Synergetic crosslinking

The synergistic crosslinking was carried out, that is, EB-crosslinking treatment was performed after thermo-chemical crosslinking treatment of PTFE with fluorinated-pitch (1.8 wt% additive). The thermal properties of obtained crosslinked PTFE were examined by DSC analysis shown in Table II. The melting and the crystallization temperatures of radiation-crosslinked PTFE (RX-PTFE), thermo-chemical-crosslinked PTFE (CX-PTFE), synergetic-crosslinked PTFE (thermo-chemical and radiation SX-PTFE) shift to lower temperatures, compared with PTFE. 

From the solid-state 19F-MAS-NMR spectroscopy for synergetic-crosslinked PTFE (SX-PTFE EB dose 100 kGy), the new signals were observed besides the... 

Table II. The thermal properties of obtained samples PTFE, radiation-crosslinked PTFE (RX-PTFE), thermo-chemical-crosslinked PTFE (CX-PTFE), synergetic-crosslinked PTFE (thermo-chemical and radiation ...

G.V. Kozlov and V.U. Novikov, Synergetics and Fractal Analysis of Crosslinked Polymers, Klassika Publishers, Moscow, Russia, 1998. 

The idea of introducing poly(vinyl alcohol) into nylon-6,6 composition is based on the possibility of high-temperature acid-catalyzed dehydration. This reaction can be provided by the acid products of nylon 6,6 degradation hydrolysis which would promote the formation of intermolecular crosslinking and char. Such a system we have called "synergetic carbonization", because the char yield and flame suppression parameters of the polymer blend of poly (vinyl alcohol) and nylon 6,6 are significantly better than that of pure poly(vinyl alcohol) and nylon-6,6 polymers. 

At present analysis of relations between molecular characteristics, supramolecular (suprasegmental) structure parameters and properties of crosslinked polymers is carried out, as a rule, on the qualitative level [27]. It is connected with the complexity of the structure of spatial networks and the quantitative structural model for absence of these polymers [93, 130]. Therefore receiving quantitative relations between the mentioned parameters is an important goal of polymer physics, which is necessary for prediction of the properties of crosslinked polymers. The authors [130] solved this problem by the application of a number of physical concepts synergetics of deformable bodies [47], fractal analysis [92, 93] and the cluster model of the amorphous state structure of polymers [5, 6]. 

Hence, the results stated in the present section demonstrated the applicability of synergetics concepts for description of the structure of crosslinked polymers. The formation of floccules in crosslinked polymers can be considered as the formation of microgels, which at transition to the condensed state are coagulated , increasing their density by virtue of the condition d > d, typical only for crosslinked polymers. For linear polymers a swollen macromolecular coil corresponds to the condition... 

Hence, the crosslinked polymers yielding process can be described within the frameworks of synergetics of a deformable body, namely by dissipative structure evolution. The quantitative identification of DS is obtained again within the frameworks of the cluster model [47]. 

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