Synthesis of Polyimide Symmetric Monomer Containing Aliphatic Ether Diamine Chain

A series of symmetric monomer of polyimide were prepared by condensation reaction and reduction reaction from p-chloronitrobenzene and the diols.The effects of the molar ratio of the materials,the amount of potassium carbonate,reaction time,reaction pressure and catalyst on the yield were studied.The optimum reaction conditions were obtained as follows:the amount of glycol 3.1 g,the amount of potassium carbonate 15.9 g,the molar ratio of raw materials 1 ∶2.5,reaction time 24 h;the reduction reaction pressure 0.6 MPa,the amount of catalyst 0.30 g,reaction temperature 70 ℃.The total yield of 1,2-bis(p-aminophenoxy) ethane was 74.1% under these conditions.The optimum reaction conditions were also applied in the synthesis of other 3 diamines with yields in the range of49.4% ~ 65.7%.