CHARACTERIZATION OF END-GROUPS IN POLYCARBONATES BY REACTIVE PYROLYSIS-GAS CHROMATOGRAPHY

Pyrolysis-gas chromatography using the sample decomposition in the pre sence of an organic alkali, tetramethylammonium hydroxide (TMAH), was applied for end group determination of industrially available polycarb onate (PC)'s. Various phenolic compounds were observed in the conventi onal pyrograms of the PC's, which were formed through the C-C bond cle avage as well as that of carbonate linkages. On the other hand, the PC main chain almost quantitatively degraded through reactive pyrolysis at carbonate linkages to yield the dimethyl derivatives of the constit uents such as bisphenol-A through a hydrolytic pyrolysis reaction in t he presence of TMAH. In a similar manner, characteristic methyl ethers such as anisole and p-tert-butylanisole were formed from end groups. By this method, highly accurate and rapid determination became possibl e for the contents of their end groups. This information, in turn, ena bled accurate estimation of the number average molecular weight of PC' s without using any reference polymers.