Diesters Biolubricant Base Oil: Synthesis, Optimization, Characterization, and Physicochemical Characteristics

Table 2

D-optimal design arrangement and yield % response of OLHYOOD.

Run no.	Coded independent variable levels				Response
	OL^a/HYOOA^b	SA^c/HYOOA	Temperature	Time	Yield^d
	(mol/mol, 𝑋1)	(mol/mol, 𝑋2)	(°C, 𝑋3)	(h, 𝑋4)	(%, 𝑌)
1	2	0.70	90	5	38.7
2	2	1.30	110	7	66.7
3	2	1.30	110	7	78.3
4	4	1.00	100	6	45.7
5	3	1.15	100	6	41.5
6	2	1.00	90	7	75.9
7	4	1.00	90	5	47.5
8	4	1.00	110	7	84.4
9	4	0.70	110	5	45.9
10	4	0.70	110	5	50.1
11	2	1.30	90	5	43.1
12	2	1.30	90	5	46.4
13	2	0.70	110	7	88.7
14	4	1.30	110	6	60.2
15	3	1.30	110	5	44.5
16	2	0.70	110	7	51.5
17	3	0.70	100	6	58.1
18	2	1.00	110	5	68.2
19	4	1.30	90	7	78.3
20	4	0.70	90	7	55.7
21	3	1.00	110	6	76.7
22	2	1.00	100	6	65.9
23	3	1.00	90	6	69.5
24	4	1.30	100	5	50.8
25	4	1.30	90	7	72.3

Notes: oleyl alcohol (a); 9(12)-hydroxy-10(13)-oleioxy-12(9)-octadecanoic acid (HYOOA) (b); sulfuric acid (c); yield % of oleyl 9(12)-hydroxy-10(13)-oleioxy-12(9)-octadecanoate (OLHYOOD) (d).