In order to develop a material having balanced properties of the toughness of thermoplastic and the heat resistance of thermoset, semi-IPN's composed of bisphenol A dicyanate (BPACY) and polyarylate (PAR)was synthesized and its properties were studied. The semi-PN was synthesized by Polymerizing the mixture of BPACY monomer and polyarylate obtained by solution blending the two components and removing the solvent. Semi-IPN synthesized were transparent in all the composition, but scanning electron microscope (SEM) results of the semi-IPN's showed the phase separated morphology. Sea and island morphology of continuous polydicyanate and dispersed polyarylate above 85wt% of BPACY, while interconnected nodular morphology was observed when the composition was below 80wt% of BPACY. For the semi-IPN of BPACY 80wt%, sea and island morphology and interconnected nodular morphology co-existed and this implied that the phase inversion occurred at this composition. In the dynamic mechanical analysis(DMA), two T_gs were observed in IPN's having 50wt% or more poly(dicyanate), and single T_g was observed when the composition was below 50wt% of poly(dicyanate). It was observed that tensile strength elongation at break, flexural strength, and flexural modulus increased with increasing polydicyanate contents, while impact strength decreased with increasing polydicyanate content.

Semi-IPN의 개념을 이용하여 열경화성 수지의 내열성 및 내화학성과 열가소성 수지의 강인성을 조합한 재료를 제조하고 미세구조와 몰폴로지, 그리고 물성과의 연관 관계를 규명 하고자 하였다. 열경화성 성분으로 Bisphenol A dicyanate(BPACY) 수지를 사용하고 열가소성 성분으로 polyarylate(PAR)를 사용하여 용액 블렌딩 기법으로 semi-IPN을 제조하였다. 제조된 semi-IPN은 전 조성에서 투명하였.으나 전자현미경 관찰 결과와 동적 점탄성 측정 결과 상분리된 몰폴로지를 확인하였다. 본 시스템의 경우 최종 생성물의 몰폴로지는 BPACY 모노머의 반응 속도와 상분리 속도간의 상대적 우위에 의하여 결정된다. 본 연구에서는 조성, 반응 온도, 촉매의 함량 등을 변화시켜 최종 생성물의 몰폴로지를 조절하고 이것이 Izod 충격강도나 굴곡강도등의 기계적 물성에 미치는 영향을 살펴 보았다. 또한 Vicat 연화온도를 측정하여 제조된 semi-IPN의 내열특성을 고찰하였다.

Keywords: semi-IPN; dicyanate; polyarylate