Reaction of 3′-trifluoromethyl-2

2

2-trifluroacetophenone (1) with toluene in the presence of concentrated sulfuric acid and 3-mercaptopropionic acid at reaction temperature of 40 ～ 50℃ for 8 h afforded 1

1-bis (4-tolyl) -1- (3′-trifluoromethylphenyl) -2

2

2-trifluoroethane (2)

which was further oxidized to 1

1-bis (4-carboxyphenyl) -1- (3′-trifluoromethylphenyl) -2

2

2-trifluoroethane (3) using oxygen catalyzed by N-bromosuccinimde (NBS) under photoirradiation in 77.4% overall yield.Then the nucleophilic substitution solution polycondensation of diacid 3 with 9

9-bis[4- (4-aminophenoxy) phenyl]xanthene using Yamazaki method yielded a new polyamide containing trifluoromethyl and xanthene groups with high molecular weight (the number-average molecular weight is 43000

the polydispersity index is 1.8) .The polymer was amorphous and exhibited high transparency with an ultraviolet-visible absorption cut-off wavelength at 330 nm.This polyamide showed a glass transition temperature (Tg) of 242℃

decomposition temperature (Td) at 5% weight loss of 465℃ and char yield of 50% at 800℃ in N2.This new polyamide was readily soluble in organic solvents such as N

N-dimethylacetamide (DMAc)

N

N-methyl-2-pyrrolidone (NMP)

m-cresol

pyridine and tetrahydrofuran.Transparent

flexible

and tough films of the polymer cast from DMAc solution exhibited tensile strength of 85 MPa

elongation at break of 10% and tensile modulus of 2.0 GPa.The electrical properties of this polymer such as the volume resistivity of 2.85 × 1015 Ωcm

surface resistivity of 4.23 × 1014 Ω and dielectric constant of 3.55 (100 Hz) indicated its excelllent electrical resistance property.