Polymers with Heterocyclic Rings in the Main Chain

Polymers with Heterocyclic Rings in the Main Chain 

In general, polymers with heterocyclic rings as structural element show a high chemical and thermal stability. On the other hand, they are insoluble and infusible, so that they could not initially be used for practical applications in this form. 

It was not until the synthesis was accomplished in two steps that it became possible to process these polymers from solution. In the first reaction step, two tetrafunctional monomers form a linear and soluble macromolecule by a polyreaction of two of the functional groups of each molecule. Subsequently, cy- 

Insoluble polymers with heterocyclic units in the main chain 

Stepwise addition polymerizations (polyaddition) or condensation polymerizations (polycondensation) are possible polyreacticais for the first step. The two latter combinations attained interest in the technical synthesis of polyimides and polybenzimidazoles. 

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