1,2,4-Benzenetricarboxylic acid-1,4-anhydride butylene ester (BCAB) was synthesized from trimellitic anhydride chloride and 1,4-butanediol. The synthesized BCAB was reacted with six different diamines to produce poly(amic acid)s (PAAs), which were cyclized to yield polyimides (PIs) containing ester linkages using the thermal imidization method. Various poly(ester imide)s (PEsIs) were synthesized from structurally different aromatic diamines. The PEsI containing 2,2′-bis(trifluoromethyl) benzidine (TFB) was blended with various concentrations of poly(ethylene terephthalate) (PET) using the solution blending method. To investigate the properties of the blends, they were processed into films using a hot press. In the PEsI/PET blends, PET was not compatible with the PEsI at the tested concentrations. The addition of PET improved the optical transparency of the PEsI hybrid films, but resulted in the deterioration of their thermomechanical properties.

Trimellitic anhydride chloride와 1,4-butanediol을 이용하여 1,2,4-benzenetricarboxylic acid 1,4-anhydride butylene ester(BCAB)를 새롭게 합성하였다. 합성된 BCAB와 6가지의 서로 다른 디아민(diamine)들을 이용하여 전구체 poly(amic acid)(PAA)를 합성한 후, 열적 이미드화 반응을 통해 에스터 구조를 가지는 폴리에스터이미드(poly(ester imide), PEsI) 필름을 얻었다. 디아민 중 2,2'-bis(trifluoromethyl) benzidine(TFB)를 이용하여 합성된 PEsI와 다양한 함량의 폴리(에틸렌 테레프탈레이트)(poly(ethylene terephthalate) PET)를 용액 블렌딩 방법을 이용하여 블렌드를 제조하였다. 얻어진 PEsI 블렌드들은 열 압축 성형기를 이용하여 필름 형태로 제조하였으며 PET의 함량에 따른 물성을 조사하였다. PET/PEsI 블렌드 필름은 상용성(compatibility)이 낮았으며, PET의 함량이 증가할수록 PEsI 블렌드 필름의 광학 투명성은 증가하였지만, 열적·기계적 성질은 오히려 감소하였다.

Keywords: colorless and transparent poly(ester imide); PET; blend; thermomechanical properties; optical transparency