Polycarbonate (PC)/graphene oxide (GO) composites with 3 phr of GO were prepared by using a twin screw extruder at 240, 260, and 280 ℃ after mixing the solution with chloroform. It was confirmed by DSC and TGA that the glass transition temperature (Tg) of PC/GO composites were not changed and the thermal stability was the best in case of the extrusion temperature at 260 ℃. Thermo mechanical properties of PC/GO composites according to extrusion temperatures were measured by dynamic mechanical analysis (DMA). Storage moduli of PC/GO composites were higher than that of pure PC and there was no detectable changes at varying the extrusion temperature. Based on these results, the extrusion temperature of PC/GO composites was fixed at 260 ℃. The degree of the chemical reaction of PC/GO composites with respect to the GO reduction time was confirmed by the C-H stretching peak at 3000 cm-1 and the degree of the chemical reaction was similar to that of GO when the reduction time was 1 h. A decrease in the complex viscosity as a function of the GO reduction time was detected by dynamic rheometer, which may be originated from the enhancement of GO dispersion by PC-GO reaction. The GO dispersion was confirmed by scanning electron microscope (SEM).

3 phr의 그래핀 옥사이드(GO)를 포함하는 폴리카보네이트(PC)/GO를 클로로포름에서 용액 혼합하여 응고물 침전한후 240, 260, 280 ℃의 이축압출기를 이용하여 PC/GO 복합체를 제조하였다. DSC와 TGA 측정결과 PC/GO 복합체의 유리전이 온도(Tg)의 변화는 거의 없었고, 분해거동을 통해 확인한 열안정성의 경우 260 ℃ 압출시편이 우수하게 나타 났다. 동적기계적분석(DMA)을 이용한 저장탄성률 측정결과 PC 대비 PC/GO 복합체의 값이 크게 나타났으며 압출온 도별로는 큰 차이가 없는 것을 확인하였다. 이들 결과로부터 환원시간에 따른 PC/RGO 복합체의 압출온도를 260 ℃로 고정하였다. GO의 환원시간에 따른 PC/RGO 복합체의 화학반응 정도는 3000 cm-1 부근에서 나타나는 C-H 신축진동 피크를 통해 확인하였고, 환원시간이 1 h일 때의 GO와 유사한 화학반응 정도를 나타내었다. GO의 환원시간에 따른 PC/GO 복합체의 복소점도(complex viscosity)가 감소하는 것을 확인하였으며, 이는 PC-GO 사이의 화학반응에 의한 분 산성에 기인한 것으로 주사전자현미경(SEM)을 통해 확인하였다.