Table 2.

Matrix of the central composite rotational design (CCRD) (coded and real variables).

Treatments	Independent Variable			Dependent Variable
	Agar-Agar (g)	Chitosan (g)	Glycerol (%m Glycerol/m Dry Polymer Mass)	TS (MPa)	EB (%)
1	−1 (0.20)	−1 (0.40)	−1 (18.09)	3.03 ± 0.74	41.10 ± 2.62
2	+1 (0.80)	−1 (0.40)	−1 (18.09)	10.36 ± 0.94	25.60 ± 2.29
3	−1 (0.20)	+1 (0.60)	−1 (18.09)	11.15 ± 2.96	30.76 ± 2.82
4	+1 (0.80)	+1 (0.60)	−1 (18.09)	6.79 ± 2.86	24.46 ± 3.48
5	−1 (0.20)	−1 (0.40)	+1 (41.09)	1.31 ± 0.19	17.99 ± 0.32
6	+1 (0.80)	−1 (0.40)	+1 (41.09)	5.63 ± 1.56	17.45 ± 2.65
7	−1 (0.20)	+1 (0.60)	+1 (41.09)	4.39 ± 1.02	34.07 ± 3.90
8	+1 (0.80)	+1 (0.60)	+1 (41.09)	7.09 ± 1.03	25.23 ± 3.20
9	−1.68 (0.00)	0 (1.00)	0 (30.00)	3.11 ± 0.18	51.04 ± 3.64
10	+1.68 (1.00)	0 (1.00)	0 (30.00)	9.47 ± 2.53	14.90 ± 2.20
11	0 (0.50)	−1.68 (0.00)	0 (30.00)	4.13 ± 0.71	26.30 ± 3.78
12	0 (0.50)	+1.68 (2.00)	0 (30.00)	4.57 ± 1.56	17.88 ± 2.77
13	0 (0.50)	0 (1.00)	−1.68 (10.00)	10.59 ± 1.84	23.37 ± 3.10
14	0 (0.50)	0 (1.00)	+1.68 (50.00)	3.54 ± 0.69	18.18 ± 3.91
15	0 (0.50)	0 (1.00)	0 (30.00)	8.88 ± 1.04	22.95 ± 1.83
16	0 (0.50)	0 (1.00)	0 (30.00)	8.08 ± 2.09	22.16 ± 3.21
17	0 (0.50)	0 (1.00)	0 (30.00)	10.467 ± 0.28	21.00 ± 1.68

TS: tensile strength at break; EB: elongation at break.