No abstract

No abstract

The phase appearance during the synthesis of fluorinated polyamic acid (PAA) from 2,2-bis(3,4-anhydrodicarboxyphenyl)-hexafluoropropane (6FDA) and 2,2 0 -bis(trifluoromethyl)24,4 0 -diaminobiphenyl (TFDB) in supercritical carbon dioxide (scCO 2 ) was investigated to obtain fundamental data for the deposition of fluorinate polyimides (PI) using scCO 2 . All polymerizations were carried out at 30 MPa for 60 min. The experimental temperatures ranged from 50 to 70 8C, and each of the monomer concentrations ranged from 0.67 3 10 25 to 3.3 3 10 25 mol cm 23. The holding time of the transparent phases, which was the time from the beginning of the polymerization to the appearance of a turbid phase, was increased with either a decrease in the polymerization temperature or a decrease in the initial monomer concentration. The holding time of the fluorinated PAA was longer than that of the monomers of Kapton-type PAA. The deposition of PI into the microscopic-scale trenches that had formed on the silicon wafer was successful in scCO 2 .

No abstract