| abstract |
The present invention provides a catalyst for use in the preparation of a coloured polymeric material, said catalyst comprising a coloured organometallic compound. Preferably, said catalyst comprises a metal such as aluminium and at least one organic chromophore, such as an azo chromophore, said chromophore being either directly bonded to said metal, or indirectly bonded to said metal through a ligand. The invention also envisages a method for the preparation of a coloured polymer, the method comprising performing a polymerisation reaction in the presence of such a catalyst. The method is particularly applicable to the preparation of poly(lactic acid), and offers significant benefits over the processes of the prior art, both economically and environmentally. |