ISSN:
1573-9171
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Conclusions 1. The processes that occur in polyheteroarylenes at temperatures preceding the beginning of weight losses were studied. 2. When polyheteroarylenes are heated under vacuum to 200°C there is an increase in the molecular weight, associated with the process of condensation of the terminal groups. Above 200°C, structuration predominates, manifested initially in the formation of branched, and then of crosslinked structures. 3. The principles of the formation of crosslinked structures were established for the example of poly-1,3,4-oxadiazole based on phthalidedicarboxylic acid (polymer I), and the nature of the accumulation of crosslinks was followed. It was shown that there is a limit of the content of the gel fraction. 4. The values of the thermodynamic parameter of the polymer-solvent interaction of the fractions of polymer (I) with tetrachloroethane were measured. The dependence of the intrinsic viscosity of the polymer (I) on its molecular weight was found.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00907594
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