A Solvent Free Catalyst for Polycarbonate Production

Ref: 12053
The preparation of crystalline Zinc Glutarate (ZnGa) in an organic solvent free synthesis. ZnGa is widely used as a catalyst in the manufacture of poly-carbonates.

Key advantages
  • Toluene free synthesis of catalyst
  • Utilisation of existing polycarbonate production infrastructure
  • Low cost of manufacture, increased catalytic turnover and yield

Background

ZnGa is widely used in the catalytic copolymerization reaction of CO2 and epoxides to form polyalkylene-carbonate plastics. The catalyst ZnGa is produced by the reaction of Zinc Oxide and Glutaric acid in boiling toluene or boiling benzene. The resultant ZnGa is an amorphous material, and although highly effective as a catalyst, ZnGa is becoming undesirable due to the carcinogenic nature of its precursors. There are a limited number of alternative Zn based catalysts, however these have not found wide-spread industrial applicability due to poor yield, lower catalytic activity or equally toxic precursors. Industry is looking for ways to reduce the use of carcinogenic and flammable solvents such as toluene and benzene.

The invention

Top: The amorphous nature of ZnGa produced by toluene synthesis

The amorphous nature of ZnGa produced by toluene synthesis

The preparation of crystalline ZnGa has been achieved by the application of proprietary technology. Most importantly this technology does not use any organic solvents. The catalyst can be produced in yields > 90%. The crystallinty of the resultant catalyst can be optimized. The catalytic efficiency of the resultant product is greater than that of toluene produced ZnGa. The use of this material as a catalyst would not require any changes to the infrastructure currently used to carry out the poly-carbonate co-polymerisation reaction.

Applications

The micro-crystalline nature of USYD - ZnGa

The micro-crystalline nature of USYD - ZnGa

The preparation of crystalline ZnGa has been achieved by the application of proprietary technology which does not use any organic solvents. The catalyst can be produced in yields > 90%, and the crystallinty of the resultant catalyst can be optimized. The catalytic efficiency of the resultant product is greater than that of toluene produced ZnGa, and the use of this material as a catalyst would not require any changes to the infrastructure currently used to carry out the poly-carbonate co-polymerisation reaction.

Principal inventors

  • Associate Professor Fariba Dehghani
  • Rachel Zhong

Download technology summary (PDF)