A polyimide containing main-chain chalcone groups and hydroxyl sidegroups was synthesized.In the synthesis

1

3-dioxoisobenzofuran 5-carbonyl chloride was obtained by the reaction between 1

2

4-benzenetricarboxylic anhydride and SOCl2.1

3-Bis(4-(2-hydroxyethyl) phenyl)-prop-2-en-1-one was synthesized by the nucleophilic substitution reaction between 2-chloroethanol and 1

3bis(4-hydroxyphenyl)-prop-2-en-1one

which was synthesized from the ClaisenSchmidt condensation of 4hydroxybenzaldehyde and 1-(4-hydroxyphenyl)ethanone.The new dianhydride monomer containing chalcone group was prepared by reactions between 1

3-dioxoisobenzofuran-5-carbonyl chloride and 1

3-bis(4-(2-hydroxyethyl)-phenyl)prop-2-en-1one.The polyimide was obtained by polycondensation of the dianhydride monomer with 2

2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane and subsequent thermo imidization.The chemical structure and properties of the polyimide were characterized by  1H-NMR

FTIR

GPC and thermal analysis.The number average molecular weight (Mn) of the polyimide is 27310 with a polydispersity index of 1.55.The glass transition temperature (Tg) of the polyimide is 207℃ obtained from the DSC thermogram.The thermal degradation temperature (Td) is 382℃ measured at the point with a weight lost of 2.5% from the thermogravimetric curve.The polymer shows good solubility in aprotic polar organic solvents such as DMF

DMAc and THF.The polyimide has an absorption maximum at 342 nm due to the chalcone group.Upon the UV light irradiation

the polyimide can undergo sensitive ［2+2］ photocycloaddition reaction.After UV light irradiation with the dose of 20 J/cm2

the absorbance band at 342 nm disappears completely

and the film is insoluble in DMF.The polyimide synthesized in this work can be expected for applications as photoimagable materials and others.