Highly reactive polyisobutylene (HRPB) derivatives were synthesized by introducing thiadiazole group containing S and N elements into highly reactive polyisobutylene (HRPB). In order to study the friction reduction effect of these derivatives, the WSD (wear scar diameter) of 1 wt% solution of HRPB derivatives in Yubase 6 (SK) was observed by the ASTM D4172 method using a 4-ball tester. The friction reduction effect of the new HRPB derivatives was similar to or higher than that of the commercial products such as Zn-DTP. The surface analysis of the wear scar was investigated by using SEM-EDX and XPS. We observed that the sulfur content on the wear scar surface was dramatically increased compared to pure surface, not rubbed. From the binding energy of S2p, it was supposed that sulfur made a complex with iron and existed as FeS₂ on the wear scar. We concluded that the friction reduction effect of the new HRPB derivatives containing thiadiazole group is attributed to a strong interaction between sulfur and iron on the metal surface

고반응성 폴리부텐(HRPB)에 싸이아다이아졸 그룹을 도입하여 새로운 유도체를 합성하였다. 이들의 마찰 저감 효과를 확인하기 위하여 Yubase 6(SK)를 기유로 사용하고 1 wt% 농도로 첨가하여 4-ball 마모흔의 직경을 비교하였다. 새로운 HRPB 유도체에 의한 마찰 저감 효과는 Zn-DTP와 같은 상업제품들과 비교하였을 때 유사 혹은 월등한 결과를 보여주었다. 우수한 마찰 저감 효과에 대한 이해를 위해 SEM-EDX와 XPS를 사용하여 마모흔의 표면을 분석하였다. 마찰흔 표면에서 황(S)의 함량이 현저히 증가하는 것을 확인하였고 황은 철과 결합한 FeS₂ 상태로 존재함을 알 수 있었다. 이로부터 싸이아다이아졸을 포함하는 새로운 HRPB 유도체에 의한 마찰 저감 효과는 분자 내 존재하는 황이 쇠구슬 표면과 강한 상호 작용으로부터 기인한다는 것으로 판단된다

Keywords: highly reactive polyisobutylene derivatives, 1,3,4-thiadiazole, lubricant additives, anti-wear, surface analysis