The polymerization of the resin subsequently proceeded at 60 °C for 48 h. The embedded samples were sectioned BYL719 chemical structure in ∼70 nm thick slices using a diamond knife. The sections were transferred to supported gold grids and stained with uranyl acetate and Pb-citrate. The samples were observed under a Carl-Zeiss Model LEO906 transmission electron microscope. The surface-response methodology was used to study the effect of the plasticizer concentration (Cg or Cs) and process temperature (Tp) on dependent variables (mechanical properties and solubility).
The levels of the independent variables were defined according to a 22 full-factorial central composite design (star configuration) (Table 1 and Table 2).
An analysis of variance (ANOVA), a multiple comparison test, and all statistical analyses were performed using the Statistica 6.0 software. The data were fitted to a second order equation (Eq. (2)) as a function of the independent variables. equation(2) Yi=b0+b1X1+b2X2+b12X1X2+b11X11+b22X22where bn are constant regression coefficients, Yi are dependent variables (puncture force (PF), puncture deformation (PD), tensile strength (TS), elongation at break (E), Young’s modulus (YM), and solubility (S)), and X1 and X2 are the coded independent variables (plasticizer concentration and process temperature, respectively). After the surface-response results, were obtained, Avelestat (AZD9668) optimization
of the process conditions was carried out by multi-response analysis TSA HDAC (Derringer & Suich, 1980). This method involves the transformation of response variables (Yi) to an individual function of dimensionless desirability (gi) (Eq. (4)), ranging from 0 (undesirable response) to 1 (desired response). From the geometric means of individual desires, the overall desirability function (G) (Eq. (3)) is obtained. G was later maximized using the software Mathematic 5.0. equation(3) G=(g1n1,g2n2,……,gknk)1/kwhere: equation(4) gi=Yi−YminYmax−Yminwhere Ymin is the response minimum value and Ymax is the response maximum value, k is the number of considered responses, and ni is the weight of each response. In the case of solubility, Eq. (4) had to be redesigned, so that the minimum values for these responses could be obtained (Eq. (5)). equation(5) gi=Ymax−YiYmax−Ymin Finally, the Tukey’s test was applied at a 5% significance level to compare means for mechanical, solubility, moisture content, barrier properties, and GAB parameters of glycerol and sorbitol films prepared using the optimal formulation. The amaranth flour contains 9.0 ± 0.4 g/100 g moisture, 2.1 ± 0.0 g/100 g ash, 7.9 ± 0.2 g/100 g lipids, 14.1 ± 0.3 g/100 g protein, and 75.8 ± 0.2 g/100 g starch (among which 11.9 ± 0.3 g/100 g was amylose) (dry basis).