ABSTRAKPada penelitian ini telah berhasil disintesis gemuk bio kalsium kompleks yang ditambahkan dengan aditif asam borat. Gemuk yang dihasilkan berbahan dasar minyak kelapa sawit dan sabun kalsium kompleks sebagai thickening agent-nya. Sintesis gemuk tersebut dilakukan dengan cara melakukan reaksi saponifikasi antara sabun kalsium kompleks secara insitu dalam minyak RBDPO terepoksidasi menggunakan bejana bertekanan. Selanjutnya dilakukan pendinginan dan homogenisasi serta penambahan aditif asam borat yang divariasikan komposisinya: 0%, 1%, 3%, 5%, dan 7% dari berat gemuk. Pengujian terhadap gemuk bio yang dihasilkan meliputi uji penetrasi, uji dropping point dan uji four ball. Gemuk terbaik yang dihasilkan memiliki jumlah keausan terkecil yaitu 0.8 mg, pada penambahan asam borat sebanyak 5% berat.

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ABSTRACTIn this research, complex calcium bio grease with solid aditif boric acid has been synthesized. Synthesized grease is made by palm oil and complex calcium soap as thickening agent. Synthesizing process of grease has done by doing saponification reaction of complex calcium soap in situ with RBDPO use pressurized vessel. Then, continued by cooling and homogenizing also adding boric acid as aditif which is variated their composition: 0%, 1%, 3%, 5%, and 7% wt. Performance test of produced grease include penetration test, dropping point test, and four ball test. The best grease produced is has minimum wear number: 0.8 mg, for 5% composition of boric acid.