Hochmolekulare makrocyclische polycarbonate

✍ Scribed by Horbach, Alfred ;Vernaleken, Hugo ;Weirauch, Kurt

• Publisher: Wiley (John Wiley & Sons)
• Year: 1980
• Weight: 707 KB
• Volume: 181
• Category: Article
• ISSN: 0025-116X
• DOI: 10.1002/macp.1980.021810111

✦ Synopsis

Abstract

Interfacial condensation polymerization of bischloroformates of bisphenol A with bisphenol A results in the formation of cyclic aromatic polycarbonates of high molecular weight. Products made by this technique show a significant reduction (up to 95%) in their end group content. Also, in comparison to molecular weights determined by light scattering, these products show markedly lower molecular weights by solution viscocity measurements and by applying the Mark‐Houwink equation for linear polycarbonates. The existence of high molecular weight cyclic polycarbonates is confirmed by a controlled saponification reaction using piperidine as a basic compound. The saponification reaction causes nearly no change in the number average molecular weight of the polymer and causes an increase in the number of end groups of up to 2 end groups per molecule. The observed increase in the intrinsic viscosity data is similar to what would be expected from linear polycarbonates. It is shown that cyclic polycarbonates with molecular weights exceeding 100 000 are easily obtained.