The biolubricant term applies to all lubricants that biodegrade rapidly and which are non-toxic for human beings and aquatic habitats. Polyol esters-based biolubricants are preferable for all applications that not present risks to the environment due to it biodegradable manner. In this work, polyol ester-based biolubricant was synthesized through homogeneous acid-catalysed esterification of crude palm kernel fatty acids (CPKFAs) with polyhydric alcohol di-trimethylolpropane (di-TMP). The esterification process was optimized via D-optimal design of response surface methodology. The optimum condition for maximum yield and selectivity was observed at 5:1 molar ratio of CPKFAs to di-TMP, 5.6 h of reaction time, 156 °C of reaction temperature, and 1.5% of H₂SO₄ respectively. The optimum esterification process produced 83.2±0.5% yield of crude palm kernel fatty acids di-trimethylolpropane (CPKFAs-di-TMPTE) with 92.7±0.5% tetra-ester selectivity. The chemical structure and ester composition of synthesised tetra-ester were characterized by using FTIR, NMR (¹H and ¹³C) spectroscopy and GC chromatography analysis techniques. CPKFAs-di-TMP tetra-ester recorded oxidative stability temperature at 252 °C, thermal stability at 431 °C, pour point at -5 °C, flash point at 360 °C, and viscosity index of 142. The CPKFAs-di-TMP recorded its tribological properties with small friction coefficient with Newtonian fluids behaviour. The synthesised CPKFAs-di-TMPTE green biolubricant was compatible with some selected commercial lubricants. It can be categorised as ISO VG 68 lubricant and plausible for various industrial applications in tropical countries at medium-range operation temperature.

生物润滑剂术语适用于所有可快速生物降解且对人类和水生栖息地无毒的润滑剂。基于多元醇酯的生物润滑剂因其可生物降解的方式而适用于所有不会对环境造成风险的应用。在这项工作中，通过粗棕榈仁脂肪酸 (CPKFA) 与多元醇二三羟甲基丙烷 (di-TMP) 的均相酸催化酯化反应合成了多元醇酯基生物润滑剂。通过响应面方法的 D 优化设计优化酯化过程。在 CPKFAs 与 di-TMP 的摩尔比为 5:1、反应时间为 5.6 h、反应温度为 156 °C 和 H ₂ SO ₄为 1.5% 的条件下观察到最大产率和选择性的最佳条件分别。最佳酯化工艺产生了 83.2±0.5% 的粗棕榈仁脂肪酸双三羟甲基丙烷 (CPKFAs-di-TMPTE)，四酯选择性为 92.7±0.5%。合成的四酯的化学结构和酯组成通过红外光谱、核磁共振（¹ H 和¹³C) 光谱和GC色谱分析技术。CPKFAs-di-TMP 四酯的氧化稳定性温度为 252 °C，热稳定性为 431 °C，倾点为 -5 °C，闪点为 360 °C，粘度指数为 142。 TMP 用牛顿流体行为记录了其摩擦系数小的摩擦学特性。合成的 CPKFAs-di-TMPTE 绿色生物润滑剂与一些选定的商业润滑剂兼容。它可以归类为 ISO VG 68 润滑剂，适用于热带国家中中等工作温度的各种工业应用。