Investigation on physical, thermal and chemical properties of palm kernel oil polyol bio-based binder as a replacement for bituminous binder

•Ea values showed that the BIBs have higher resistance to flow than BB.•The thermal susceptibility of BIB blends is very similar to that of the BB.•FTIR indicated that the BIBs was distinct from BB in terms of functional group.•The aged BIB blends exhibited new carbonyl group as compared to BB. The high demand for bituminous binder has affected the price and quality of binders, and this has prompted research to be conducted to discover new binders from renewable resources. Thus, this study aims to characterize engineering properties namely the physical, thermal and chemical bonds of palm kernel oil polyol (PKO-p) bio-binder by means of consistency, rational viscosity (RV), differential scanning calorimetric (DSC), thermo-gravimetric analysis (TGA) and Fourier transform infrared spectrometer (FTIR) tests. A new bio-binder containing PKO-p was used as a partial replacement for petroleum-based binder. The PKO-p was produced through esterification then condensation processes. The proposed PKO-p was blended with a 80/100 penetration grade bitumen (BB) to produce the three different bio-binder (BIB), namely 100/0, 80/20, 60/40, and 40/60 bio-binder (weight of BB to BIB). Result showed that the values of the rotational viscosity (RV) of the BIBs were very consistent with that of the control binder, and that the compaction and mixing temperatures of the BIBs were reduced by 10% comparing with those for the control binder. Conventional testing of softening point and mixing temperature yielded similar results. The activation energy (Ea) for the three bio-binders were 85.47, 90.19 and 86.62 kJ/mol while that for BB was 71.44 kJ/mol. The thermal susceptibility of the BIBs blends were very similar with that of the BB and a small difference in weight losses was observed, i.e. with values from 0, 0.12%, 1.40% and 3.36% for BB, BIB1, BIB2 and BIB3 respectively. FTIR results showed that bio-binder was distinctly different from petroleum bitumen with regard to functional group, but very similar in other aspects. The findings of this study showed that the new PKO-p bio-binder has promising properties that made it a suitable alternative for petroleum-based binder used for road pavements construction.