Fluorinated hyperbranched polyimide for optical waveguides

A novel fluorinated hyperbranched polyimide (HBPI) is synthesized by using a new triamine monomer, 1,3,5-tris(2-trifluoromethyl-4-aminophenoxy)benzene (TFAPOB) (A(3)), as a 'core' molecule, 4,4-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) as a B-2 monomer, and 3,5-ditrifuoromethylphenyl as an endcapping reagent. The polymer shows a glass transition temperature of 232 degrees C and a temperature of 10% weight loss at 535 degrees C. F, The HBPI presents a birefringence as low as 0.002 at 650 nm. Near-IR results indicate that HBPI exhibits desirable properties for low loss optical waveguide applications.