Figure 4.

SEM image of the various composite laminates: (a) BA-ph; (b) BA-ph/PEN blends with 20 wt % PEN content; (c) the zoom in image of (b,d) BA-ph/PEN blends with 40 wt % PEN content; the arrows reflected the gaps between the matrix and GF in Figure 3a, as well as adhesion properties in Figure 3b–d; the ovals reflected the rough surface of GF and the smooth surface of the matrix; the rectangles marked the zoom in image of the adhesion properties of the composites in a particular area.