H-Phosphonic Acid Derivatives as Catalysts for Reversible Chain Transfer Catalyzed Polymerization (RTCP) at Ambient and High Pressure

Several H-phosphonic acid derivatives (PADs) were analyzed regarding their ability to perform as effective catalysts in reversible chain transfer catalyzed polymerization (RTCP), a relatively new type of controlled radical polymerization. Therefore, bulk polymerizations of styrene at 100 degrees C using different PADs were studied in detail. The obtained number-average molar masses and polydispersities of the polymeric products showed that a cyclic PAD derived from pinacol was found to be a very well suited catalyst for RTCP under the chosen conditions. In addition, RTCPs at high pressure up to 2000 bar were conducted indicating poor molar mass control compared to the systems at ambient pressure.