그래핀을 코팅한 폴리우레탄 폼의 전기적 특성과 연소성

Abstract

연질 폴리우레탄(flexible polyurethane, FPU) 폼에 열환원법으로 제조한 그래핀(thermally reduced graphene, TRG)를 poly(vinyl chloride) (PVC)를 고착제로 사용하여 코팅하고, 전기적 성질, 그리고 난연성의 변화를 조사하였다. 코팅된 TRG의 양이 증가함에 따라 표면 저항이 감소하여, FPU 폼 100 부 대비 약 2 부(2 phr)의 TRG가 코팅된 경우 10^4 Ω square-1에 이르러 일정한 값을 유지하였다. 전자파 차폐 효율 역시 코팅된 TRG의 양에 따라 증가하여, 코팅된 TRG 양이 15~20 phr 부근인 경우, 3~4 dB 근처의 차폐능을 발현하였다. 그리고 코팅된 TRG 양이 10 phr 부근인 경우 자소성이 관찰되었다.|Thermally reduced graphene (TRG) was coated on flexible polyurethane (FPU) foam using poly(vinyl chloride) as a binder, and its electrical properties and flame retardancy were investigated. As the amount of coated TRG increased, the surface resistivity decreased. When TRG/PVC ratio was fixed at 75/25, surface resistivity reached a constant value of 10^4 Ω square-1 when about 2 parts of TRG (2 phr) was coated on 100 parts of FPU foam. The electromagnetic shielding efficiency also increased with the amount of coated TRG, and when the amount of coated TRG was in the vicinity of 15 to 20 phr, it exhibited shielding efficiency around 3 to 4 dB. The coated TRG reduced the flammability of FPU foam. Self-extinguishing was observed when the amount of coated TRG was about 10 phr, and the amount of TRG needed for self-extinguishing was reduced when the amount of PVC used as binder increased.