Preparation And Characterization Of Self Sensitization Photosensitive Polyimide

In this paper,polyimide precursor solution based on 3,3',4,4'-benzophenone tetracarboxylic dianhydride,3,5-diaminobenzoic acid,p-aminobenzoic acid and N,N'-dimethyl acetamide as a solvent,p-aminobenzoic acid as a capping agent was synthesized through solution polymerization.The solution of photosensitive precursor with photosensitive group in side chains were synthesized by adding 4-hydroxy chalcone and cinnamic alcohol as a photosentive function monomer,respectively.Two kinds of photosensitive polyimide solution were obtained by chemical imidization.Then two kinds of photosensitive polyimide resins were obtained by precipitation and washing with de ionized water and drying.The structures of two kinds of photosensitive polyimide resins were characterized by fourier transform infrared(FTIR)analysis and nuclear magnetic resonance spectroscopy(~1H-NMR).The results showed that two kinds of photosensitive polyimide resins were synthesized successfully.The structure of the polyimide film before and after exposure was compared with FTIR analysis,it was found that the characteristic absorption peak corresponding to C=C disappeared.The resulting indicates that the crosslinking reaction of C=C in the structure of the photosensitive polyimide containing chalcone group occurred after UV exposure.Gel permeation chromatography(GPC)analysis showed that the molecular weight of photosensitive polyimide resin containing chalcone and cinnamyl group was 5047 and 4628,respectively.Ultraviolet visible absorption spectrum analysis(UV-Vis)showed the maximum UV visible absorption wavelength of photosensitive polyimide resin containing chalcone and cinnamyl group was 319 nm and 326 nm,respectively.The results of dissolution analysis showed that the two kinds of photosensitive polyimide had good solubility,and the dissolution of the photosensitive polyimide film was decreased.In addition,the photosensitive properties of two kinds of photosensitive polyimide resins were tested and analyzed.The results showed that the appropriate exposure time of photosensitive polyimide film with chalcone group was shorter than that of the photosensitive polyimide film with cinnamyl group,and the exposure time is 90s and 100s,respectively.The thermal gravimetric analysis(TGA)revealed that the temperature of 5%weight loss for UV-cured polymer of photosensitive polyimide film with chalcone and cinnamyl group was 351? and 280?,respectively.