Abstract
Some bismaleimide monomers, BMI(1-4), were synthesized from diamines with various structures and maleic anhydride and by the reaction of maleimidobenzoic chloride with 4,4'-(1-phenylethylidene) bisphenol, BMI-5. Chain extension of these bismaleimides was accomplished by incorporating ether or ester groups. Thermogravimetric analyses indicated that the cured bismaleimide resins are stable from 294 to 455 degrees C. Polyaspartimides P(1-8) based on BMI(1-5) were prepared by the Michael addition of diamines to bismaleimides. Some of these polymers exhibited film-forming ability. The quality of these films was studied by atomic force microscopy (AFM). Dielectric constants of the polymers films varied between 3.00 and 3.45 at a frequency of 1 kHz and from 2.96 to 3.43 at a frequency of 100 kHz. The obtained bismaleimide-based polymers had the combined advantages of low dielectric constant and dielectric loss, good-temperature resistance and good processability. These new polymers will contribute to extend the field of their applications as high performance polymers.