Semicarbazide and thiosemicarbazide containing butylated hydroxytoluene moiety: New potential antioxidant additives for synthetic lubricating oil
Document Type
Article
Publication Date
2-24-2021
Abstract
New multipotent antioxidants (MPAOs), namely semicarbazides and thiosemicarbazides bearing thiolated butylated hydroxytoluene (BHT), were synthesized. The antioxidant activity of the synthesized compounds was evaluated using in vitro DPPH assay. Compounds containing thiosemicarbazides (5a `-h `) were found more active in free radical scavenger than semicarbazides (5a-h). Among the other compounds, compound 5f ` (IC50 of 25.47 +/- 0.42 mu M) showed the best antioxidant activity against DPPH radicals compared to standard antioxidant butylated hydroxytoluene (BHT). Based on DPPH results, compound 5f ` and its corresponding semicarbazide 5f were blended into trimethylolpropane trioleate (TMPTO) and isothermal differential scanning calorimetry (DSC) was carried out for the investigation of oxidative stability. At 125 degrees C isothermal DSC, TMPTO with 0.25 wt% of 5f ` showed 1.5 times higher oxidation stability than its corresponding semicarbazide 5f and was 2 times better than BHT. It was anticipated that due to the strong auto-synergistic effect, compound 5f ` showed promising oxidative stability to TMPTO by protecting from pre-mature oxidative degradation.
Keywords
Multipotent antioxidants, Synthesized compounds, Free radical scavenger
Divisions
fac_eng
Funders
Universiti Malaya[GC001C-14AET],Universiti Malaya[PG272-2015B],Universiti Malaya[FP127-2019A],Ministry of Education, Malaysia[GC001C-14AET],Ministry of Education, Malaysia[PG272-2015B]
Publication Title
RSC Advances
Volume
11
Issue
13
Publisher
Royal Society of Chemistry
Publisher Location
THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND