Fig. 2: Prerequisites for reinforcement by DCR and HPWPUE phase deformation.
From: Delayed crystallization response-inspired waterborne polyurethane with high performance
a Chemical structure of HPWPUE and its variants, highlighting the segments derived from the varying chain extenders (left) and isocyanates (right) investigated. b Stress-strain curves for HPWPUE and its seven variants: WPU-DBEDA, WPU-DETA, WPU-IPDA(NH), WPU-HMDI, WPU-HDI, WPU-MDI, and WPU-IPDI(OCN). c Bar chart comparing the σe, max and toughness values for HPWPUE and its variants. The error bars represent the standard deviation calculated from three independent measurements. d Polarized optical microscopic images of HPWPUE under varying horizontal stress ratios, with the analyzer oriented vertically (scale bar = 200 μm). e Differential modulus (dσe /dεe) plotted against εe. f Haward-Thackray plot of true stress versus (λ2 −1/λ), with an inset magnifying the range 0 ≤ λ2 -1/λ ≤ 100. The blue region represents the HPWPUE in the amorphous phase, while the red region indicates crystallization of the HPWPUE.
