Fig. 3: Physico-mechanical properties of two experimental and one commercial reference composite.
From: Lignin-derived bisguaiacol P vinyl ester as a bisphenol A-free resin alternative
a Degree of conversion (DC in %) measured at time points 30 min, 2 h, 72 h, and 1 week. b Elastic modulus (EM in GPa) measured by the non-destructive impulse excitation technique (IET). c Flexural strength (FS in MPa) is measured by four-point bending. d Curves of the Weibull characteristic strength, which is the strength occurring at a failure probability of 63.2%. e Knoop hardness (KH in kgf/mm2). f KH was measured after water immersion for 1 week, 1 month, 4 months, 6 months, and 1 year. g Water absorption (Wa) and water solubility (Ws) in µg/mm3. h The color comparison was measured through Delta E (note that the commercial product contained a color-stabilizing BHT compound). In (a, f–h), error bars represent the mean ± standard deviation. In (b, c, e), the horizontal lines within each box plot indicate, from top to bottom: the maximum value, upper quartile, median, lower quartile, and minimum value.
