamino acids, polythioamides, polyurethanes, and some less well known polymers of substituted urea, hydrazide, aminotriazole, sulfonamide, or others. Specialized reference books are available (954). 

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

Since the strength of polymeric materials is attributed to intermolecular attractions, it is not surprising that polymers having functional groups that promote higher intermolecular attractions develop more strength at equivalent molecular weight than polymers in which intermolecular forces are only of weak van der Waals type. Polyamides (nylons), for example, are characterized by the structure... 

A similar, but less pronounced chain length vs chemical shift dependence is observed for a series of nylon-6,6 type polyamides based on aliphatic or aromatic a,co-diamines and aliphatic or aromatic diacids in trifluoroacetic acid. However, the downfield chemical shift caused by increasing the chain length of aliphatic diacid residues is less pronounced relative to that of aliphatic diamines [12]. 

IV. Chiral A,B-Type Polyamides (Nylons-n) Based on Amino Acids ... 

Nylon-6,6 and other AABB-type aliphatic polyamides are synthesized according to Equation 2.1, while that of aliphatic amino acids forms AB-type polyamides according to Equation 2.2. 

Thermal degradation of various aliphatic polyamides was also studied by Py-EIMS, Py-field ionization (FI), and field desorption (FD)-MS. The Py-EIMS studies demonstrated that the polylactams mainly decomposed to cyclic oligomers, whereas the favored decomposition pathways of diamine-dicarboxylic acid-type polyamides were the cis elimination reaction and the cleavage of the amide bond, which also occurred in the polylactams with a large number of methylene groups, such as nylon 12. On the other hand, Py-FIMS of various diamine-dicar-... 

Polyamide/ Nylon Type Monomers Used to Make... 

Nylon, Type 11 Nylon, Type 12 Aromatic polyamide Partially aromatic Unfilled compression and injection molding oompound 30% glass fiber-reinforced... 

---