Volume 48, No 3, 2026, Pages 659-670
Download full text in PDFFriction and Wear Performance of Rice Bran–Castor Oil Biolubricant Using Hybrid Microcrystalline Cellulose and Hexagonal Boron Nitride Additives
Authors:
M.N. Thejaswini 
,
U. Bhavana 
,
D. Shrinivasa ,
R. Hemanth ,
A. Anand ,
P.B. Bharath ,
B. Suresha
DOI: 10.24874/ti.2309.07.26.09
Received: 4 May 2026
Revised: 16 June 2026
Accepted: 16 July 2026
Published: 15 September 2026
Abstract:
High-performance bio-based lubricants with improved tribological properties are becoming more popular as substitutes for conventional lubricants. Microcrystalline cellulose (MCC) at concentrations of 0.1–0.5 wt% and a hybrid MCC/hexagonal boron nitride (h-BN) additive were added to a binary bio-lubricant developed in this study utilizing an 85:15 ratio of Rice Bran Oil (RBO) and Castor Oil (CO). A four-ball tribometer was used to assess tribological performance in terms of wear scar diameter (WSD) and coefficient of friction (CoF). The findings demonstrated that the addition of 0.5 wt% MCC reduced the WSD from 1159 to 922 µm (20.45%) and the CoF from 0.121 to 0.063 (47.93%) when compared to the neat bio-lubricant. Also, in comparison to 0.5 wt% MCC, the hybrid formulation MB3, which contained 0.25 wt% MCC and 0.25 wt% h-BN, showed the lowest CoF (0.061) and WSD (892 µm), equating to additional reductions of 3.2% and 3.3%, respectively. When comparing the additive-containing formulations to the neat bio-lubricant, SEM studies of the worn surfaces revealed relatively smoother and less damaged wear scars. These findings demonstrate that, under the tested conditions, adding MCC and MCC/h-BN can improve the RBCO-based lubricant's evaluated wear performance and friction.
Keywords:
Bio-lubricant, Rice bran oil–castor oil blend, Additives, Four-ball tribometer, Tribological performance
