title preparation and performance of colorlesstransparent polyimide film abstract dianhydride 9fda and diamine 22'-bis-trifluoromethyl -44'-diamino-diphenylether(tfoda) were adopted to prepare a colorless transparent fluorinated polyimide (pi) film by two-step in nn'-dimethylacetamide (dmac).after the analysis of tensile strength tg and ultraviolet-visible spectrum it is found that tensile strength of the resultant film reaches 85.0mpat5% is larger than 530°c t10% is over 550°c cut-off wavelength is 330nm and transmission is up to 96.0% which showed excellent comprehensive performance. we also investigated the influence of different content of 33’44’-odpa (n(9fda):n(odpa)= 9:18:27:3 6:45:5 and 4:6 respectively ) on the mechanical property thermal property and optical property compared with 9fda- tfoda- pi. results showed that the mechanical property and thermal property of pi films can be improved by adding odpa but the optical property and adhesion performance reduced. the incorporation of trifluoromethyl group into pi molecular chain can also decrease the adhesion performance of pi film with other materials significantly. by introducing silicon-containing diamine α-ω-diaminopropyl polysiloxanes (pmds) into the molecular chain we explored the effect of different silicon-containing diamine content (n(tfoda):n(pmds)=95:590:1085:1580:20) on its various properties of pi film especially on adhesion performance. it was found that when n(tfoda):n(pmds)=90:10 adhesive force on glass plate of pi can achieve grade 2 boiling time is over 24 hours tensile strength is 79.1mpat5%=498℃ t10%=542℃ cut-off wavelength is 338nm and transmission is up to 93.7% which presents excellent comprehensive performance.
keywords polyimide film; colorless and transparent; adhesive force.