urethane both in hard phase and also at the interface of two phases,
soft and hard, and also the connection of the zeolite to ether groups
of polyol in the soft phase is considered the reason for such phenomena.
Therefore, the no homogeneity in the interaction of the
carbonyl groups and the increment of the zeolite particles which
can be connected to functional groups mentioned above, lead to
broadening the peak of carbonyl absorption in highly-loaded zeolite
MMM. The present description coincides with the observations
related to the N–H peaks. As can be observed, by increasing the
amount of zeolite, the peak of N–H group is broadened and transferred
into the lower frequencies. This phenomenon confirms that
the N–H groups are connected to the polar group in the zeolite.
As shown in Fig. 2, the peak of free carbonyl is broadened a little
and its intensity is reduced.