Bisdichloromaleimide preparation

Six bisdichloromaleimides having different aromatic structures were prepared by reacting 2,3-dichloromaleic anhydride with (a) 1,5-diaminonath-thalene, (b) bis(m-aminophenyl)methylphosphine oxide,... 

Relies and Schluenz (8) have reported the preparation of poly(maleimide-ethers) by using bisphenols and bisdichloromaleimides. These polymers were soluble in dimethylformamide (DMF) and dimethylsulfoxide (DMSO) and gave tough flexible films. Phosphorus-containing poly(maleimide-amines) have been reported to have poor thermal stability and little flame retardation (9). 

Preparation of Bisdichloromaleimides. The method of Martin et al. (14) was used for the preparation of bisdichloromaleimides. Diamines (0.005 mole) and 2,3-dichloromaleic anhydride (0.01 mole) were separately dissolved in glacial acetic acid and the solutions were then mixed and heated slowly to reflux temperature. After refluxing for 2 h, the solutions were cooled, and bisdichloromaleimides were precipitated in water. The products were filtered and washed with water until free of acetic acid. After drying, the products were recrystallized from toluene/hexane. 

Preparation of Polymers. The polymerization of the above prepared bisdichloromaleimides was carried out according to the method of Relies and Schluenz (8). The 9,9-bis(p-aminophenyl) fluorene (0.001 mole) was dissolved in 10 ml of freshly distilled DMF containing 0.002 mole of triethylamine as an acid acceptor. 

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