As shown in Fig. 3, by increasing the amount of zeolite, the
peaks are transferred to higher degrees, i.e., less d-spacing, and
the peak intensity is enhanced. This result indicates the presence
of zeolite crystal particles among the polymer chains and their
appropriate distribution in the polymer structure. Moreover, the
peaks observed in the pure sample of polyurethane are observed
in the sample of polyurethane–zeolite in lower d-spacing or higher
angle range, too. This is because of generating the zeolite crystals
among the tiny crystals found in the polymer.