High-elasticity, theory

The limiting draw ratio attained by stretching a polymer is determined, in terms of the rubbery high-elasticity theory, by the equality [124] ... 

The above equations follow from the classical high elasticity theory and the Flory theory of polymeric networks. ... 

Within the framework of high-elasticity theory the value G in the equation (13) is determined as follows [18] ... 

The value knowledge allows formally to calculate the density of macromolecular entanglements network in polymeric medium according to the well-known expressions of high-elasticity theory [23] ... 

As it is known [83], a glassy polymers behavior on cold flow plateau (part III in Fig. 4.17) is well described within the frameworks of the rubber high-elasticity theory. In Ref [39] it has been shown that this is due to mechanical devitrification of an amorphous polymers loosely packed matrix. Besides, it has been shown [82, 84] that behavior of polymers in rubber-like state is described correctly under assumption, that their structure is a regular fractal, for which the identity is valid ... 

Thus the results obtained within the frameworks of the rubber high-elasticity theory suggest that the macromolecular entanglement network in semi-crystalline polymers is... 

The main distinction between physical entanglements ( sweeps ) nodes and chemical crosslinking nodes is chains sliding in the former. The density of both can be determined according to the high-elasticity theory and for calculation of chains sliding in entanglements nodes the coefficient 0.8 is added [49]. 

Let us demonstrate the examples of dimension D usage for the applied problems settlement. The limiting draw ratio of polymer tension within the framework of high-elasticity theory is determined according to the formula [59] ... 

As a rule, at present crosslinked polymer networks are characterised within the frameworks of entropic rubber high-elasticity concepts [2, 3]. However, in recent years works indicating a more complex structure of crosslinked rubbers have appeared. Flory [4] demonstrated the existence of dynamic local order in rubbers. Balankin [5] showed principal inaccuracy of the entropic high-elasticity theory and proposed a high-elasticity fractal theory of polymers. These observations suppose that more complete characterisation of these materials is necessary for the correct description of the structure of rubbers and their behaviour at deformation. In paper [6] this was carried out by the combined use of a number of theoretical physical concepts, namely the rubber high-elasticity entropic theory, the cluster model of the amorphous state structure of polymers [7, 8] and fractal analysis [9]. 

The density of the chemical crosslinking nodes network was determined according to the rubber high-elasticity theory [10] ... 

Therefore in papers [46-48] the fractal treatment of high-elasticity theory was proposed, which does not possess the indicated deficiencies. In paper [49] description... 

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