Intermolecular increased mobility

What can be expected, if such molecules are introduced into the fiber The more mobile additive molecules have a greater chance to approach PAN — CsN dipoles in the most favorable direction (cf. Eq. 1) the intramolecular repulsion of adjacent — CsN groups within the polymer molecules will be partly neutralized , with the result of less resistance to an imposed stress. At the same time, part of the intermolecular dipole-dipole interactions between polymer molecules will be replaced by interactions of polymer CN groups with dipoles of the additive, which again results in reduced tensile strength. On the other hand, the presence of the plasticizing compound evidently provides increased mobility for the individual segments of the polymer molecules. 

Incorporation of HAp into wet PA-1 ITIO significantly modified its viscoelastic properties (Figure 13.4). It is interesting to note that in the presence of HAp, a new secondary relaxation is evident at T hap -10°C. A concomitant decrease in the high-temperature side of the tan 5 peak of the a- and j8-relaxation associated with amide sites indicates that these sites interact with themselves or with water molecules rather than directly with the ceramic surface. This results in a 15°C shift to a lower T of the primary a -loss peak as early as for 2.5 wt% HAp. The related increases mobility results from a plasticization Nanoparticles break intermolecular bonds by establishing new ones and decrease the overall interaction strength between macromolecules. The vitreous and rubbery moduli increase linearly with HAp content... 

The inhibitor contributes to increasing mobility and to the macromolecules alignment on the direction of the field of forces. In this way, intermolecular frictions are diminished, which is confirmed by the values recorded for the extrusion forces. Table 3.94. 

The formation of ECC is not only an extension of a portion of the macromolecule but also a mutual orientational ordering of these portions belonging to different molecules (intermolecular crystallization), as a result of which the structure of ECC is similar to that of a nematic liquid crystal. After the melt is supercooled below the melting temperature, the processes of mutual orientation related to the displacement of molecules virtually cannot occur because the viscosity of the system drastically increases and the chain mobility decreases. Hence, the state of one-dimensional orientational order should be already attained in the melt. During crystallization this ordering ensures the aggregation of extended portions to crystals of the ECC type fixed by intermolecular interactons on cooling. 

Scheme 8.15 compels attention to the following features of the resulting species Complexation of the cation-radical with parent neutral counterparts enhances mobility of an unpaired electron. Introduction of selenium (heavier and bulkier atom) increases the overlap among donor planes due to the better chalcogen-chalcogen intermolecular contacts. The presence of the paramagnetic nitroxyl moiety is decisive for magnetism of the product. 

In order to fit our structure model to the experimental data, we have to vary the model parameters packing density and cylinder length and examine the effects on the RDDF of our model via the structure factors S and F. One can easily see that an increase of packing density causes the intermolecular distance correlation range to increase because mobility and free volume are reduced. In other words one can calculate a realistic value of packing density (Le. cylinders per volume) from the experimental RDDF (Fig. 18). 

The forming of free volume, increases the fraction a of particles participating in the fluctuation processes between several possible conformations. Intermolecular mobility for amorphous materials begins at the glass transition temperature characterized by an increase of the free volume10. ... 

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