Nylon 66 polyamidation relationship

The relationship between the x-ray measurements of the lattice constants of 6-6 Nylon and 6-Nylon (polyamides) as a function of temperature and the calorimetric data has already been discussed. Slichter (1958b) made an x-ray-temperature study of 6—10 polyamide and demonstrated that the 010 spacing rose with temperature, that the 100 spacing fell somewhat and that the two became equal at about 190° C. However, these lattice changes were too small to produce a noticeable effect in the specific heat measurements. If anything, the specific heat decreased from 160 to 180° C the subsequent rise was due in part, at least, to the onset of melting. 

The relationship given in Equation 4.21 is called the Carothers equation because it was first found by Carothers while working with the synthesis of polyamides (nylons). For an essentially quantitative synthesis of polyamides where p is 0.9999, the DP is approximately 10,000, the value calculated using Equation 4.21 ... 

There are relatively few data available for the synthetic polyamides. From the studies of Schaefgen and Flory (224) on 6-Nylon in sulfuric acid and those of Howard (127) on 66-Nylon in formic acid-sodium formate we derive identical values of A and of isomeric polymers is also shown in the work of Batzer and Moschle (32 f), who found that both of these Nylons and their copolymers obeyed the same viscosity-molecular weight relationship. 

It is this catalyzed reaction, involving the N=C bond, which, when carried out with diisocyanates and glycols, leads to polymers of great interest. The relationship of such polymers to the polyamides, proteins and nylons, is quickly grasped from a comparison of their structures ... 

Based on extensive research into the relationships between molecular structure and bulk physical properties, scientists at DuPont reasoned that a polyamide containing aromatic rings would be stiffer and stronger than either nylon 66 or nylon 6. In early 1960, DuPont introduced Kevlar, a polyaromatic amide (aramid) fiber synthesized from tere-phthalic acid and p-phenylenediamine ... 

The development ofand new trends in the determination of molecular weights and molecular weight distribution of aliphatic unsubstituted linear polyamides (nylons) are reviewed here. Critically discussed are intrinsic viscosity - molecular weight relationships and the conformational regidity of nylon chains. Attention is also given to some peculiarities in the behavior of nylons in multicomponent solvents. 

Polyesters provide the option of nanocomposites prepared with crystalline and amorphous continuous phases. The crystalline polymers behave in a similar way to the polyamides (nylons) as regards structure-property relationships. The amorphous polymers are a different matter. What is unexplained by first-principle arguments is the dramatic increase in percent elongation to failure [39,45,59] observed with amorphous polymer-montmorillonite composites. This phenomenon also applies to elastomers. 

Since the introduction of PEBAX by Atochem, many research groups have devoted much effort in the study of the morphology and properties of these copolymers, in addition to other PEBA systems consisting of various polyamides, such as nylon 6, nylon 11, nylon 12, etc., and polyesters, such as PTMO, poly (ethylene oxide) (PEO), and poly(propylene oxide) (PPO). This chapter aims to present an overview of these materials its scope is limited to the solid-state structure-property relationships and uniaxial deformation behavior of the PEBA copolymers. It is divided into two main sections. PTMO-PA12 systems are first presented and, in the second section, systems based on PEO or PTMO... 

---