Photosensitive polyimide (PSPI) precursors, which were comprised of benzophenone tetracarboxylic dianhydride (BTDA) and four different diamines, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane(BIS-AP-AF), 2,2-bis(3-amino-4-methyl phenyl)hexafluoropropane (BIS-AT-AF), 2,4-toluene diamine (2,4-TDA), and 2,2-bis[(4-amino-phenoxy)phenyl] propane(BAPP), have been synthesized. The viscosity of the four PSPI precursors varied from 0.32 to 0.40 ㎠/g, and the number average and the weight average molecular weights measured were between 3300 and 4300 g/mol and between 9800 and 12300 g/mol, respectively. The precursors were soluble in aprotic solvents, DMAc, DMF, NMP, and chloroform, but insoluble in other solvents. The degree of photoreactivity of the prepared PSPI increased with the UV-exposure time, but it was relatively lower than that of the commercial product. The broad glass transition temperatures imply that the polyimide precursors were partially crosslinked, and this result is consistent with the observed photoreactivity. The molecular weights, the viscosity, and the thermal stability of the synthesized PSPI precursors were similar to those of the conventional product, but the formation of a flexible film was difficult due to insufficient information on molecular weight of the precursors. Thus it is required to develope a method for improving the photoreactivity in a short duration of time.

BTDA(benzophenonetetracarboxylic dianhydride)와 4가지의 diamine인 2,2-bis(3-amino-4-hydroxypheny)hexafluoropropane(BIS-AP-AF), 2,2-bis(3-amino-4-methyl phenyl)hexafluoropropane(BIS-AT-AF), 2,4-toluene diamine(2,4-TDA), 2,2-bis[4-(4-aminophenoxy)phenyl] propane (BAPP)를 이용하여 감광성 폴리이미드(photo-sensitive polyimide: PSPI) 전구체를 합성하였다. 네가지 폴리이미드 전구체의 점도는 0.32∼0.40 ㎠/g 이었으며, 수평균 분자량과 중량 평균 분자량은 각각 3300∼4300과 9800∼12300 g/mol로 측정되었다. 용해도는 비양자성 용매인 DMAc, DMF, NMP 및 chloroform에는 잘 용해되었고, 그 밖의 양자성 용매에는 불용성을 보였다. 광반응성 측정에서 노광시간이 증가할수록 광반응도는 증가하였지만, 상용 폴리이미드에 비해서 낮게 나타났다. 넓은 범위에서 나타나는 유리전이 온도로부터 이들 시료가 부분적으로 가교되었음을 증명해 주었고, 이는 낮은 광반응도와 일관성있는 결과로 해석된다. 합성한 PSPI 전구체의 점도, 분자량 및 열 안정성은 상용화된 제품과 비슷한 결과를 보인 반면, 유연한 필름 생성이 어려웠는데,이는 합성된 PSPI 전구체의 가교도가 낮아 일어난 현상으로 짧은 시간에 광반응도를 높일 수 있는 방법이 요구된다.