Partially crystalline state parameters

Linear aliphatic homopolyamides are partially crystalline materials. Therefore they are characterized by both an unordered amorphous state and an ordered crystalline state. The latter may exhibit polymorphism. The extent to which each state or specific modification is represented depends, for a given chemical structure, considerably on processing conditions and treatment operations. It affects the properties of the shaped polyamide product. Thus the corresponding structure parameters are of importance for optimizing fiber processes as well as for assessing the performance of fiber products in particular applications. 

The Mossbauer spectrum of ferrous Y-zeolite is somewhat similar to that of the reduced silica gel samples (103). The spectrum consists of two overlapping and partially resolved doublets with the inner doublet, 3 = 0.89 mm sec-1 and A = 0.62 mm sec-1, being attributed to the ferrous ion on the surface. In both the Y-zeolite and the reduced iron oxide on silica samples, the inner doublets representing surface ferrous states are the first to be affected by adsorption of polar molecules, but in the case of Y-zeolite the addition of excess amounts of water or ammonia causes the disappearance of the spectrum, and this has been interpreted in terms of "solvation of the ferrous ions by absorbate causing weakening of the bonding to the crystalline lattice. It is also possible that the spectrum is a composite representing a multiplicity of parameters. 

The parameter % in the Eq. (4.9) characterizes a polymer fraction, which does not participated in plastic deformation process, but subjects to elastic deformation. For semicrystalline pol5mier this fiaction consists of devitrificated amorphous phase and crystalline phase part, which was subjected to partial mechanical disordering [4]. In other words, the parameter % characterizes he deformed polymer structural state. For the considered in Refs. [2, 3] HDPE crystallinity degree K= 0.687 and, hence, amorphous phase fraction (p, makes up 1 - = 0.313. As estimations according to the Eq. (4.9),... 

To the contrary, study of the second moment and various relaxation times of the resonance line as a function of temperature and other parameters often yidLds important data on the polymer such as degree of crystallinity, chain axis orientation, and degree of molecular motion. Indeed, so-called wide-line NMR has been one of the primary methods of characterizing the bulk state of polymeric systems. Nonetheless, it might be assumed that if a high-resolution NMR spectrum of a solid could be obtained, new detail on the nature of the solid state might be uncovered. Recent advances in magnetic resonance have now made possible the partial realization of this... 

---