Improvement of Physicochemical Characteristics of Monoepoxide Linoleic Acid Ring Opening for Biolubricant Base Oil

Table 3

Regression coefficients of the predicted quadratic polynomial model for response variables of the OOC% of HYOOA.

Variables	Coefficients (𝛽), OOC% (Y)	T	P	Notability
Intercept	1.63	5.19	0.0064	***
Linear
𝑋1	−0.31	1.76	0.2143
𝑋2	−0.55	5.73	0.0378	**
𝑋3	−0.11	0.23	0.6395
𝑋4	−0.064	7.548𝐸−003	0.9325
Quadratic
𝑋11	0.16	0.19	0.6699
𝑋22	1.18	8.1	0.0172	**
𝑋33	−0.078	0.65	0.4377
𝑋44	−1.01	1.47	0.2537
Interaction
𝑋12	0.13	0.51	0.4912
𝑋13	0.14	2.05	0.1830
𝑋14	−0.22	0.40	0.5423
𝑋23	−0.23	5.99	0.0344
𝑋24	1.02	8.22	0.0168
𝑋34	−0.017	8.374𝐸−003	0.9289
𝑅^2	0.87

Notes: 𝑋₁ = OA/MEOA ratio; 𝑋₂ = PTSA/MEOA ratio; 𝑋₃ = reaction temperature; 𝑋₄ = reaction time, **𝑃<0.05; ***𝑃<0.01. T : F-test value. See Table 2 for a description of the abbreviations.