A poly(amic acid) (PAA) was prepared by the reaction of bicyclo(2,2,2)oct-7-ene-2,3,5,6-tetracarboxylicdianhydride (BCD), containing double bonds for crosslinking, and bis[4-(3-aminophenoxy)phenyl] sulfone (BAPS) in N,N-dimethylacetamide (DMAc). The PAAs were heat-treated with two different catalysts, α,α'-azobisisobutyronitrile (AIBN) and Grubb's catalyst, as crosslinking agents to create crosslinked, colorless, and transparent polyimide (CPI) films. The thermal properties, degree of crosslinking, and optical transparency of the CPI were investigated by increasing the catalyst content from 0 to 0.10 wt%. We also tried to clarify the catalytic effects of the two catalysts (AIBN and Grubb's) on CPI films. The CPI film with the catalyst had better thermal property than pure CPI; in contrast, the addition of the catalyst to the CPI film was found to deteriorate the optical property. The thermal property and optical transparency of the CPI films with two different catalysts were found to be almost similar.

가교 반응이 가능한 2중 결합을 갖는 bicyclo(2,2,2)oct-7-ene-2,3,5,6-tetracarboxylic-dianhydride(BCD)와 bis[4-(3-aminophenoxy)phenyl] sulfone(BAPS)을 N,N-dimethylacetamide(DMAc)에서 반응하여 폴리아믹산(poly(amicacid), PAA)을 얻었다. PAA에 두 가지 촉매를 각각 0~0.10 wt%씩 첨가하고 열처리하여 가교된 무색 투명한 폴리이미드(colorless and transpatrent polyimide, CPI)를 합성하였다. 촉매의 양에 따라 가교된 폴리이미드의 열적 성질, 가교도, 광학적 특성을 조사하였으며, α,α'-azobisisobutyronitrile(AIBN)과 Grubb's의 두 가지 촉매의 종류에 따른 물성을 서로 비교하였다. 두 가지 촉매가 첨가된 CPI의 물성은 촉매 없는 순수한 CPI보다 열적 성질은 더 증가하였으나 광학적 성질은 오히려 감소하였으며, 두 가지 촉매를 사용하여 얻은 CPI의 열적 성질과 광학적 투명성은 서로 큰 차이가 없었다.

Keywords: colorless and transparent polyimide; crosslinkable monomer; α,α'-azobisisobutyronitrile; Grubb's catalyst; films